Zeus
* Zeus laneing against Ember is going to be punished with Sleight of Fist due to his low health pool
* Zeus's chip damage from 
Arc Lightning and other spells is nullified from Ember's Flame Guard.
Additional:
* Ember Spirit has a built-in antimagic shield, and Zeus has nothing but this magical damage, because of this, their confrontation on the center line can turn out to be sad for Zeus. If on such a line Ember Spirit will finish off all creeps under its 
Flame Guard, and Zeus with the help of Arc Lightning, then eventually Zeus will lose mana faster, and will be forced to look for ways to replenish it
* Ember Spirit can interrupt Zeus with his "jumping" abilities, the fact is that Zeus deals damage from his abilities directly, while Ember Spirit disappears for milliseconds from the battlefield when flying during the 
Sleight of Fist action or when flying into 
Fire Remnant
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.
Zeus
* Heroes with summons that are destroyed by a fixed number of attacks: 
Undying's 
Tombstone, 
Gyrocopter's 
Homing Missile, and 
Zeus's 
Nimbus.
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.
Zeus
* None of Zeus's abilities can damage a Juggernaut in 
Blade Fury.
* Zeus's short attack range makes it difficult for him to target a well-placed 
Healing Ward. His frequent use of Arc Lightning will have almost no effect on allies being healed by Juggernaut.
* Zeus has no way to defend himself, even if Juggernaut cannot use Blade Fury. He can be easily taken out if cornered, sometimes even without 
Omnislash.
Additional:
* Blade Fury negates all magical damage from Zeus.
* Omnislash can easily take down Zeus. However, be aware that most players will get a 
Eul's Scepter of Divinity or a 
Ghost Scepter against Juggernaut.
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.
Naga Siren
* Illusion-based heroes are effective against Omnislash and Juggernaut's single-targeted damage: Naga Siren, 
Chaos Knight, Terrorblade,Phantom Lancer.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as 
Clockwerk, 
Kunkka, 
Puck, 
Skywrath Mage, 
Spirit Breaker, 
Tusk and others.
Naga Siren
* Heroes with long cast animations can be continuously interrupted by Battery Assault: 
Centaur Warrunner, 
Jakiro, 
Leshrac, Naga Siren, 
Underlord.
Zeus
* As a spellcaster, silences will nullify him entirely. Some notable examples are 
Death Prophet, 
Drow Ranger, 
Bloodseeker, 
Disruptor and many others.
* 
Doom, as usual, fits this description nicely.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, 
Witch Doctor.
Zeus
* Heroes who cannot prevent Sven from killing supports will always be at a disadvantage in fights such as 
Lina, 
Slark and Zeus.
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
* 
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.
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.
Zeus
* Zeus' main source of damage is his low cooldown, high damage spells - meaning Last Word and Global Silence will pretty much take him out of the game for the duration.
* Zeus likes to spam his abilities, which makes him vulnerable to Arcane Curse.
* If Zeus dies near Silencer, he will begin to lose intelligence, reducing his mana pool, mana regen, and attack damage. Furthermore, if the game is long and Zeus dies often, the intelligence losses will also reduce his spell damage.
Additional:
* Silencer's 
Global Silence will render Zeus useless for 6 seconds in a team fight.
* 
Arcane Curse will punish Zeus for casting spells, which can cause continuous damage to him should he continue to cast spells.
* 
Last Word can silence Zeus and prevent him from spamming his spells.
* Silencer often builds 
Orchid Malevolence (or 
Bloodthorn) which can be used on spell casters like Zeus, forcing him to invest in a 
Linken's Sphere.
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.
Zeus
* Zeus almost exclusively relies on magical damage, which is heavily reduced by Counterspell.
* Zeus' complete lack of mobility makes him very easy for Anti-Mage to chase down with Blink.
* Zeus likes to stand in the back during team fights, but Anti-Mage can easily Blink to close the distance.
Additional:
* Anti-Mage can burn mana, which is a big problem for a spellcaster like Zeus that heavily relies on it.
* 
Counterspell decreases magical damage taken from Zeus.
* Zeus' high intelligence and mana pool makes him a perfect target for 
Mana Void.
