Juggernaut
* 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
* Axe will destroy her illusions by proccing Counter Helix more often due to him being hit by more attacks.
Juggernaut
* {Ability ID:Windrun|Windranger|16px} negates the damage from {Ability ID:Omnislash|Juggernaut|16px}.
* {Ability ID:Windrun|Windranger|16px} gives Windranger enough movement speed to get out of {Ability ID:Blade fury|Juggernaut|16px} range.
* {Ability ID:Focus fire|Windranger|16px} goes through {Ability ID:Blade Fury|juggernaut|16px}.
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.
Juggernaut
* 
Astral Imprisonment allows Outworld Destroyer to save himself or his teamates during Omnislash.
* Juggernaut's low mana from his low intelligence gain means that he'll take a lot of damage from 
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.
Juggernaut
* Heroes with built-in spell immunity can become immune to all of Outworld Destroyer's spells: 
Lifestealer's 
Rage and Juggernaut's Blade Fury.
Juggernaut
* Juggernaut's Omnislash is meaningless for Meepo who can share the damage across clones to save other allies.
Naga Siren
* Naga Siren's Song of the Siren may be useful but Poof will destroy all of her illusions.
Juggernaut
* Heroes with high armor and/or durability can handle Juggernaut's ultimate, such as 
Sven and 
Dragon Knight.
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.
Juggernaut
* Heroes with escaping and disjointing abilities can be good against Juggernaut:Anti-Mage 
Riki, 
Queen of Pain, 
Puck, 
Storm Spirit, 
Ember Spirit, 
Slark etc.
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.
Juggernaut
* Heroes with high armor and/or durability can handle Juggernaut's ultimate, such as Sven and Dragon Knight.
Additional:
* 
Warcry allows Sven to tank the damage from Omnislash due to its high armor gain.
* However Blade Fury provides spell immunity which blocks the stun from 
Storm Hammer.
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.
Juggernaut
* 
Fury Swipes is not protected by Blade Fury and allows Ursa to harass Juggernaut anytime.
* 
Enrage reduces the damage taken from Omnislash.
Juggernaut
* Drow Ranger can use Gust to push back Juggernaut before he can get in range to use Omnislash or Blade Fury.
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.
Juggernaut
* 
Decrepify prevents Omnislash damage, until Juggernaut gets a 
Nullifier.
* Without a disable, Pugna's high movement speed makes it harder to chase him with Blade Fury.
* Juggernaut has low mana and his skills cost large amount of mana. 
Nether Ward will hurt him more and even worse, the damage from the ward is inflicted before the Spell immunity provided by Blade Fury.
Additional:
* Decrepify is the perfect tool against Omnislash until he gets a Nullifier, and even then he will probably waste a couple of slashes before he uses it.
* Without an extra disable, Pugna's high movement speed makes it impossible to chase him with Blade Fury.
* Unlike some other carries like Slark or 
Phantom Assassin, Juggernaut's spells cost a hefty amount of mana and he will seriously get hurt by Nether Ward. Don't forget the damage from the ward is inflicted before the spell immunity is provided by Blade Fury.
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.
Juggernaut
* Troll Warlord's ability to attack as a ranged hero allows him to destroy Juggernaut's 
Healing Ward from afar.
* Battle Trance, when activated during Omnislash, allows Troll Warlord to survive the full duration of Omnislash and retaliate once it is over.
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.
Juggernaut
* 
Meat Hook can hit and displace Juggernaut during his Blade Fury.
* 
Dismember pierces Juggernaut's spell immunity from Blade Fury.
Juggernaut
* 
Bulwark mitigates Omnislash which deals physical damage, severely reducing its damage.
* Omnislash switch to opposite direction with each slash, so Mars can easily reduce most of its damage.
* However because {Ability ID:Blade Fury|Juggernaut} gives spell immunity Juggernaut can easily escape from {Ability ID:Arena Of Blood|Mars}.
