Axe
* 
Ice Path is a great stun for Berserker's Call and with a 
Eul's Scepter of Divinity can really catch Axe off guard.
* 
Dual Breath and 
Liquid Fire can be a devastating combination for Axe (especially if he takes Battle Hunger at level 1) before he has any natural regeneration sustain from items.
Additional:
* Ice Path neutralizes initiation attempts with Berserker's Call, and its long area of effect discourages follow-ups from Axe's teammates until Axe buys 
Black King Bar.
* Ice Path serves as a large obstacle to stop Axe from chasing down fleeing stragglers to kill with Culling Blade until Axe buys Black King Bar.
* Jakiro's many damage-per-second skills prevent Axe from initiating with his Blink Dagger. Forcing Axe to buy Black King Bar prematurely to protect himself against Jakiro's abilities and counter-initiaions.
Naga Siren
* Jakiro's damage over time abilities can clear Naga Siren's illusions and can hurt real Naga Siren even for the duration of 
Song of the Siren.
* Naga Siren is not a hero that likes to go for Black King Bar, and that makes her very vulnerable to Jakiro's damage over time in every phase of the game.
Additional:
* Jakiro's damage over time abilities can clear Naga Siren's illusions and can hurt real Naga Siren even for the duration of Song of the Siren.
* Since Naga Siren is a hero who barely goes for Black King Bar, this can make her very vulnerable to Jakiro's damage over time in every phase of the game.
Axe
* Heroes that relies on armor or other type of physical damage negation are easy for Gyrocopter to take down during the early game with his magical damage: 
Axe, 
Dragon Knight, 
Sven.
Naga Siren
* 
Flak Cannon and 
Call Down can easily clear Naga Siren's illusions.
Axe
* Special mention to 
Timbersaw as he has a way to deal with Axe in the laning stage, but still needs to be careful about Berserker's Call stun, the pure damage from Counter Helix and Culling Blade finishing him off before he can escape or heal from his passive.
Additional:
* 
Whirling Death reduces Axe's strength by 15%, which makes him less durable, especially from early game. It's also stackable.
* 
Blade Mail are not effective against attribute changes, and 
Timber Chain can wait out Blade Mail's duration to wear off.
* 
Reactive Armor makes it harder for Axe to finish off Timbersaw with 
Culling Blade.
* 
Chakram disarms Timbersaw, which makes Axe's 
Counter Helix useless against him.
* All Timbersaw skills deal pure damage, which bypass Axe's high armor or bonus armor from 
Berserker's Call.
Naga Siren
* Timbersaw's innate durability provided by Reactive Armor is very hard to deal with as Naga Siren as she mostly relies on sustained damage rather than burst damage unless if she is played as Nuker.
* Timbersaw's high pure damage and low-cooldown area-of-effect nukes which are Whirling Death, Timber Chain, Chakram and 
Flamethrower from 
Aghanim's Shard can also destroy Naga Siren's illusions very fast.
* Timbersaw is a common 
Lotus Orb wielder which allows him to reflect 
Ensnare back at Naga SIren.
Axe
* Heroes who can stop Axe from getting close will severely inhibit his presence in fights: 
Bristleback, 
Crystal Maiden, 
Batrider, 
Arc Warden, 
Winter Wyvern, 
Clockwerk
Naga Siren
* Many stacks of 
Sticky Napalm, combined with 
Flamebreak and 
Firefly, allows Batrider to destroy illusions from 
Mirror Image.
* If Batrider can manage to destroy all illusions from Naga Siren, he will be able to use 
Flaming Lasso on the real one, and will be able to drag her toward his team, potentially preventing Naga Siren from escaping with Song of the Siren.
Additional:
* Many stacks of Sticky Napalm, combined with Flamebreak and Firefly, allows Batrider to destroy illusions from Mirror Image.
* If Batrider can manage to destroy all illusions from Naga Siren, he will be able to use Flaming Lasso on the real one, and will be able to drag her toward his team, potentially preventing Naga Siren from escaping with Song of the Siren.
Axe
* Heroes who can stop Axe from getting close will severely inhibit his presence in fights: Bristleback, Crystal Maiden, Batrider, Arc Warden, Winter Wyvern, Clockwerk
Naga Siren
* Heroes with long cast animations can be continuously interrupted by Battery Assault: 
Centaur Warrunner, 
Jakiro, 
Leshrac, 
Naga Siren, 
Underlord.
Axe
* Ranged heroes that can easily harass Axe: 
Drow Ranger, 
Sniper, 
Lion.
Naga Siren
* Lion may upgrade 
Mana Drain, 
Hex and 
Finger of Death through Talent Tree and Aghanim's itens to make them affect secondary targets or turn them into AoE abilities. This can make things difficult for heroes like 
Phantom Lancer, Naga Siren and 
Terrorblade, who rely on illusion armies.
Additional:
* Both Hex and Mana Drain destroy Naga Siren's illusions in an instant, making it hard for her to teamfight or push against a team with Lion. If Lion chooses the AoE effect talent for Hex or the shard for multi-target Mana Drain, it can negate her pushing potential entirely.
* 
Earth Spike is an AoE disable with good damage. If used well, it can help distinguish the true Naga Siren by the damage they take (illusions take more damage).
Axe
* Long lockdown is a great way to deal with Axe to prevent Berserker's Call from being used, heroes such as 
Legion Commander, 
Beastmaster and 
Primal Beast are good examples of this.
Additional:
* Berserker's Call will be a stun for Primal Beast and not much else due to Trample making him unable to attack.
* 
Battle Hunger is neglitable because Primal Beast has a much bigger health than Axe, so he does not need to fear being slowed, or his other abilities including Counter Helix or even a Blade Mail.
* Getting Primal Beast low enough to use a successful Culling Blade can be very difficult due to his massive health advantage over most heroes.
* Not ability related but Primal Beast does not need to fear Axe in lane, as Trample, combined with Uproar and Onslaught will do a ton of damage even if Axe has a 
Vanguard.
Naga Siren
* Illusion heroes will struggle against Primal Beast's area damage capability, such as 
Chaos Knight, Naga Siren, Terrorblade.
Naga Siren
* Dawnbreaker can easily clear waves of Naga Siren's illusions from Mirror Image with 
Starbreaker, 
Celestial Hammer and 
Solar Guardian.
* Aghanim's Shard upgraded Starbreaker will allow Dawnbreaker to dispel Ensnare and freely attack Naga Siren during Song of the Siren when combined with Black King Bar, a common item on Dawnbreaker.
* Solar Guardian allows Dawnbreaker to counter any attempts of Naga Siren and rejoin her team with Solar Guardian when they require it. 
Aghanim's Scepter upgraded Solar Guardian can also give Dawnbreaker's allies evasion while Dawnbreaker is airborne for it's duration, as Naga Siren mainly relies on direct attacks in order to deal damage.
Additional:
* Dawnbreaker can easily clear waves of Naga Siren's illusions from Mirror Image with Starbreaker, Celestial Hammer and Solar Guardian.
* Aghanim's Shard upgraded Starbreaker will allow Dawnbreaker to dispel Ensnare and freely attack Naga Siren during Song of the Siren when combined with Black King Bar, a common item on Dawnbreaker.
* Solar Guardian allows Dawnbreaker to counter any pushing attempts of Naga Siren and rejoin her team with Solar Guardian when they require it. Aghanim's Scepter upgraded Solar Guardian can also give Dawnbreaker's allies evasion while Dawnbreaker is airborne for it's duration, as Naga Siren mainly relies on direct attacks in order to deal damage. Solar Guardian can also be used after Naga Siren uses Song of the Siren near her allies to either escape from or counter-initiate against them.
Axe
* 
Enrage reduces the damage from Blade Mail and Counter Helix to a minimum, forcing Axe to play around Ursa's ultimate ability.
* 
Overpower and 
Fury Swipes stacks damage overwhelming for Axe, despite his high health.
Naga Siren
* Zeus's abilities deal high amounts of burst magical damage, which ignores Naga Siren's high armor.
* 
Arc Lightning is a good way to destroy Naga Siren's illusions due to it's capabilities to bounce between enemies.
* 
Static Field from Aghanim's Shard can automatically hit everything in a big radius, taking a huge chunk of health out of Naga Siren's illusions, regardless of how much health they have.
Axe
* 
Disruption will save Shadow Demon's teammates from being killed by Counter Helix or Culling Blade.
* 
Demonic Purge slows Axe to a crawl, making him nearly useless after initiating. If Shadow Demon has Aghanim's Scepter, it will also break Counter Helix.
* 
Demonic Cleanse clears Battle Hunger and Aghanim's Shard Counter Helix Damage Reduction, both allowing targets to escape and reducing your own survivability.
Additional:
* While it is unwise to encounter Axe alone, Disruption can be used to save your allies from Axe's initiate Berserker's Call, or, if timed correctly, from his Culling Blade.