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.
Zeus
* Heroes with a lot of burst damage, especially those who rely on casting spells: Lina, Zeus.
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.
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.
Zeus
* 
Enrage will make it very difficult to burst him down.
* Zeus has little armor, HP and mobility; Ursa's favorite kind of target.
Naga Siren
* Axe will destroy her illusions by proccing 
Counter Helix more often due to him being hit by more attacks.
Zeus
* Even though Pugna's low HP means that he can be quickly burst down, his 
Nether Ward heavily punishes casters whose spells cost a lot of mana, like Zeus. Casting 4 of his active spells, including Nimbus, close to an enhanced level 4 Nether Ward, can make the ward deal up to 1750 magical damage.
* 
Decrepify can further increase the damage dealt by Nether Ward upon Zeus. However, if used on Pugna himself or on one of his allies, it will amplify the damage done by Zeus' abilities.
Zeus
* Zeus likes to stay far back in fights, dealing his damage uninterrupted, but once he gets hooked into the fight, he usually dies very quickly.
* Pudge's high strength from Flesh Heap makes it very hard for Zeus to burst him down.
* Zeus' low health pool makes him very vulnerable to the damage from Meat Hook, Rot and Dismember.
Additional:
* 
Meat Hook's high range allows Pudge's team to drag Zeus in the middle of the fight and abuse his frailty.
* 
Flesh Heap's health and magic resistance bonus makes Pudge exceptionally resistant to Zeus' nukes. In later stages of the game, Zeus is usually unable to seriously damage Pudge at all. Even Static Field, which deals damage based on a percentage of the enemy's health, won't be doing much.
* Even if Zeus buys a Black King Bar, Meat Hook and 
Dismember still disable him for a long time, usually causing Zeus' quick death.
* Zeus is vulnerable to early ganks, which Pudge excels at.
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.
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.
Zeus
* Marci on the midlane will win the laning phase against Zeus almost every time, as her powerspike at level 6 will decimate Zeus' low health pool and force him to stay far back.
* Even before level 6, Dispose and Sidekick can easily take half of Zeus' health if he is in range of Dispose.
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.
Zeus
* Visage can quickly kill heroes with low to medium base armor and no innate escape mechanism. Examples include 
Alchemist, 
Crystal Maiden and 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.
Zeus
* As a spellcaster, silences will nullify him entirely. Some notable examples are Death Prophet, Drow Ranger, Bloodseeker, Disruptor and many others.
* Doom, as usual, fits this description nicely.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
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.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
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).
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.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
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.
Zeus
* Spirit Siphon does a lot of magical damage, especially in the early game. This allows her to demolish low health heroes such as Zeus, 
Pugna, especially when combined with her other spells.
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
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
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.
Zeus
* Zeus burst damage can be reduced by 
Dispersion and reflect some of the damage back to Zeus himself.
* Zeus has low mobility and stays in backlines, 
Spectral Dagger or 
Haunt can easily catch him as he has no escape mechanism.
* Since Zeus has low HP, Spectral Dagger and 
Desolate will quickly tear Zeus down when he's alone.
Zeus
* Zeus is good against heroes that juke in trees or up cliffs, like 
Batrider, 
Monkey King, Spectre, and 
Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Naga Siren
* 
Flak Cannon and 
Call Down can easily clear Naga Siren's illusions.
Zeus
* Heroes with high magical burst damage will kill Gyrocopter before he gets to do much: Lina, Lion, Zeus
Zeus
* 
Time Dilation can limit Zeus to casting his abilities only once in a fight, effectively serving as a 6/8/10/12 second silence.
* 
Time Walk negates Zeus's burst damage.
* 
Chronosphere makes Zeus the best target for Void because of his low mobility.
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.
Zeus
* Chaos Knight's high health pool makes him resistant to Zeus' burst damage. 
Phantasm can dispel 
Veil of Discord, a typical item purchased by Zeus.
* Zeus is easily overwhelmed by Chaos Knight's strong illusions, as Arc Lightning is not enough to kill them fast enough to have any impact.