Additional:
* Juggernaut deals mostly physical damage, which is easily mitigated with Bulwark.
* Juggernaut's Omnislash switches to opposite directions which each slash, so Mars can mitigate most of its damage since he only takes full damage from one direction: his back.
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.
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.
Juggernaut
* Heroes with abilities that can save teammates are also effective such as 
Shadow Demon, 
Dazzle, 
Oracle, 
Bane, 
Pugna, 
Tusk, 
Winter Wyvern, 
Io, 
Underlord, 
Treant Protector and 
Keeper of the Light.
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.
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.
Juggernaut
* Heroes with abilities that can save teammates are also effective such as Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.
Juggernaut
* Heroes with abilities that can save teammates are also effective such as Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.
Juggernaut
* With the exception of Magic Missile (unless the player takes the Level 25 Talent "Magic Missile Pierces Spell Immunity"), all of Vengeful Spirit's spells ignore Spell Immunity. This also makes her good against heroes with built-in Spell Immunity like Lifestealer or Juggernaut or heroes that tend to pick up Black King Bar, like Sven.
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.
Juggernaut
* 
Duel pierces spell immunity and forces him to attack Legion Commander, making him unable to use Omnislash.
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).
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: 
Spirit Breaker, 
Bloodseeker, 
Witch Doctor.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
Juggernaut
* Heroes with escaping and disjointing abilities can be good against Juggernaut:Anti-Mage Riki, Queen of Pain, Puck, Storm Spirit, Ember Spirit, Slark etc.
Juggernaut
* Chaotic Offering can stop heroes who like to use spell immunity and teleport scrolls to safely farm during the early to mid game, since it stuns and also goes through spell immunity. Notable examples: Juggernaut, Lifestealer.
Naga Siren
* Heroes who are reliant on illusions or summons: Chaos Knight, 
Broodmother, Naga Siren.
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).
Juggernaut
* Heroes with escaping and disjointing abilities can be good against Juggernaut:Anti-Mage Riki, Queen of Pain, Puck, Storm Spirit, Ember Spirit, Slark etc.
Juggernaut
* Heroes that rely on right-clicks will find themselves unable to damage opponents seriously after being affected by Static Link, like Sven, Bloodseeker, and Juggernaut.
Juggernaut
* Heroes with abilities that can save teammates are also effective such as Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.
Additional:
* Be ready to save an ally from Omnislash with your Disruption.
* Spawning Juggernaut's illusions is a great deal, as his base attack time is low and he has a critical strike. Illusions will benefit from both.
* Demonic Purge will prevent Juggernaut's desperate attempt to flee using Blade Fury. However, it cannot stop him if he is using 
Town Portal Scroll.
Juggernaut
* Heroes with abilities that can save teammates are also effective such as Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.
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.
Juggernaut
* Heroes with abilities that can save teammates are also effective such as Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.
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.
Juggernaut
* Illusion-based heroes are effective against Omnislash and Juggernaut's single-targeted damage: Naga Siren, Chaos Knight, Terrorblade,Phantom Lancer.
Juggernaut
* Blade Fury will not protect Juggernaut against Chronosphere or Time Lock.
* Faceless Void can Time Walk out of the range of Omnislash at all points of the game and with ease.
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
* 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.
Juggernaut
* Heroes with good mobility to avoid Jakiro's abilities and with good chase to punish Jakiro from pushing a tower: Bloodseeker, Ember Spirit, Juggernaut, Phantom Assassin, 
Weaver.
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.
Juggernaut
* Heroes with spell immunity: Juggernaut, 
Pangolier, 
Huskar.
Juggernaut
* Heroes with abilities that can save teammates are also effective such as Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.
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.
Juggernaut
* Heroes with spell immunity abilities won't be caught inside by Pit of Malice: Juggernaut, Lifestealer.
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.
Juggernaut
* While Blade Fury is on cooldown, Juggernaut can be easily killed by a standard 
Chaos Bolt & 
Reality Rift combo.
* 
Phantasm illusions can tank Omnislash.