* Illusions spawned from Axe has the Counter Helix passive, which with deal some nasty damage if an enemy focuses them
* Your upgraded Demonic Purge breaks Axe's primary damage output: Counter Helix, This can be used on him during Berserker's Call to seriously hinder him.
* Demonic Cleanse will clear Battle Hunger, which is Axe's method of catching heroes, and Shard upgraded Counter Helix's Damage Reduction, which is one of Axe's primary survivability abilities.
Axe
* Venomancer's slows and magical damage-over-time work well against Axe's complete lack of mobility.
* 
Plague Ward is especially useful for slowing down Axe, and revealing him before he initiates, as well as putting his 
Blink Dagger on cooldown.
Additional:
* Venomancer's slows and magical damage-over-time work well against Axe's complete lack of mobility.
* Plague Wards is especially useful for slowing down Axe, and revealing him before he initiates, as well as putting his Blink Dagger on cooldown.
* For the same reasons, Venomancer is a good ally for Axe when the situation is reversed.
Naga Siren
* Mirror Image's illusions increase Echo Slam's damage.
Additional:
* Earthshaker's strong AoE abilities can clear Naga Siren's illusions, or at least make it easier to distinguish the real one by the damage they take.
* 
Echo Slam deals more damage against more enemies, which can be devestating against Naga Siren and her illusions.
Naga Siren
* All of Leshrac's abilities, especially 
Pulse Nova, can easily deal with Naga Siren's illusions.
* Aghanim's Scepter gives Leshrac access to 
Nihilism ability, that allows him to turn himself along with Naga Siren and her illusions to turn ethereal. And to make things worse, Nihilism can slow Naga Siren and her illusions, make them more vulnerable to magical damage and unable to fight back while Leshrac moves faster and does not take increased magical damage for it's duration.
Axe
* 
Decrepify can be used on allies to prevent them from attacking Axe and triggering Counter Helix during Berserker's Call. He can also cast it on Axe to prevent anyone from attacking him.
* 
Life Drain can be used to heal himself or allies caught in Berserker's Call, preventing them from dropping low enough for Axe to kill them with Culling Blade.
Naga Siren
* Avalanche and Toss combo makes short work of Mirror Image's illusions.
* Tiny's cleave with Tree Grab and area of effect damage with Tree Volley will easily wipe out illusions.
Naga Siren
* 
Mortimer Kisses can make quick work of Naga Siren's illusions.
* 
Scatterblast and 
Firesnap Cookie's AoE damage are also decent ways to deal with Naga's illusions.
Axe
* 
Infernal Blade's damage is calculated by a percentage of maximum health, meaning that it will hurt Axe more than most normal attacks, negating some of his durability.
* Doom can pick up several different abilities from neutral creeps using 
Devour, some of which can be annoying to Axe.
* Mud Golem, Dark Troll Summoner, Harpy Stormcrafter, Satyr Mindstealer or Satyr Tormenter are good examples.
* Doom's naturally low attack speed makes Counter Helix less likely to proc, and his high base health allows him to take a few Helixes with no danger.
* 
Doom makes Axe less disruptive, preventing him from using his skills or items. At level 25, there is a branch of the talent tree that makes Doom apply Break, allowing Doom to disable Counter Helix, making Axe effectively useless for a lengthy duration.
Additional:
* Infernal Blade deals scaling damage and is useful against high HP targets such as Axe.
* Doom has low attack speed because of his high Base-Attack-Time, poor agility gain and limited attack-speed granting items which are commonly built. This means Doom will trigger Counter Helix less often and thus is an unideal target for initiation.
* Doom has naturally high HP so it takes longer for Doom to be brought down to the killing threshold of Culling Blade.
* Axe is highly reliant on his abilities and items to be effective during a fight. Without the usage of Berserker's Call and Blink Dagger due to Doom, Axe offers very little in the way of damage, effectively removing him from a fight.
Naga Siren
* Heroes with AoE nukes will clear her illusions in no time, especially if they are percentage-damage-based, like Underlord's 
Firestorm, 
Elder Titan's 
Earth Splitter, 
Enigma's 
Midnight Pulse, 
Zeus's Arc Lightning, Jakiro's 
Liquid Frost from Aghanim's Shard etc.
Axe
* Heroes who can stop Axe from getting close will severely inhibit his presence in fights: Bristleback, Crystal Maiden, Batrider, Arc Warden, Winter Wyvern, Clockwerk
Axe
* Enigma can be a perfect counter-initiator with his ultimate. A perfectly timed Black Hole will turn the tide of any initiation, especially from heroes like; 
Spirit Breaker, Legion Commander, Axe, 
Puck, and 
Slardar.
Naga Siren
* Heroes with AoE nukes will clear her illusions in no time, especially if they are percentage-damage-based, like Underlord's Firestorm, Elder Titan's Earth Splitter, Enigma's Midnight Pulse, Zeus's Arc Lightning, Jakiro's Liquid Frost from Aghanim's Shard etc.
Axe
* Long ranged disables, especially those that pierce spell immunity, cancel Black Hole: Beastmaster's 
Primal Roar, 
Bane's 
Fiend's Grip, 
Faceless Void's 
Chronosphere, 
Magnus's 
Reverse Polarity, Axe's Berserker's Call, 
Pudge's
Meat Hook.
Axe
* 
Sun Ray allows Phoenix to heal any allies caught in Berserker's Call while burning away Axe's high HP at the same time.
* 
Icarus Dive and 
Fire Spirits puts Axe's Blink Dagger on cooldown.
* Axe's slow attack speed makes it difficult for him to destroy 
Supernova on his own.
Naga Siren
* 
Sand King and 
Phoenix have many tools to deal with multiple enemies at once, which will work well against a crowd of illusions.
Naga Siren
* Song of the Siren does not affect Supernova, which allows her and her team to focus the egg while the enemy team is affected by sleep.
* Phoenix cannot use Icarus Dive for escaping when rooted by Ensnare.
* However, Phoenix has many area-of-effect abilities that allow him to clear Naga Siren's illusions from Mirror Image.
Naga Siren
* Since Naga Siren is a hero who barely goes for Black King Bar, she is vulnerable to nukers with strong magical damage and big area-of-effect spells in every game more than any other carry heroes: Sand King, Jakiro, Leshrac, 
Lina, 
Earthshaker, Zeus.
Naga Siren
* Heroes that rely on illusions typically spawn very strong illusions inside Dark Seer Wall of Replica that he can use against them or their team: Phantom Lancer, Chaos Knight, Naga Siren, Terrorblade.
Naga Siren
* 
Keeper of the Light can stall pushes with 
Illuminate. This makes him strong against pushing heroes: Terrorblade Naga siren 
Nature's Prophet and 
Anti-Mage
Naga Siren
* Heroes who are reliant on illusions: Chaos Knight, Phantom Lancer, Naga Siren.
Additional:
* Centaur's 
Retaliate will harm all attacking enemies, which will allow Centaur Warrunner to see which is the real Naga Siren.
* A well timed 
Hoof Stomp followed by 
Double Edge will clear all Naga's illusions and prevent Naga Siren from escaping with Song of the Siren.
Axe
* Because Exorcism's damage is not reduce by damage block abilities or items, Death Prophet can be very good against heroes who rely on armor to survive: Axe, Terrorblade, 
Morphling, Dragon Knight
Naga Siren
* Heroes with summons and illusions can find themselves easily bested by Lina, like 
Broodmother, Nature's Prophet, 
Chen, Terrorblade, Naga Siren, 
Visage, 
Wraith King, 
Lycan, Phantom Lancer, 
Shadow Shaman.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, 
Bloodseeker, 
Witch Doctor.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, 
Luna, 
Medusa, 
Templar Assassin, 
Gyrocopter, 
Muerta.
Naga Siren
* Heroes that heavily depend on illusions or summons, (Naga Siren, Terrorblade, Phantom Lancer, Lycan,...) are vulnerable to Sleight of Fist and even more so if Ember Spirit has 
Battle Fury.
Naga Siren
* Heroes who are reliant on illusions or summons: Chaos Knight, Broodmother, Naga Siren.
Axe
* Long lockdown is a great way to deal with Axe to prevent Berserker's Call from being used, heroes such as Legion Commander, Beastmaster and Primal Beast are good examples of this.
Axe
* Mana Shield reduces the effectiveness of Counter Helix.
* Stone Gaze makes it very difficult for Axe to initiate on Medusa and her allies.
Naga Siren
* Medusa's 
Split Shot and 
Mystic Snake combined with 
Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's 
Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Additional:
* Medusa's Split Shot and Mystic Snake combined with Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Axe
* Axe can take advantage of Medusa's awfully low HP to insta-kill her with Culling Blade, making it extremely difficult for her to farm for items to compensate for the lack of strength during early and mid-game while Axe is continuously harassing around.