* Zeus' low base armor makes him extremely vulnerable to Chaos Knight's high damage output and armor reduction.
Naga Siren
* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother
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.
Zeus
* Zeus is good against heroes that juke in trees or up cliffs, like Batrider, Monkey King, Spectre, and Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Zeus
* Arc Lightning and 
Lightning Bolt can easily burst Terrorblade and his illusions.
* 
Static Field from Aghanim's Shard can automatically hit everything in a big radius, taking a huge chunk of health out of Terrorblade's illusions, regardless of how much health they have.
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.
Zeus
* Heroes who can provide True Sight or semi-reveal enemy heroes as Nature's Prophet is prone to buying 
Shadow Blade: 
Bounty Hunter, 
Slardar, Spectre, Zeus, Spirit Breaker.
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.
Zeus
* Zeus's Lightning Bolt and 
Thundergod's Wrath provides a short duration of True Sight, revealing Riki while possibly dealing a heavy amount of damage.
* Zeus's Nimbus can be placed directly on top of 
Tricks of the Trade, potentially causing him to be damaged, stunned, and revealed the instant he becomes targetable again.
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.
Zeus
* Necrophos' 
Ghost Shroud increases the magic damage taken by Necrophos.
* If Zeus builds both an 
Ethereal Blade and Veil of Discord, it almost always guarantees a kill.
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.
Zeus
* Slardar has high priority on building moblity items such as 
Blink Dagger rather than tank items. Zeus can easily deal large amount of damage to him if not caught out of position first.
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.
Zeus
* Lightning Bolt makes roaming behind enemy lines more and more difficult as Zeus becomes powerful enough to spam it. Also, Zeus' Ultimate Thundergod's Wrath reveals Bounty Hunter regardless of his position.
Additional:
* Bounty Hunter has a very low health pool, allowing Zeus to burst him down quickly.
* Zeus can cast Lightning Bolt to gain True Sight in any area he suspects Bounty Hunter may be invisible or any area he thinks Bounty Hunter may have warded.
* If Bounty Hunter tries to escape a gank by using 
Shadow Walk, Zeus can gain vision of him with both Lightning Bolt and Thundergod's Wrath.
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.
Zeus
* Zeus can easily reveal Tinker's location in the trees with Thundergod's wrath.
* When Zeus has an Aghanim's Scepter, he can use his Nimbus, together with Lightning Bolt to interrupt Tinker's 
Keen Conveyance channelling and cancel Tinker's Blink Dagger.
Additional:
* Due to Tinker's low health pool, Zeus can easily burst Tinker down, while also cancelling 
Rearm.
* Once Zeus gets Aghanim's Scepter, he will gain Nimbus, which allows him to scout out Tinker on the map, especially when he is pushing lanes while hiding in the trees.
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
* 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.
Zeus
* Enchantress has a very low health pool, allowing Zeus to burst her down quickly before she can heal off the damage with Nature's Attendants.
* Zeus will not be affected by Untouchable, as he won't try to attack her with right clicks anyway.
* Zeus can stay out of her attack range while trying to kill her, especially if he has bought an 
Aether Lens.
* Most heroes would want to get on top of Zeus to kill him, but Enchantress does not have this option as doing so would severely limit her damage from Impetus.
* The exception is the laning phase, where Enchantress can gank Zeus if she Enchants a good creep.
Additional:
* Enchantress has a very low health pool, allowing Zeus to burst her down quickly before she can heal off the damage.
* Zeus will not be affected by 
Untouchable, as he won't try to attack her with right clicks anyway.
* Zeus can stay out of her attack range while trying to kill her, especially if he has bought an Aether Lens.
* Most heroes would want to get on top of Zeus to kill him, but Enchantress does not have this option as doing so would severely limit her 
Impetus damage.
* The exception is the laning phase, where Enchantress can gank Zeus if she Enchants a good creep.
Zeus
* Due to Hoodwink's low health and Zeus's high magic damage from Arc Lightning, Lightning Bolt and Static Field as well as global abilities from Thundergod's Wrath and Nimbus, he can easily kill her throughout the game and also reveal where Hoodwink is positioned or when she's in trees.
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.