Naga Siren
* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother
Juggernaut
* Keeper of the Light's 
Blinding Light makes Juggernaut miss his attacks. However, it can be dispelled easily with Blade Fury.
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
Juggernaut
* Juggernaut's Healing Ward keeps his team healthy even when pushing against Keeper of the Light's Illuminate.
* Blade Fury can dispel Blinding Light, as well as dodge an incoming Illuminate. Juggernaut can attack towers during Blade Fury, so he can dodge an Illuminate without having to stop pushing.
* Should Keeper of the Light obtain 
Will-o-Wisp through purchasing an Aghanim's Scepter, Juggernaut can make quick work of Ignis Fatuus without being interrupted by its pull.
* Keeper of the Light has low health, low armor, and no natural defense against Blade Fury.
Additional:
* Blade Fury allows him to be immune to all of Ezalor's abilities.
* Healing Ward heals his entire team, mitigating Ezalor's weak magical burst damage.
Juggernaut
* Blade Fury makes Juggernaut immune to the damage from Life Break and Burning Spears.
* It can be instantly activated the second Juggernaut sees Huskar flying towards him with Life Break, blocking all damage.
* Healing Ward effectively negates any damage-over-time from Burning Spears.
* Huskar has no defense against Omnislash and takes heavy damage due to his low armor.
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.
Juggernaut
* Juggernaut can trigger Proximity Mines while in Blade Fury, and can walk away from a initiation with Blast Off if Blade Fury is activated before the silence.
* Juggernaut ignores Reactive Tazer when he uses Omnislash, whether Techies used it to protect an ally or themselves.
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.
Juggernaut
* Juggernaut and Lifestealer have abilities (Blade Fury and Rage respectively) that prevent Crystal Maiden from using her spells on them in the early game, before Black King Bar and other magical reduction is even an issue.
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.
Juggernaut
* Blade Fury makes Juggernaut immune to all Nyx's abilities, except 
Vendetta.
* Omnislash. and 
Swiftslash can burst Nyx down, ignoring 
Spiked Carapace. However, Vendetta can be used to escape, canceling Omnislash/Swiftslash.
Additional:
* Juggernaut's entire skillset greatly counters Nyx Assassin's Spiked Carapace, his most important ability.
* Blade Fury allows Juggernaut to freely attack Nyx Assassin, and deal heavy damage to Nyx Assassin. Nyx Assassin cannot counter Blade Fury with Spiked Carapace because Blade Fury gives Juggernaut spell immunity. And besides Vendetta, Nyx Assassin has no other way of dealing damage to Juggernaut while he is spell immune.
* Healing Ward allows Juggernaut to recover himself and his allies from Nyx Assassin's damage output.
* Omnislash and Swiftslash from Aghanim's Scepter can quickly finish off Nyx Assassin. And just like Blade Fury, Nyx Assassin cannot counter neither Omnislash and Swiftslash from Aghanim's Scepter with Spiked Carapace because both abilities render Juggernaut invulnerable. And if Nyx Assassin has no Vendetta available to use for escaping, both abilities will kill him very quickly before he can do anything.
* Overall, any attempt for Nyx Assassin to gank and kill Juggernaut will hurt Nyx Assassin more than Juggernaut.
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.
Juggernaut
* Wraithfire Blast is quite predictable, and players with good reflexes will disjoint it with Blade Fury.
* Omnislash with 
Diffusal Blade & Aghanim's Scepter can prevent Wraith King from reincarnating unless he has his Aghanim's Shard that removes the mana cost from Reincarnation.
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.
Juggernaut
* Blade Fury allows Juggernaut to simply move out of Kinetic Field and to dodge Glimpse.
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
Juggernaut
* Heroes with stronger lane presence that can threaten to kill him: Batrider, Juggernaut, 
Ursa, Monkey King, Razor.
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 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.
Juggernaut
* Blade Fury's damage over time dispels 
Refraction almost instantly.