Naga Siren
* Heroes that build 
Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: 
Riki, Naga Siren, Terrorblade, 
Juggernaut, 
Spectre, 
Slark.
Axe
* Feast makes it impossible to for Lifestealer to be culled with Culling Blade and also deals high damage to Axe due to his naturally high health.
* However, Berserker's Call and Counter Helix can pierce through the 
Rage, and if Axe has allies with him against Lifestealer, Lifestealer may go down very quickly.
Naga Siren
* Heroes with illusions: Chaos Knight, Naga Siren, Phantom Lancer, Terrorblade
Naga Siren
* Luna's 
Moon Glaives and 
Lunar Blessing can clear waves of Naga Siren's illusions from Mirror Image.
* Once Naga Siren's illusions are cleared with Aghanim's Shard upgraded Moon Glaives, 
Eclipse can often finish off Naga Siren before she can escape with Song of the Siren.
* A well-timed Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Lucent Ministun talent can be casted at long range and allow Luna to burst down Naga Siren faster and repetively stun Naga Siren, preventing her from escaping with Song of the Siren and 
Town Portal Scroll without getting caught in it's range.
* Luna is a natural Black King Bar wielder unlike Naga Siren who barely goes for it, which allows Luna to freely attack Naga Siren during Song of the Siren and potentially get rid of the most of the damage and crowd-control from Naga Siren.
Additional:
* Luna's Moon Glaives and Lunar Blessing can clear waves of Naga Siren's illusions from Mirror Image, especially when combined with 
Gleipnir and 
Manta Style. Aghanim's Shard upgraded Moon Glaives can also be used to destroy Naga Siren's illusions and damage the real Naga Siren if they are too close to Luna while also reducing any damage Naga Siren inflicts on Luna for their duration.
* Once Naga Siren's illusions are cleared, Eclipse can often finish off Naga Siren before she can escape with Song of the Siren.
* A well-timed Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Lucent Ministun talent can be casted at long range and allow Luna to burst down Naga Siren faster and repetively stun Naga Siren, preventing her from escaping with Song of the Siren and Town Portal Scroll without getting caught in it's range.
* Luna is a natural Black King Bar wielder unlike Naga Siren who barely goes for it, which allows Luna to freely attack Naga Siren during Song of the Siren and potentially get rid of the most of the damage and crowd-control from Naga Siren.
Naga Siren
* Heroes that create illusions: Spectre, 
Shadow Demon, Phantom Lancer, Naga Siren, Chaos Knight, Terrorblade) or bring other units into the fight (such as Nature's Prophet, 
Lone Druid, Chen, 
Enchantress, 
Meepo and Arc Warden) can cause Eclipse to strike the illusions/summons unintentionally. However, in many cases Moon Glaives can resolve this issue and eliminate them before activating Eclipse, but that will require lots of farming for right-click items.
Axe
* Frequent healing from 
Death Pulse and 
Mekansm makes it difficult for Axe to finish off targets with Culling Blade.
* 
Ghost Shroud's instant cast time allows Necrophos to turn ethereal before being initiated on by Berserker's Call. This prevents him from attacking Axe while taunted, thus lowering the chance to proc Counter Helix.
* Axe's high health is relatively ineffective against 
Heartstopper Aura's percentage-based health degeneration.
* 
Reaper's Scythe stops Axe's game plan of using Berserker's Call multiple times and since he's in the middle of the fight, this spell is very easy to grab kills onto him.
Additional:
* Frequent healing from Death Pulse makes it difficult for Axe to finish off targets with Culling Blade.
* Reaper's Scythe negates Axe's tankiness, and can kill him quickly after initiation if Axe's health is low enough.
* Heartstopper Aura can be very effective against Axe due to Axe's high strength gain.
* However, bear in mind that Berserker's Call can prevent Necrophos from using his Ghost Shroud to defend his fragile self from physical damages. And Heartstopper Aura can unintentionally help Axe to trigger his Counter Helix more frequently while also hurting Necrophos with Blade Mail during activation.
* Nonetheless Heartstopper Aura is not considered as a normal attack, thus it will not trigger Counter Helix, so anyone who wrote the statement above should be awarded with MVP and considered a TI champion purely for the innovation of new mechanics.
Naga Siren
* Illusions make it difficult for Necrophos to target his Reaper's Scythe correctly, thus giving illusion heroes like Chaos Knight or Naga Siren an edge against Necrophos.
Axe
* Long lockdown is a great way to deal with Axe to prevent Berserker's Call from being used, heroes such as Legion Commander, Beastmaster and Primal Beast are good examples of this.
Naga Siren
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, Chaos Knight, Terrorblade, Naga Siren
Naga Siren
* Song of the Siren lasts long enough to prevent a successful 
Duel (but only if Naga wasn't the target).
Axe
* Axe can take advantage of Chen jungling and gank him more often with Blink Dagger and Berserker's Call combination.
* Counter Helix can clear waves of Chen's creeps if they are too close to Axe.
* Berserker's Call combined with Blade Mail and Culling Blade can often kill Chen before he can save himself with 
Hand of God.
* However, Hand of God and 
Divine Favor can make it hard for Axe to finish off Chen's allies with Culling Blade when Chen is not target for Axe.
Naga Siren
* Naga Siren can make landing Chen's combo very hard due to her being an illusion hero thanks to Mirror Image.
* 
Rip Tide can deal big damage to Chen and reduce Chen's armor, as well as easily kill all of Chen's creeps.
* Naga Siren often builds 
Radiance, which allows her to quickly clear Chen's creeps.
* Ensnare will prevent Chen from escaping.
* With Aghanim's Scepter, Naga Siren can get access to 
Reel In, which can separate Chen from his creeps and draw him closer to Naga Siren and her team to finish her off. To make things worse, Chen has no way to cancel Reel In on his own, and must rely on outside from {U:Centaur Conqueror} or {U:Mud Golem} under his control.
* Carry or Nuker Naga Siren can often finish off Support Chen before he can have a chance to activate Hand of God.
Additional:
* Naga Siren can make landing Chen's combo very hard due to her being an illusion hero.
* Rip Tide can deal big damage to Chen and reduce Chen's armor, as well as easily kill all of Chen's creeps.
* Naga Siren often builds Radiance, which allows her to quickly clear Chen's creeps.
* Ensnare will prevent Chen from escaping.
* With Aghanim's Scepter, Naga Siren can get access to Reel In, which can separate Chen from his creeps and draw him closer to Naga Siren and her team to finish her off. To make things worse, Chen has no way to cancel Reel In on his own, and must rely on outside from {U:Centaur Conqueror} or {U:Mud Golem} under his control.
* Carry or Nuker Naga Siren can often finish off Support Chen before he can have a chance to activate Hand of God.
Axe
* Berserker's Call and Counter Helix will still hit targets inside of a defensive 
Sprout.
* Counter Helix clears treants in no time.
* Nature's Prophet's low damage is unlikely to hurt Axe until the very late game.
* Nature's Prophet's low mobility makes him very easy for Axe to chase down or initiate, especially when affected by Battle Hunger.
Naga Siren
* Naga Siren is a natural split-pusher. With Rip Tide, she will easily out-push Nature's Prophet, farming his treants in the process.
* Ensnare prevents 
Teleportation. Even if he hides inside Sprout, Song of the Siren lasts long enough to prevent him from escaping.
Additional:
* Naga Siren is a natural split-pusher. With a Radiance equipped, she will easily keep the lanes pushed out, therefore keeping backdoor protection enabled and preventing Nature's Prophet from dealing building damage.
* Ensnare can prevent Teleportation. Aghanim's Scepter upgraded Ensnare can also affect Nature's Prophet even if he is spell immune. And Reel In from Aghanim's Scepter can also be used to separate Nature's Prophet from his treant and bring him close to Naga Siren and her team to burst him down.
* Song of the Siren will stop Nature's Prophet from escaping even if he has hidden inside of Sprout. Aghanim's Shard upgraded Song of the Siren can also heal her allies and save them from Nature's Prophet.
Axe
* Terrorblade's low base health and lack of mobility make him an easy target for Axe to initiate on, and kill.
* Counter Helix will trigger from, and destroy many of Terrorblade illusions.
Additional:
* Berserker's Call and Counter Helix together can be devastating to Terrorblade, especially if Terrorblade has a lot of illusions. Their high attack speed will trigger Counter Helix a lot, and the pure damage will quickly slice through Terrorblade's low health and kill his illusions. More importantly, the Berserker's Call can pierce through spell immunity from Black King Bar, Terrorblade's only survival item besides Manta Style which cannot be used to dispel Berserker's Call. With enough burst damage by Axe's teammates, Terrorblade can be finished off even before taunt duration runs out and he gets a chance to save himself with 
Sunder.