Zeus
* Zeus's enormous magical damage output makes Pierce the Veil risky to use without a Black King Bar.
* Zeus does not rely on attack speed, making 
The Calling nearly pointless against him.
* If Zeus is ever too close to Muerta, he can use 
Heavenly Jump to disengage.
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.
Zeus
* Mars' own father is a formidable foe because Zeus deals massive amounts of magical damage. The high damage, low cooldown nukes of Arc Lightning and Lightning Bolt combined with the percent health magic damage of Static Field will shred Mars' health because it bypasses Bulwark completely.
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.
Zeus
* Zeus can easily find Magnus who is often hiding in the trees with Thundergod's Wrath and Lightning Bolt, which allows him to warn allies and disrupt his initiation attempts.
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.
Zeus
* Arc Lightning allows Zeus to get farm in lane against Shadow Fiend without coming into the range of his Shadowrazes.
* Lightning Bolt can be used to heavily harass Shadow Fiend when he tries to get a last hit.
* Thundergod's Wrath and Lightning Bolt can be used to detect Shadow Fiend if he tries to escape with Shadow 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
* Ensnare with her attacks allows Naga Siren to gank Sniper easily.
* Rip Tide removes Sniper's very little armor.
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.
Zeus
* Arc Lightning has a low cooldown can used to pop his Linken's Sphere.
* Lightning Bolt or (Nimbus upgraded from Aghanim's Scepter) detects Weaver during Shukuchi, preventing his ganks.
* Thundergod's Wrath can kill Weaver quickly before he can cast his Time Lapse at low health.
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.
Zeus
* Lich does not pose a big threat to Zeus in teamfights, as his spells don't have great cast range and Zeus should be too far back for a 
Chain Frost to bounce among him and his allies.
* Lich has a low health pool, allowing Zeus to burst him down quickly.
Zeus
* Zeus can reveal Clinkz with Lightning Bolt.
* He is vulnerable to Zeus's magical nukes, due to his low health pool.
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.
Naga Siren
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, Chaos Knight, Terrorblade, Naga Siren
Zeus
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: Nature's Prophet, 
Ancient Apparition, Zeus, Invoker, Treant Protector
Naga Siren
* Song of the Siren lasts long enough to prevent a successful 
Duel (but only if Naga wasn't the target).
Zeus
* Zeus greatly hinders Invoker on the line with his long-range abilities. QW- and QE-Invoker have a very long recharge on abilities, and Zeus' Arc Lightning ability recharges too quickly, which is why he quickly kills a pack of creeps and drives Invoker under his tower, punching and not letting finish off creeps
* Lightning Bolt and Thundergod's Wrath abilities reveal invisibility of enemies, for example Invoker invisibility from 
Ghost Walk ability
Additional:
* Zeus greatly hinders Invoker on the line with his long-range abilities. QW- and QE-Invoker have a very long recharge on abilities, and Zeus' Arc Lightning ability recharges too quickly, which is why he quickly kills a pack of creeps and drives Invoker under his tower, punching and not letting finish off creeps
* Lightning Bolt and Thundergod's Wrath abilities reveal invisibility of enemies, for example Invoker invisibility from Ghost Walk ability
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
* 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.
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.
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
* 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.
Zeus
* Heroes with global nukes will target and hit Phantom Lancer regardless of his illusions: Zeus
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.
Zeus
* Zeus's highly damaging nuke spells with low cooldowns is not something Luna can go against, though Luna can win against Zeus in late game.
* Thundergod's Wrath can be used before a fight to harm Luna before she activates Black King Bar, reducing her survivability for that fight.
* For the same reasons, Zeus makes a very powerful ally for Luna when they are in the same team.
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.
Zeus
* Zeus is good against heroes that juke in trees or up cliffs, like Batrider, Monkey King, Spectre, and Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Zeus
* Heroes with mediocre health pools who rely on armor or evasion to survive fights such as 
Troll Warlord, 
Windranger, and Terrorblade can be killed by Zeus if caught off guard.