* Juggernaut's high armor allows him to survive for long enough to remove Refraction and threaten her with Omnislash as long as he or his team carries detection.
* Templar Assassin's short attack range makes it difficult for her to target a well-placed Healing Ward. She cannot splash onto it with 
Psi Blades.
Naga Siren
* Ensnare disables Templar Assassin's invisibility and Blink Dagger (a core item on Templar Assassin), and her illusions will break Refraction easily.
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.
Juggernaut
* Juggernaut's high attack speed lets him destroy a Supernova easily. He can even attack a Supernova during Blade Fury with his regular attacks.
* Blade Fury protects Juggernaut from all of Phoenix's spells (except Supernova, which pierces spell immunity).
* Blade Fury can also dispel the attack speed slow from 
Fire Spirits and the movement speed slow from 
Icarus Dive.
* Phoenix's Icarus Dive will not protect it from Omnislash unless it dives into creeps, and Phoenix's low armor makes for an easy kill.
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.
Juggernaut
* Juggernaut with Blade Fury
* 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.
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.
Juggernaut
* 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
* 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
* 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.
Juggernaut
* Blade Fury dispels the slow from Enchant, and can burst Enchantress down during the laning stage.
* Omnislash and Swiftslash's physical damage burst ignore untouchable.
* 
Silver Edge is a common item for Juggernaut for dealing with Untouchable.
Additional:
* Blade Fury dispels the slow from 
Enchant, spell immunity and used to burst her down during the early laning stage.
* Omnislash and Swiftslash's physical damage burst ignore 
Untouchable.
* Silver Edge is an ideal item for Juggernaut to deal with Untouchable, making her vulnerable to melee attacks.
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.
Juggernaut
* Blade Fury negates Kunkka's X Marks the Spot.
* Kunkka has no way to dodge Omnislash.
* Kunkka has no way to hit Healing Ward directly in battle, and it mitigates Ghostship and Tidebringer's damage.
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.
Juggernaut
* Illusion-based heroes are effective against Omnislash and Juggernaut's single-targeted damage: Naga Siren, Chaos Knight, Terrorblade,Phantom Lancer.
Juggernaut
* Heroes whose core item builds includes 
Monkey King Bar: Faceless Void, 
Windranger, Weaver, Juggernaut.
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.
Juggernaut
* Juggernaut's Healing Ward can help save allied supports when Spectre attempts a 
Haunt kill.
* Juggernaut has a stronger push potential than Spectre, enabling him to end the game early before Spectre can come online.
* Spectre is often paired with two supports that are often weak against Juggernaut.
* Juggernaut also tends to build a Manta Style, which can prevent 
Desolate from taking effect.
* Juggernaut is invulnerable against 
Dispersion while using Omnislash.
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.
Juggernaut
* Blade Fury grants spell immunity and also allows him to deal massive magical damage, both of which are Muerta's general counters.
* However, Juggernaut has no way of hurting Muerta through 
Pierce the Veil outside of Blade Fury, Juggernaut's only source of dealing magical damage. And unlike other abilities and items that turn the user ethereal, Pierce the Veil cannot be dispelled at all, making Nullifier useless for Juggernaut. This forces Juggernaut to buy 
Revenant's Brooch.
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
* 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.
Juggernaut
* Heroes who rely on physical damage are easily negated by Ghost Shroud: Phantom Assassin, 
Wraith King, Juggernaut.
Juggernaut
* Blade Fury blocks the damage done by 
Death Pulse and 
Reaper's Scythe. Additionally, 
Ghost Shroud decreases Necrophos's magic resistance, making him take more damage from Blade Fury.
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.
Juggernaut
* Blade Fury dispels most of Dark Willow's abilities, allowing Juggernaut to pass through Bramble Maze and cancel out Cursed Crown before the stun occurs.
* However, Dark Willow can tank Omnislash with 
Shadow Realm. As she is a valid target, but invulnerable to right clicks.