* Culling Blade can finish off Terrorblade before he has the chance to Sunder due to his low health in the early to mid game. And every time Terrorblade or any of his allies are successfully killed by Culling Blade, Axe permanently gains armor from it, which in combination with armor items that Axe often purchases like Blade Mail, 
Crimson Guard, 
Assault Cuirass and 
Shiva's Guard can make Terrorblade's attacks only tickle Axe, even during Metamorphosis.
* Terrorblade's low base health and lack of mobility make him an easy target for Axe to initiate on, and kill.
Naga Siren
* Naga Siren can very easily dispel the 
Reflection with Mirror Image. And Besides Reflection that can be used to detect real Naga Siren, Terrorblade has no other ways to deal with Naga Siren's illusions. And what's worse is that Naga Siren can much easily detect the real Terrorblade due to 
Conjure Image having illusions having different colors. In addition, Terroblade is not a common Battle Fury nor Mjollnir wielder to counter this problem.
* Aghanim's Scepter upgraded Ensnare will allow Naga Siren to root Terrorblade even ithrough Black King Bar. And with Aghanim's Scepter, Naga Siren can get access to 
Reel In ability, which can allow her to pull Terrorblade toward herself and her team and away from his illusions, even through Black King Bar.
* Naga Siren can rapidly damage Terrorrblade and weaken Terrorblade's armor with Rip Tide, which combined with Terrorblade's low health and strength gain can almost completely discourage Terrorblade from even being present in teamfights. Rip Tide can also weaken armor of Terrorblade's illusions and damage them.
* Song of the Siren can be used to save an ally whom Terrorblade has used Sunder under the condition Naga Siren is quick enough to do it. And since Terrorblade has no "real" burst damage potential outside from Sunder, Naga Siren will usually have plenty of time to save an allied hero on which Sunder was used. Aghanim's Shard upgraded Song of the Siren can also heal her allies around her for it's duration, which allows Naga Siren to nullify effects of Sunder.
* However, Naga Siren's lack of burst damage can make it difficult for her to burst down Terrorblade before he can use Sunder unless Naga Siren has either Black King Bar or 
Linken's Sphere to protect herself against it or if she is played as Nuker.
Additional:
* Naga Siren can very easily dispel the Reflection with Mirror Image. And Besides Reflection that can be used to detect real Naga Siren, Terrorblade has no other ways to deal with Naga Siren's illusions. And what's worse is that Naga Siren can much easily detect the real Terrorblade due to Conjure Image having illusions having different colors. In addition, Terroblade is not a common Battle Fury nor Mjollnir wielder to counter this problem.
* Aghanim's Scepter upgraded Ensnare will allow Naga Siren to root Terrorblade even through Black King Bar. And with Aghanim's Scepter, Naga Siren can get access to Reel In ability, which can allow her to pull Terrorblade toward herself and her team and away from his illusions, even through Black King Bar.
* Naga Siren can rapidly damage Terrorrblade and weaken Terrorblade's armor with Rip Tide, which combined with Terrorblade's low health and strength gain can almost completely discourage Terrorblade from even being present in teamfights. Rip Tide can also weaken armor of Terrorblade's illusions and damage them.
* Song of the Siren can be used to save an ally whom Terrorblade has used Sunder under the condition Naga Siren is quick enough to do it. And since Terrorblade has no "real" burst damage potential outside from Sunder, Naga Siren will usually have plenty of time to save an allied hero on which Sunder was used. Aghanim's Shard upgraded Song of the Siren can also heal her allies around her for it's duration, which allows Naga Siren to nullify effects of Sunder.
* However, Naga Siren's lack of burst damage can make it difficult for her to burst down Terrorblade before he can use Sunder unless Naga Siren has either Black King Bar or Linken's Sphere to protect herself against it or if she is played as Nuker.
Axe
* Huskar is often played at low health to maximize the bonuses from 
Berserker's Blood, and also because his abilities cost health to use. This makes him especially vulnerable to Culling Blade.
* Berserker's Blood gives Huskar no protection against the pure damage of Culling Blade. Its attack speed bonus also means that Counter Helix will proc more often.
* Axe's tankiness and base health regeneration makes it hard for Huskar to take him down with 
Burning Spears.
Additional:
* Berserker's Call and Blade Mail can be used immediately after Huskar jumps on Axe with Life Break.
* Huskar's high attack speed procs Counter Helix repeatedly.
* Huskar's health loss from using his abilities make him a frequent target for Culling Blade.
Naga Siren
* Mirror Image can cause Huskar to Life Break the wrong target.
* Rip Tide reduces Huskar's already low armor.
* Song of the Siren allows teams to recover from Huskar's initiation, as well as the damage over time from Burning Spears.
Axe
* Culling Blade's instant kill is not prevented by Borrowed Time should Abaddon's health falls below the threshold.
Additional:
* Culling Blade ignores 
Borrowed Time should Abaddon's health falls under the threshold.
* 
Aphotic Shield does nothing against Berserkers Call and has to be used constantly to remove the very small mana cost of Battle Hunger in lane.
Naga Siren
* Song of the Siren completely wastes Abaddon Borrowed Time while keeping him in place.
* Naga Siren is able to simply dispel Abaddon's 
Curse of Avernus with Mirror Image before getting hit 4 times consecutively.
* Although Naga Siren's illusions can be easily destroyed by Aphotic Shield, Naga Siren can resolve that issue easily by purchasing 
Heart of Tarrasque to drastically increase her durability. Plus, the said item makes Naga Siren harder to be distinguished from her illusions.
Axe
* Berseker's Call catches Slark in 
Shadow Dance, wasting its duration and preventing him from escaping to regenerate.
* Unlike most disables, 
Dark Pact cannot dispel Berserker's Call and the output damage would be returned by Blade Mail.
Additional:
* Berserker's Call forces Slark to attack him, even during Shadow Dance.
* Counter Helix will hit Slark in Shadow Dance. It will also trigger frequently against Slark's high attack speed provided by Essence Shift stacks.
* Culling Blade finishes off Slark before he gets a chance to slip away and regenerate his health, preventing him from playing his typical hit-and-run style.
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: 
Phantom Assassin, Magnus, Slark, Riki, Faceless Void, 
Storm Spirit.
Axe
* Axe can disable 
Cloak and Dagger's invisibility with Berserker's Call, which forces Riki to attack him at a very bad angle.
* Axe has a very high HP pool, making it hard for you to kill him before you get big items - that is if you survive engaging him. Counter Helix ignores Riki's armor and goes straight for his tiny HP pool, totally ignoring 
Smoke Screen.
* Axe is a natural buyer of Blade Mail and Riki generally does not buy lifesteal items, causing Riki to kill himself when attacking due to your tiny HP pool.
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.
Axe
* 
Phantom Strike's extra attack speed will cause Phantom Assassin to trigger Counter Helix more often, which can be fatal for Phantom Assassin. Jumping on Axe with Phantom Strike is not a good idea for Phantom Assassin at all as it makes her a seriously easy target for a counter-initiation with Berserker's Call and Blade Mail.
* Most of Axe's abilities pierce Black King Bar, allowing him to lock down Phantom Assassin at any time.
* Berserker's Call greatly reduces Phantom Assassin's ability to crit hard against Axe and may cause her to kill herself when used with Blade Mail. Berserker's Call can also affect Phantom Assassin even if she has Black King Bar active as Berserker's Call can fully pierce spell immunity, making Berserker's Call one of the best abilities in the game against heroes like Phantom Assassin who wants to kill opponents quickly without being interrupted.
* Culling Blade can often kill Phantom Assassin before she can do anything due to her low health and strength gain. And every time Culling Blade successfully kills Phantom Assassin or any of her teammates, Axe gains permanent armor from it, which in combination with armor items that Axe often purchases like Blade Mail, Crimson Guard, Assault Cuirass and Shiva's Guard can make Phantom Assassin's attacks only tickle Axe.
* Aghanim's Shard upgraded Counter Helix can weaken Phantom Assassin's damage output, and if her attack damage is weak, 
Coup De Grace will also suffer from attack damage reduction as well.
Additional:
* Phantom Strike's extra attack speed will cause Phantom Assassin to trigger Counter Helix more often, which can be fatal for Phantom Assassin in the early game. Jumping on Axe with Phantom Strike is not a good idea for Phantom Assassin at all as it makes her a seriously easy target for a counter-initiation with Berserker's Call and Blade Mail.
* Most of Axe's abilities pierce Black King Bar, allowing him to lock down Phantom Assassin at any time.
* Berserker's Call greatly reduces Phantom Assassin's ability to crit hard against Axe, and may cause her to kill herself when used with Blade Mail. Berserker's Call can also affect Phantom Assassin even if she has Black King Bar active as Berserker's Call can fully pierce spell immunity, making Berserker's Call one of the best abilities in the game against heroes like Phantom Assassin who wants to kill opponents quickly without being interrupted.