Zeus
* Zeus can deal a huge amount of damage, but he lacks defensive abilities, such as good mobility or resistance. Due to that, he doesn't like to be touched by any means. Heroes with higher damage output and good mobility will often get easily near Zeus and trade damage (eventually causing Zeus's downfall). Such Heroes include: Lycan, Slark, Storm Spirit, Spectre and others.
Zeus
* Heroes with heavy magical nukes will take advantage of Slark's poor HP or force him to use Shadow Dance early: Lina, Lion, Zeus
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
* 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.
Zeus
* Some heroes with extreme range, like Zeus, Invoker or Clockwerk, can snipe your allies from anywhere after your Grave has expired.
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.
Zeus
* Heroes with spells that negate invisibility such as Bounty Hunter, Zeus and Slardar prevent her from saving her allies with Moonlight Shadow.
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.
Zeus
* Heavy nukers will do well against Cold Embrace (Lina, Zeus etc).
Additional:
* Any ally that Winter Wyvern tries to save with 
Cold Embrace can still be damaged by all of Zeus's spells.
* If Winter Wyvern tries to juke vision by flying up a cliff or in the trees, Zeus can gain vision there with Lightning Bolt or Thundergod's Wrath.
* If Zeus is forced to attack an ally by 
Winter's Curse, his unimpressive attack damage and attack speed means they won't be hurt much by him. Zeus will also stay near the back of fights away from his allies, making a deadly Curse less likely.
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.
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.
Zeus
* Zeus usually stays at the back in teamfights and it is hard for Sand King to find Zeus and knock him down before Zeus deals his damage.
* All of Zeus' abilities, especially Thundergod's Wrath, disables Sand King's Blink Dagger, effectively reducing Sand King's initiation and counter-initiation potential.
* Lightning Bolt deals damage to Sand King in Sand Storm and reveals him. It also interrupts channeling of Epicenter.
Zeus
* Heroes with low mobility that rely on spells: Zeus, Lina, Crystal Maiden.
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.
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.
Zeus
* Zeus can break Blink Dagger with his long range abilities and global range ultimate, Thundergod's Wrath.
* Lightning Bolt has a long range and a mini-stun, providing a way for him to cancel Black Hole from safe distances, assuming Enigma doesn't have his Black King Bar.
* Zeus's Aghanim's Scepter grants him Nimbus ability that has a global range and mini-stun, making it an even more effective way to cancel Black Hole before Enigma initiates with Black King Bar.
* Zeus is typically able to position himself at a safe distance from the fight, making him a difficult target to capture in a Black Hole.
Zeus
* Once you get a Black King Bar, squishy spellcasters like Zeus, Skywrath Mage and others will be probably easy to deal with.
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.
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
* 
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.
Zeus
* 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
* 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
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
* 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.
Zeus
* Zeus deals enormous amounts of magic damage, being one of the best heroes to burst down Timbersaw early in the game.
* Lightning Bolt's mini-stun can stop Timbersaw's from escaping a fight with Timber Chain.
Additional:
* Reactive Armor will not trigger from Zeus's spells or protect Timbersaw from their damage.
* Early game Timbersaw's strength is average and Zeus can heavily aid in bursting him down.
* Late game, if Timbersaw has built a lot of HP items, Zeus's passive Static Field will be more effective at chipping away Timbersaw's large HP pool.
* A Timbersaw who builds 
Pipe of Insight will be much more difficult to kill, as Zeus has no way to hold Timbersaw down, but Timbersaw will have less armor, mana, and damage than normal if he buys this item early game just to counter Zeus.
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.
Zeus
* Since Windranger is bad against magical damage, heroes with continuous magical damage or magical nukes can blast her: Zeus, Tinker, Leshrac, 
Viper, Skywrath Mage, Lion, Lina, Venomancer.
Zeus
* 
Corrosive Skin severely reduces Zeus's damage output throughout the game.
* During the laning stage, Viper can abuse Zeus' reliance on spells by hugging the creep wave. Zeus will take constant damage over time from Corrosive Skin unless he drives Viper from the lane or returns to farming in his absence.
* Prior to buying Blink Dagger or 
Force Staff, Zeus is fragile and possesses low mobility. Any of Viper's numerous slows can set up an easy kill.
Additional:
* Corrosive Skin counters Zeus in lane by canceling the effects of 
Clarity as Zeus relies on Arc Lightning to farm and secure last hits.
* Corrosive Skin also increases Viper's magic resistance to shrug off Zeus's magical nukes.
* 
Nethertoxin breaks Static Field.
* Due to Zeus' poor mobility, 
Viper Strike will cripple Zeus and will allow Viper and his teammates to land a lot of attacks.
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.
Zeus
* Zeus can deal a huge amount of damage, but he lacks defensive abilities, such as good mobility or resistance. Due to that, he doesn't like to be touched by any means. Heroes with higher damage output and good mobility will often get easily near Zeus and trade damage (eventually causing Zeus's downfall). Such Heroes include: Lycan, Slark, Storm Spirit, Spectre and others.
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
* Heroes who are reliant on illusions or summons: Chaos Knight, Broodmother, Naga Siren.
Zeus
* Heroes with powerful spammable abilities will prove problematic for Grimstroke as Ink Swell does not protect him from them: Zeus, Skywrath Mage, Tinker, Lina
Zeus
* Heroes that depend on disrupting fights with ability combos or big ultimate abilities are vulnerable to the long stun of Fiend's Grip: Disruptor, Death Prophet, Enigma, Faceless Void, Invoker, 
Lich, Magnus, Mars, Medusa, 
Outworld Destroyer, Phoenix, Puck, Queen of Pain, Shadow Fiend, Treant Protector, Underlord, Winter Wyvern, Witch Doctor, Zeus.
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.
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.
Zeus
* Thundergod's Wrath will often disable Earthshaker's Blink Dagger before a fight starts.
Zeus
* As a spellcaster, silences will nullify him entirely. Some notable examples are Death Prophet, Drow Ranger, Bloodseeker, Disruptor and many others.
* Doom, as usual, fits this description nicely.
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
Zeus
* Although Lightning Bolt and Thundergod's Wrath can reveal Templar Assassin during Meld, Zeus nonetheless has no way to deal with Refraction.
* Zeus is a rather squishy hero, falling easily to Templar Assassin's high burst damage.
Additional:
* 
Refraction blocks all of Zeus' damage and Zeus has no innate way of removing the instances quickly.
* 
Meld helps burst down Zeus' small health pool while he's still working through the Refraction instances.
* 
Psi Blades allow her to harass and zone Zeus in lane.
* Templar Assassin usually buys Blink Dagger, enabling her to quickly close the gap to Zeus' defensive positioning.
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.
Zeus
* Heroes who can provide True Sight are always credible threats: Slardar, Bounty Hunter, especially Zeus since his Lightning Bolt provides True Sight without the need to detect her beforehand to apply the debuff. So even a late-coming Zeus can easily scout a large area to reveal her, and she cannot purge herself from his sight with the dispel talent.
Naga Siren
* Ensnare disables Templar Assassin's invisibility and Blink Dagger (a core item on Templar Assassin), and her illusions will break Refraction easily.
Zeus
* Huskar's Burning Spears chip through his low health pool quickly.Consequently, he is forced to either invest on health regen or abandon the lane.
* Reliant on magic damage, there is little he can do against Huskar.
* Huskar will usually kill him if he gets Life Break off,given Zeus' poor mobility.
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.
Zeus
* Heroes who have most or all their abilities (damage or disable) unable to pierce spell immunity: Keeper of the Light, Lina, Lion, Zeus.
Additional:
* Rage is very useful against Zeus, as it negates magic damage and provides spell immunity. In addition, the increased attack speed can tear Zeus apart in combination with 
Open Wounds.
* Lifestealer can avoid Thundergod's Wrath with Infest.
Naga Siren
* Heroes with illusions: Chaos Knight, Naga Siren, Phantom Lancer, Terrorblade
Zeus
* Thundergod's Wrath strikes only the first Meepo.
Earthbinds are easy to hit and he'll quickly die from 
Poofs.
* Zeus has low mobilty so consecutive
Naga Siren
*
Naga Siren's Song of the Siren may be useful but Poof will destroy all of her illusions.