* Culling Blade can often kill Phantom Assassin before she can do anything due to her low health and strength gain. And every time Culling Blade successfully kills Phantom Assassin or any of her teammates, Axe gains permanent armor from it, which in combination with armour items that Axe often purchases like Blade Mail, Crimson Guard, Assault Cuirass and Shiva's Guard can make Phantom Assassin's attacks only tickle Axe.
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.
Axe
* Heroes that are hard to gank: Axe, 
Death Prophet, Phantom Lancer, Slark, Centaur Warrunner, Bristleback, Medusa, 
Mars.
Naga Siren
* Ensnare and Song of the Siren can be used to cancel both, 
Tether and 
Relocate and to close the distance on Io.
* Rip Tide combined with illusions from Mirror Image often finish off Io before he can save himself with Tether or Relocate.
* 
Spirits's weak area-of-effect makes it a bad tool to deal with Naga Siren's illusions from Mirror Image.
* Once Naga Siren buys Aghanim's Scepter, she can gain access to Reel In, which not only allows her to cancel both, Tether and Relocate, but also to pull Io to herself and her team while he is affected with Ensnare, similarly to Batrider's Flaming Lasso.
* Aghanim's Shard upgraded Song of the Siren can also heal the hero Io and his Tethered targed try to gank.
Additional:
* Ensnare and Song of the Siren can be used to cancel both, Tether and Relocate and to close the distance on Io.
* Rip Tide combined with illusions from Mirror Image often finish off Io before he can save himself.
* Spirit's weak area-of-effect makes it a bad tool to deal with Naga Siren's illusions from Mirror Image.
* Once Naga Siren buys Aghanim's Scepter, she can gain access to Reel In, which not only allows her to cancel both, Tether and Relocate, but also to pull Io to herself and her team while he is affected with Ensnare, similarly to Batrider's Flaming Lasso.
* Aghanim's Shard upgraded Song of the Siren can also heal the hero Io and his tethered targed try to gank.
Axe
* Melee heroes who rely on summons, illusions, or clones will trigger Counter Helix more often, thus taking more damage: Meepo, Lycan, Phantom Lancer
Additional:
* Berserker's Call can keep Lycan in place during his Shapeshift even through Black King Bar.
* Counter Helix is very effective against Lycan because of his summons.
* Culling Blade will prevent Lycan from running away with Shapeshift when he drops low.
Naga Siren
* Lycan is a hero focused entirely on single target physical damage and lacks disables or AoE damage. Due to this, he will have difficulties dealing with illusions or Naga Siren's Ensnare.
Axe
* A well-timed Berserker's Call can expose Nyx Assassin while he is invisible with Vendetta, and prevent him from using Spiked Carapace.
* Axe can use Battle Hunger's damage over time to minimialize effects of Spiked Carapace.
* Axe's high health also allows him to easily shrug off Nyx Assassin's burst damage and fend him off. Especially since Axe is a common Heart of Tarrasque wielder, which can completely eliminate any chance for Nyx Assassin to kill Axe alone.
* Culling Blade can often kill Nyx Assassin as he is very fragile and vulnerable to damage while Spiked Carapace is on cooldown.
Additional:
* A well-timed Berserker's Call can expose Nyx Assassin while he is invisible with 
Vendetta, and prevent him from using 
Spiked Carapace.
* Axe can use Battle Hunger's damage over time to minimialize effects of Spiked Carapace.
* Axe's high health also allows him to easily shrug off Nyx Assassin's burst damage and fend him off. Especially since Axe is a common Heart of Tarrasque wielder, which can completely eliminate any chance for Nyx Assassin to kill Axe alone.
* Culling Blade can often kill Nyx Assassin as he is very fragile and vulnerable to damage while Spiked Carapace is on cooldown.
Naga Siren
* Nyx Assassin's skillset is mostly single-targeted, therefore he will have difficulties against heroes with illusions and summons: Naga Siren, Broodmother, Lycan, Visage, Phantom Lancer. And to make things worse, Nyx Asassin is not a common Battle Fury, 
Maelstrom, Mjollnir, Gleipnir or Radiance wielder to counter this problem.
Axe
* Ranged heroes that can easily harass Axe: Drow Ranger, Sniper, Lion.
Axe
* Axe can easily close the distance to Sniper with Blink Dagger.
* With Berserker's Call in combination with Counter Helix and Battle Hunger, Axe can make short work of Sniper, finishing him off easily with Culling Blade due to his low HP & high attack speed in the late game.
Naga Siren
* Ensnare with her attacks allows Naga Siren to gank Sniper easily.
* Rip Tide removes Sniper's very little armor.
Axe
* Heroes who can stop Axe from getting close will severely inhibit his presence in fights: Bristleback, Crystal Maiden, Batrider, Arc Warden, Winter Wyvern, Clockwerk
Axe
* Berserker's Call can interrupt Freezing Field, even through Black King Bar and/or 
Glimmer Cape.
* Battle Hunger makes Crystal Maiden's already bad movement speed even worse.
* Axe frequently builds Blade Mail, which can quickly kill Crystal Maiden if her ultimate is used while he is under its effect.
Naga Siren
* Mirror Image can dispel Frostbite. A similar effect can be achieved with Manta Style, a core item on Naga Siren.
* Song of the Siren can stop Freezing Field regardless of any kind of invisibility as well as allow Naga Siren's team to quickly close the gap on Crystal Maiden.
* With Aghanim's Scepter, Naga Siren can get access to Reel In ability, which can allow her to pull Crystal Maiden toward herself and her team and cancel Freezing Field even through Black King Bar.
Additional:
* Mirror Image can dispel Frostbite.
* Song of the Siren can stop Freezing Field regardless of any kind of invisibility as well as allow Naga Siren's team to quickly close the gap on Crystal Maiden.
* Ensnare allows Naga Siren and her team to quickly catch up with Crystal Maiden and kill her.
* With Aghanim's Scepter, Naga Siren can get access to Reel In ability , which can allow her to pull Crystal Maiden toward herself and her team and cancel Freezing Field even through Black King Bar.
Axe
* Heroes who can stop Axe from getting close will severely inhibit his presence in fights: Bristleback, Crystal Maiden, Batrider, Arc Warden, Winter Wyvern, Clockwerk
Axe
* Magnetic Field doesn't provide a protection against Berserker's Call and Counter Helix and his high attack speed together with Tempest Double will often trigger Counter Helix.
* The threat of a blink and Berserker's Call may make the real Arc Warden stay further back, thus effectively halving the team's damage output for a while.
Naga Siren
* Naga Siren's illusions from Mirror Image can depush the lanes pushed by the Tempest Double, relieving the pressure.
* Mirror Image can dispel Flux, and the illusions can stop Flux from working to it's full power.
Additional:
* Song of the Siren stops Arc Warden from acting and allows Naga Siren's team to close in on him, past his 
Magnetic Field.
* Mirror Image dispels 
Flux. The illusions created from it also disable the slow from Flux if Arc Warden casts it after Mirror Image.
* Arc Warden's playstyle heavily favors split-pushing, which Naga Siren can compete against with her illusions.
Axe
* Heroes with gap-closing abilities will be easy targets for Berserker's Call: Phantom Assassin, Faceless Void, Slark, Chaos Knight, Morphling, 
Queen of Pain
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.
Axe
* Heroes with gap-closing abilities will be easy targets for Berserker's Call: Phantom Assassin, Faceless Void, Slark, Chaos Knight, Morphling, Queen of Pain
Additional:
* Berserker's Call allows Axe to lock down Chaos Knight and his illusions even through Black King Bar.
* Counter Helix combined with Blade Mail clears illusions out in no time.
Naga Siren
* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother
Axe
* Berserker's Call catches Phantom Lancer when he is hidden among his illusions.
* Counter Helix quickly destroys Phantom Lancer's illusion army. The more illusions there are, the more often Counter Helix is triggered.
* Phantom Lancer's low early game health makes him an easy target for Culling Blade.
Additional:
* Berserker's Call helps locking down Phantom Lancer in a group of illusions.
* Counter Helix combined with Blade Mail clears Phantom Lancer's illusions quickly.
* Phantom Lancer's low health in the early game makes him a frequent target for Culling Blade.
Naga Siren
* Song of the Siren is very difficult for Rubick to 
Spell Steal when he is affected by sleep.
* Ensnare and Rip Tide together with some attacks can take Rubick down quickly, due to his low health pool and armor.
* Naga Siren usually buys Diffusal Blade, which may prevent Rubick from using his abilities.
* Mirror Image allows Naga Siren to dodge the incoming stun from 
Telekinesis (when she is not a target), and it can also dispel 
Fade Bolt's damage reduction debuff.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Axe
* Most of the Axe's abilities can affect Muerta during Pierce the Veil, except for Battle Hunger which deals physical damage.
* While Muerta can do much damage to highly armored units, Axe has a larger health pool compared to Muerta and can activate Berserker's Call and Blade Mail to turn Muerta's attack damage against her.
* Counter Helix takes advantage of Muerta's high attack speed from both stats and items.
Naga Siren
* Any long duration disables that can pierce through both, Pierce The Veil and Black King Bar are devastating against Muerta: Enigma's 
Black Hole, 
Dawnbreaker's Solar Guardian, Axe's Berserker's Call, Naga Siren's Aghanim's Scepter upgraded Ensnare and Reel In from Aghanim's Scepter, Jakiro's Aghanim's Scepter upgraded 
Macropyre, Bane's Fiend's Grip, Pudge's 
Dismember, Batrider's Flaming Lasso, Beastmaster's Primal Roar, 
Grimstroke's 
Soulbind, Medusa's Stone Gaze, Magnus's Reverse Polarity.
Naga Siren
* Dazzle can instantly destroy all of Naga Siren's illusions from Mirror Image with Aghanim's Shard upgraded 
Poison Touch used on her or any of her illusions.
Axe
* Culling Blade ignores the protection from 
Shallow Grave and will kill any target whose health is low enough. This makes Axe one of the hardest counters to Dazzle, and he neutralizes one of Dazzle's most important abilities.
Additional:
* Culling Blade kills any target under the health threshold, even through Shallow Grave.
Naga Siren
* Mirror Image's illusions can easily walk straight at Dazzle and attack him, due to Dazzle's lack of reliable AoE nukes or disables.
* Ensnare roots Dazzle or his allies, making it harder to stay in range of Dazzle's saving abilities.
* Song of the Siren can be used to initiate a fight with superior positioning, potentially zoning Dazzle's high-impact spells out of the fight.
Axe
* Berserker's Call is one of the best ways to lock down Weaver before he has a chance to use 
Time Lapse. It can also catch Weaver in 
Shukuchi.
* Weaver's high attack speed, along with high attack damage from 
Geminate Attack, triggers Counter Helix continuously and the output damage would be returned by Blade Mail.
Additional:
* Berserker's Call is one of the best ways to lock down Weaver before he has a chance to use Time Lapse. It can also catch Weaver in Shukuchi.
* Due to his fast attack speed from Geminate Attack and items that give attack speed, Counter Helix will activate a lot, and the damage would be returned by Blade Mail, which hurts Weaver far more than it hurts Axe.
* Culling Blade can finish off Weaver's low health pool before he escapes with Shukuchi and Time Lapse.
* Battle Hunger is a good tool to pop Weaver's Linken's Sphere due to its low cooldown.
Axe
* Berserker's Call forces Mars to face in the direction choosen.
* Counter Helix deals pure damage and can go through Bulwark.
Axe
* Berserker's Call prevents Anti-Mage from escaping with Blink, and works well with Blade Mail against Anti-Mage's relatively low health.
* Counter Helix often triggers even if Axe's depleted of mana, which will make Anti-Mage take more damage than he's dealing and deals pure damage, ignoring the protection from Counterspell.
* Axe's low mana pool makes him a bad target for using Mana Void.
* Axe's high base health regeneration allows him to dominate the lane against Anti-Mage, especially with a support.
Additional:
* Berserker's Call is one of the most reliable ways to lock down Anti-Mage, preventing him from 
Blinking away.
* Anti-Mage's high attack speed, along with illusions from Manta Style, triggers Counter Helix continuously.
* Axe's low mana pool and high health pool make 
Mana Void deal very little damage to Axe.
Axe
* Troll Warlord's high attack speed means Counter Helix will proc extremely frequently even without creeps near him. This, combined with a Blade Mail means Axe can easily solo kill Troll Warlord even in later stages of the game.
* 
Battle Trance does not save Troll Warlord from a Culling Blade.
Additional:
* Troll Warlord has significant attack speed due to Fervor and Battle Trance, giving Axe a higher chance to proc Counter Helix and seriously injure Troll Warlord due to his relatively low maximum health.
* Axe often purchases Blade Mail, which can help Axe turn Troll Warlord's farm and high physical damage against him. The bonus armor provided by Berserker's Call means that Troll Warlord will take a lot more damage than Axe.
* Culling Blade is still capable of killing Troll Warlord during Battle Trance if his HP is low enough.
Axe
* Berserker's Call forces Dark Willow to attack, cancelling Shadow Realm.
Axe
* Berserker's Call and Counter Helix allow Axe to kill Shadow Fiend if he stands too close to a creep wave.
* Battle Hunger is can be strong against Shadow Fiend in the early game because Shadow Fiend's low attack damage makes it hard for him to get last hits if he has no mana. However, Shadowraze also makes it very easy for him to get last hits, so use with caution.
* Axe's naturally high strength and health regeneration will be enough to tank a lot of Shadow Fiend's damage in the early game.
Axe
* Unleash ensures that Axe's Counter Helix procs many times, even if he is stunned by Dispose.
* Aghanim's Shard allows Counter Helix to reduce the attack damage of anyone it strikes. Combined with Unleash causing to proc frequently, Marci will not be dealing significant damage as she attacks Axe over time.
* Axe doesn't worry about the damage from Unleash if he activates Berserker's Call beforehand. If he had activated Blade Mail or Mjollnir (or even both) as Marci attacks him, he will turn Unleash's high attack speed and damage against her.
* Usually, Axe would prefer to jump on his opponent to be more effective. Rebound does Axe a favor, bringing Marci within his most effective range.
Axe
* Axe can force Alchemist to attack him with Berserker's Call. High attack speed from 
Chemical Rage will cause Counter Helix to proc multiple times.
* This can get worse if axe has Blade Mail, which then returns all damage to Alchemist himself.
* Axe's abilities can pierce through Black King Bar, which is a common item for Alchemist.
* Berserker's Call grants Axe a huge bonus armor, which greatly counters Alchemist's physical damage for the most part.
Naga Siren
* Unless Lone Druid purchases a Black King Bar for his Spirit Bear, Ensnare will easily kite the Spirit Bear.
* Song of the Siren allows Naga Siren and her team to completely bypass the Spirit Bear and hunt for the Lone Druid himself when starting a fight.
* Lone Druid's lack of innate AoE capabilities mean that Naga Siren's illusions have no problem against him.
Axe
* Berserker's Call can catch Broodmother in her web, as well as groups of spiderlings. This is particularly effective when Broodmother attempts to push towers with her spiderlings.
* Counter Helix destroys spiderlings very quickly and earns Axe a good deal of gold.
Additional:
* Berserker's Call forces Broodmother and her spiderlings to attack, allowing for large amounts of pure damage to be done through Counter Helix.
Axe
* False Promise will not save an ally from Culling Blade if their health is low enough.
* Fate's Edict, offensively or defensively, does little to protect Oracle's allies from the majority of Axe's damage.
Axe
* Axe can Berserker's Call into a flock of Familiars, proccing Counter Helix and killing them off.
* Familiars' very fast attacks will proc Counter Helix, receiving full damage due to their low attack range.
Naga Siren
* Heroes with summons like Broodmother, Enigma, Nature's Prophet; or illusions, like Naga Siren, Terrorblade are effective at keeping the choke points and rune spawns safe from Proximity Mines.
Axe
* Heroes that can keep Monkey King stunned for a long time can pose a threat: Axe, Centaur Warrunner.
Axe
* Durable heroes can stand against Tusk during 1v1: Axe, Dragon Knight, 
Night Stalker, Centaur Warrunner, Wraith King and more.
Axe
* Axe, Bristleback, Centaur Warrunner, Spirit Breaker, Pudge, 
Huskar, Wraith King, 
Doom: These heroes are too tanky for Puck to burst down. Also, all of them have spells which can deal with and shut Puck down reliably.
Axe
* Heroes with gap-closing abilities will be easy targets for Berserker's Call: Phantom Assassin, Faceless Void, Slark, Chaos Knight, Morphling, Queen of Pain
Additional:
* Berserker's Call prevents Queen of Pain from escaping with Blink and also pierces her Black King Bar.
* Due to her fast attack speed from Mjollnir, it will quickly trigger Counter Helix.
* Culling Blade finishes off Queen of Pain's low health pool before she gets a chance to escape, preventing her from playing the hit-and-run style often associated with Queen of Pain.
Naga Siren
* Illusion heroes like the aforementioned Phantom Lancer or Naga Siren, or heroes that tend to buy Manta Style, like Luna or Juggernaut, will give Slardar a hard time, as his damage is single-targeted.
Naga Siren
* Heroes who are illusion based, or even heroes who frequently build Manta Style can be cleared quickly by Pangolier's high damage, or lose their damage ouput because of Lucky Shot: Chaos Knight, Naga Siren
Axe
* Heroes with other kind of disables that pierce spell immunity can hold Pangolier in place during Rolling Thunder: Axe, Beastmaster, Enigma, Magnus, Pudge, Batrider, Bane, Winter Wyvern
Naga Siren
* Heroes with powerful rooting abilities will disable most of Pangolier's skills, a bonus point if it pierces spell immunity since it will also be able to stop Pangolier during his Rolling Thunder: 
Treant Protector, Meepo, Crystal Maiden, 
Dark Willow, Underlord, Naga Siren
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.
Naga Siren
* Naga Siren with Mirror Image
* Heroes that can dodge Glimpse:
* Puck with 
Phase Shift
* Riki with 
Tricks of the Trade
* Phantom Lancer with 
Doppelganger
* 
Ember Spirit with 
Sleight of Fist and 
Activate Fire Remnant
* Chaos Knight with 
Phantasm
* Naga Siren with Mirror Image
* 
Tusk with 
Snowball
* Juggernaut with 
Omnislash
* 
Brewmaster with 
Primal Split
* 
Lifestealer with 
Infest
* Phoenix with Supernova
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
Axe
* Heroes who can continue dealing damage even while being stunned: Luna, 
Razor, Axe, Bristleback, Leshrac, Death Prophet, Jakiro.
Naga Siren
* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, 
Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.
Naga Siren
* Illusion heroes, such as Naga Siren, Phantom Lancer, Chaos Knight, Terrorblade will become strong against Tinker in the late game. Without Aghanim's Scepter Tinker is forced to defensively disarm heroes with Laser, leaving illusions free to deal physical damage which Tinker's low armor makes highly effective. In addition, Mjollnir or Battle Fury, two common pickups against illusion heroes, don't work well on Tinker at all.
Naga Siren
* Heroes with summons and illusions such as Broodmother and Naga Siren, are ill-suited for Wraith King to fight, as he has no source of waveclear.
Axe
* Heroes with burst damage of their own won't be afraid to go toe to toe with Void Spirit, like 
Ursa, Lifestealer, or Axe.
Naga Siren
* Heroes with illusions and summons can swarm and overwhelm Bane, who has no area abilities to deal with them outside from Aghanim's Shard upgraded 
Brain Sap: Broodmother, Chaos Knight, Naga Siren, Nature's Prophet, Phantom Lancer, Terrorblade, Visage, Warlock, Wraith King.
Axe
* Pudge, Legion Commander and Axe will make the match a living hell for Shadow Shaman, since they are known for surprise attacks from the fog and quickly killing low HP heroes. They can also interrupt Shadow Shaman's channeling, Legion being especially problematic, as she can use 
Press the Attack on an ally who is hexed as well.
Naga Siren
* Naga Siren with Mirror Image
* Heroes that can remove the Track debuff with their skills:
* 
Abaddon with Aphotic Shield and Borrowed Time
* Huskar with 
Life Break
* Juggernaut with 
Blade Fury
* Legion Commander with Press the Attack
* Lifestealer with Rage and Infest
* Naga Siren with Mirror Image
* 
Omniknight with 
Heavenly Grace
* 
Oracle with 
Fortune's End and 
False Promise
* Phantom Lancer with Doppelganger
* Slark with Dark Pact
* Ursa with Enrage
* 
Weaver with Time Lapse
* 
Tidehunter with 
Kraken Shell when damage received reaches the threshold.
Additional:
* Bounty Hunter is a single target damage dealer, so he will not fare well against Naga Siren. Even though Bounty Hunter can use 
Track on her, Mirror Image will dispel the effect. Ensnare also reveals invisible units while they're rooted, putting Bounty Hunter at a disadvantage.
Naga Siren
* As long as Windranger is able to identify the real hero among the illusions, heroes relying on them can be easily tagged with Focus Fire: Chaos Knight, Terrorblade, Phantom Lancer, Naga Siren.
Axe
* 
Windrun does not provide protection against Counter Helix and Berserker's Call. Her fast attack speed with Focus Fire will also quickly trigger Counter Helix multiple times.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Axe
* Berserker's Call prevents Sven from bursting his targets before Axe can interfere. The worst kind of opponent for Sven is one who can stop him from attacking who he wants to, which is exactly what Axe does.
* Culling Blade may finish off Sven before he has the chance to lifesteal or run with Warcry.
* Axe is a very common Blade Mail carrier which will make very short work of a Sven with God's Strength activated.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Naga Siren
* Ensnare disables Templar Assassin's invisibility and Blink Dagger (a core item on Templar Assassin), and her illusions will break 
Refraction easily.
Axe
* Ranged heroes that can easily harass Axe: Drow Ranger, Sniper, Lion.
Axe
* Berserker's Call forces Drow Ranger to attack Axe up close, disabling her Marksmanship bonus.
* Counter Helix occurs more often with Drow Ranger's high attack speed.
* Culling Blade is a dangerous ability against a low health hero like Drow Ranger.
Naga Siren
* 
Atrophy Aura makes it hard or Naga Siren to farm on lane and damage Underlord with Rip Tide in teamfights. And her only way to counter this is by playing Nuker role.
* Firestorm is very useful for clearing Naga Siren's illusions from Mirror Image and Manta Style.
* However, Naga Siren can catch Underlord and his team unprepared with Song of the Siren if he chooses to use 
Fiend's Gate to get to a designated point of the map. Naga Siren can also prevent escaping with Fiend's Gate with Ensnare and Reel In from Aghanim's Scepter.
Additional:
* Atrophy Aura makes it hard or Naga Siren to farm on lane and damage Underlord with Rip Tide in teamfights. And her only way to counter this is by playing Nuker role.
* Firestorm is very useful for clearing Naga Siren's illusions from Mirror Image and Manta Style.
* However, Naga Siren can catch Underlord and his team unprepared with Song of the Siren if he chooses to use Fiend's Gate to get to a designated point of the map. Naga Siren can also prevent escaping with Fiend's Gate with Ensnare and Reel In from Aghanim's Scepter.
Axe
* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: Luna's Aghanim's Scepter upgraded Eclipse, Dawnbreaker's Solar Guardian, Axe's Berserker's Call, Mars's 
Arena of Blood, Jakiro's Macropyre, Dual Breath and Ice Path, Naga Siren's Song of the Siren, Razor's 
Eye of the Storm and 
Plasma Field, Lina's 
Light Strike Array, Broodmother's 
Spinner's Snare from Aghanim's Scepter, Elder Titan's Earth Splitter and 
Echo Stomp, 
Alchemist's 
Unstable Concoction and 
Acid Spray, Queen of Pain's 
Sonic Wave, 
Dark Seer's 
Wall of Replica and 
Vacuum, 
Venomancer's 
Noxious Plague and 
Poison Nova from Aghanim's Scepter, Oracle's Fortune's End and 
Rain of Destiny from Aghanim's Shard, Bloodseeker's 
Blood Rite, Enigma's Black Hole and Midnight Pulse, 
Shadow Fiend's 
Requiem of Souls, Batrider's Aghanim's Scepter upgraded Flaming Lasso, Firefly, Flamebreak and Sticky Napalm, 
Ancient Apparition's 
Ice Blast, Sand King's 
Epicenter, 
Sand Storm and 
Burrowstrike, Gyrocopter's Call Down, Ember Spirit's Sleight of Fist, Death Prophet's 
Exorcism and 
Silence, 
Monkey King's 
Wukong's Command, Crystal Maiden's 
Freezing Field, Muerta's 
The Calling, Medusa's Stone Gaze, Zeus's 
Nimbus from Aghanim's Scepter. Dark Willow's 
Bramble Maze, 
Pangolier's 
Swashbuckle, Grimstroke's Soulbind, 
Ink Swell and 
Stroke of Fate, Earthshaker's Echo Slam and 
Fissure, Puck's 
Dream Coil and 
Waning Rift, Winter Wyvern's 
Winter's Curse, Magnus's Reverse Polarity.
Naga Siren
* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: Luna's Aghanim's Scepter upgraded Eclipse, Dawnbreaker's Solar Guardian, Axe's Berserker's Call, Mars's Arena of Blood, Jakiro's Macropyre, Dual Breath and Ice Path, Naga Siren's Song of the Siren, Razor's Eye of the Storm and Plasma Field, Lina's Light Strike Array, Broodmother's Spinner's Snare from Aghanim's Scepter, Elder Titan's Earth Splitter and Echo Stomp, Alchemist's Unstable Concoction and Acid Spray, Queen of Pain's Sonic Wave, Dark Seer's Wall of Replica and Vacuum, Venomancer's Noxious Plague and Poison Nova from Aghanim's Scepter, Oracle's Fortune's End and Rain of Destiny from Aghanim's Shard, Bloodseeker's Blood Rite, Enigma's Black Hole and Midnight Pulse, Shadow Fiend's Requiem of Souls, Batrider's Aghanim's Scepter upgraded Flaming Lasso, Firefly, Flamebreak and Sticky Napalm, Ancient Apparition's Ice Blast, Sand King's Epicenter, Sand Storm and Burrowstrike, Gyrocopter's Call Down, Ember Spirit's Sleight of Fist, Death Prophet's Exorcism and Silence, Monkey King's Wukong's Command, Crystal Maiden's Freezing Field, Muerta's The Calling, Medusa's Stone Gaze, Zeus's Nimbus from Aghanim's Scepter. Dark Willow's Bramble Maze, Pangolier's Swashbuckle, Grimstroke's Soulbind, Ink Swell and Stroke of Fate, Earthshaker's Echo Slam and Fissure, Puck's Dream Coil and Waning Rift, Winter Wyvern's Winter's Curse, Magnus's Reverse Polarity.
Naga Siren
* Blade Fury offers good AoE damage to clear illusions and can hurt the real Naga Siren as well if she chooses to blend in the illusions. Diffusal Blade does nothing to Juggernaut either when he uses Blade Fury.
* Aghanim's Shard upgraded Blade Fury along with Lv 20 DPS talent will shred all illusions almost instantly, especially when combined with Mjollnir, a common item for Juggernaut.
Axe
* Heroes who rely on fast attack speed will also trigger Counter Helix frequently: Faceless Void, 
Troll Warlord, Anti-Mage, Juggernaut, Arc Warden, Morphling
Additional:
* Berserker's Call pierces spell immunity, making a Blade Fury teleport escape impossible. It's very useful against Omnislash as well.
* Juggernaut's low base health and high attack speed causes him to take a lot of damage from Counter Helix.
* Axe is a common Blade Mail and Blink Dagger carrier making him a very big potential threat before Juggernaut get his items.
Naga Siren
* Illusion-based heroes are effective against Omnislash and Juggernaut's single-targeted damage: Naga Siren, Chaos Knight, Terrorblade,Phantom Lancer.
Axe
* Heroes who can stop Axe from getting close will severely inhibit his presence in fights: Bristleback, Crystal Maiden, Batrider, Arc Warden, Winter Wyvern, Clockwerk
Axe
* Axe forces Bristleback to turn around with Berserker's Call, allowing allies to attack him without fear of his passive.
Naga Siren
* 
Waveform clear Mirror Image illusions from Naga Siren. And though Ensnare can prevent Morphling from using Waveform to escape, he can easily dispel it with Manta Style, a common item on Morphling.
* 
Morph allows Morphling to copy Naga Siren's abilities and combine them with Manta Style, a commong item for Morphling, to destroy Naga Siren's illusions. Aghanim's Scepter upgraded Morph also allows Morphling to create a strong illusion of Naga Siren that can do the same and which can also allow Morphling to close the gap on Naga Siren.
Axe
* Jumping on Axe with Waveform will make Morphling an easy target for a counter-initiation with Berserker's Call.
* Morphling is often played at low health to maximize the bonuses from 
Attribute Shift (Agility Gain), and also because his abilities cost health to use. This makes him especially vulnerable to Culling Blade.
* However, Morphling is a common Linken's Sphere carrier to block Culling Blade, which may force Axe to use Battle Hunger to pop the Spell Block first.
* Attribute Shift (Agility Gain) gives Morphling no protection against the pure damage of Culling Blade. Its attack speed bonus also means that Counter Helix will proc more often.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Naga Siren
* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: Sven, Omniknight, Enigma, Luna, Naga Siren, Mars, Jakiro, Venomancer, Elder Titan, Faceless Void, 
Rubick, Keeper of the Light, 
Pugna, 
Invoker, Spectre, Alchemist, Treant Protector, Lina, Oracle, Zeus, Shadow Shaman, Phoenix, Razor, Huskar, Batrider, 
Kunkka, Tidehunter, Wraith King, Sand King, Medusa, Dawnbreaker.
Axe
* 
Poison Attack and 
Viper Strike slows Axe significantly, and puts his Blink Dagger on cooldown, preventing him from initiating. Viper Strike can also break from Counter Helix.
Additional:
* Viper Strike prevents Counter Helix from triggering, which significantly lowers Axe's damage output in the early to mid game.
* Viper's various slows and damage over time prevents Axe from initiating as well as putting his Blink Dagger on cooldown.
Naga Siren
* Naga Siren can easily disjoint, and dispel 
Corrosive Skin with Mirror Image.
* Since Viper is mostly a single-target hero, he will not have almost any chance against Naga Siren because she is an illusion based hero.
* Viper has no burst damage, so Naga Siren will have plenty of time to use Aghanim's Shard upgraded Song of the Siren heal her allies before Viper can finish them off.
Axe
* Omniknight's healing prevents allies from dropping low enough for Culling Blade
* Heavenly Grace dispels Battle Hunger.
* Axe also tends to get close to allied heroes in order to damage them with his Counter Helix, which can easily be punished by Purification.
Naga Siren
* Even though Naga Siren relies on direct attacks to deal damage for most of the time, Song of the Siren allows her to easily waste 
Guardian Angel.
* Ensnare fully works on targets affected with Heavenly Grace. However, Ensnare is dispellable with any dispel, and so can be dispelled by Heavenly Grace.
* As an agility hero that relies on illusions, Naga Siren is one of the most natural Diffusal Blade carriers, the bane of every hero with a small mana pool. Naga Siren can also buy items that deal magical damage like Radiance, 
Dagon, 
Ethereal Blade, 
Revenant's Brooch, 
Veil of Discord and Gleipnir to attack Omniknight's allies protected with Guardian Angel.
Additional:
* Although Naga Siren relies mostly on physical damage, Song of the Siren can be used to time out Guardian Angel, giving Naga Siren's team an easy opportunity to counter-initiate.
* Radiance allows it's owner to deal magical damage to multiple enemy heroes at once, and since Naga Siren often buys it, Guardian Angel is not a very good ability for protection against Naga Siren.
* Likewise, Nuker build Naga Siren (which primarly consists of items such as Radiance, Ethereal Blade, Dagon and Veil of Discord) can render Guardian Angel useless. Although Nuker is not a role Naga Siren should be playing.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
Axe
* Heroes with high armor and durability can be exceptionally hard for Bloodseeker to bring down: Dragon Knight, Axe
Naga Siren
* Naga Siren's Song of the Siren may be useful but Poof will destroy all of her illusions.
Axe
* Melee heroes who rely on summons, illusions, or clones will trigger Counter Helix more often, thus taking more damage: Meepo, Lycan, Phantom Lancer
Additional:
* The combination of Counter Helix and Berserker's Call can disable multiple Meepos and deal heavy area damage.
* Axe's natural high survivability makes it difficult to burst him down with Poof or chip away at his health with Ransack.
Axe
* 
Crippling Fear makes it so Axe might use Blink Dagger right into an AoE silence in the middle of everyone.
* 
Void cripples Axe's already bad movement speed and attack speed.
* 
Hunter in the Night makes it impossible for Axe to catch up to fleeing or escape from Night Stalker during the night.
* Lastly, 
Dark Ascension gives full vision over Axe before he initiates, making the opponents all recognize his location immediately and allowing Night Stalker to prevent it or vocally tell his team if needed.
* Night Stalker has very high strength gain, even in the lane, so a successful Culling Blade is very unlikely.
* Axe's Blade Mail will likely do nothing to Night Stalker because of his high health and certain requirements for him to do the most damage to be true.
Naga Siren
* Mirror Image can be effective since Night Stalker cannot withstand fighting illusions. If he's unable to tell which Naga Siren is real, he will have a hard time landing his Void. However, if Night Stalker obtains an Aghanim's Scepter, the upgraded Void will hit and may even locate the real Naga Siren in fights.
Additional:
* Ensnare and Song of the Siren prevents Night Stalker from escaping and ganking during daytime or even nighttime.
* Rip Tide reduces Night Stalker's armor, making him easier to focus down.
* Mirror Image can be effective against Night Stalker, due to his single target abilities.
Axe
* Outworld Destroyer's pure and magical damage is particularly effective against Axe.
Astral Imprisonment is an excellent way to defend against an initiating Axe.
Sanity's Eclipse deals high damage to Axe due to his low mana pool.
Berserker's Call bonus armor doesn't block Arcane Orb's pure damage.
*
*
Additional:
*
* Astral Imprisonment can be used to prevent an ally or Outworld Destroyer himself from an Axe initiation.
* Axe's low mana means he's susceptible to a powerful Sanity's Eclipse.
Naga Siren
*
Arcane Orb allows Outworld Destroyer's attacks to deal pure damage that can bypass Naga Siren's armor, and which can clear her illusions in no time.
Astral Imprisonment can be used to harass Naga Siren by reducing her maximum mana and to prevent Naga Siren from escaping with Song of the Siren. Outworld Destroyer can also use 
Astral Imprisonment to protect himself from Naga Siren.
Sanity's Eclipse will most likely instantly kill Naga Siren along with her illusions. Even if Naga Siren survives 
Sanity's Eclipse, it's mana allergy debuff will discourage Naga Siren from using her abilities as the mana allergy will heal Outworld Destroyer if she uses them for it's duration.
*
*