Additional:
* None of Dark Willow's spells pierce Spell Immunity, making Blade Fury a good counter against her. Additionally, it dispels 
Cursed Crown and Bramble Maze.
* Dark Willow is generally fragile, which results in Omnislash being devastating against her.
* However, if Shadow Realm is activated during Omnislash, then the attack damage is negated (though Omnislash can still jump to other enemies).
Juggernaut
* Blade Fury, similar to Rage, grants immunity to Invoker's spells and can dispel some debuffs as well.
* Omnislash renders Juggernaut invulnerable to Invoker's spells and can easily take Invoker down.
Additional:
* Juggernaut's instant spell immunity from Blade Fury. helps him dodge Invoker's combos. He can dispel the disables from 
Cold Snap and 
Deafening Blast and dodge the damage from 
Chaos Meteor, as well as walk through 
Ice Wall.
* Juggernaut's high DPS allows him to kill split pushing 
Forge Spirit(s) effortlessly, and his high armor prevents them from being a threat to him.
* However, Invoker can hit Juggernaut with 
Sun Strike through Blade Fury, making the 
Tornado and Sun Strike combo a threat if he does not dodge Tornado.
Juggernaut
* Kraken Shell provides no protection against Omnislash or Swiftslash.
* If timed correctly, Omnislash, Swiftslash and Blade Fury are all capable of dodging Ravage, giving Juggernaut several tools to render your strongest ability moot.
* Blade Fury is an effective way to harass Tidehunter in the laning stage as Tidehunter has no means of getting Juggernaut away from him. Healing Ward also greatly minimizes Tidehunter's ability to harass Juggernaut.
* 
Blade Dance minimizes the effectiveness of Anchor Smash's damage reduction.
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
* 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.
Juggernaut
* Because of her low range, Luna cannot easily destroy Healing Ward.
* Both Blade Fury and Omnislash are direct counters to Eclipse, offering Juggernaut spell immunity and invulnerabilty. Therefore, Luna will need assistance in taking down Juggernaut as going solo will not be successful.
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.
Juggernaut
* Skywrath's pitiful defences also make him easy meat to heroes with high burst like Juggernaut, Lion, or Phantom Assassin, the latter occasionally downing a support Skywrath in a single 
Stifling Dagger.
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.
Juggernaut
* Heroes with mobility/escape mechanisms to dodge Ancient Apparition abilites, or to easily jump on him: Riki, Queen of Pain, Phantom Assassin, Windranger, 
Bounty Hunter, Spirit Breaker, 
Night Stalker, Storm Spirit, Juggernaut, etc.
Naga Siren
* Heroes with illusions: Chaos Knight, Naga Siren, Phantom Lancer, Terrorblade
Juggernaut
* Heroes with abilities that can save teammates are also effective such as Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.
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
* Heroes with long cast animations can be continuously interrupted by Battery Assault: 
Centaur Warrunner, Jakiro, Leshrac, Naga Siren, Underlord.
Juggernaut
* Juggernaut is invulnerable while using Omnislash, meaning that neither Blade Mail or Power Cogs will save Clockwerk, this is especially common during the early laning phase.
* Blade Fury will also ignore any damage dealt by Battery Assault, as well as dealing heavy damage. As long as Juggernaut has mana to cast it.
* Overall, any attempt for Clockwerk to trap Juggernaut with Power Cogs will hurt him a lot more than the other way around.
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.
Juggernaut
* Blade Fury makes Juggernaut immune to Elder Titan's stun, so there is a high chance he wont get caught in your ultimate although Earth Splitter pierces spell immunity.
Juggernaut
* In general, heroes that deal burst in multiple instances will trigger Borrowed Time and heal Abaddon for a large amount, such as 
Skywrath Mage, 
Techies, Juggernaut, 
Shadow Shaman, or 
Ogre Magi.
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
* 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.
Juggernaut
* 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.
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.
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.
Juggernaut
* Heroes with spell immunity unless Lina chooses to play Carry role like Lifestealer with Rage and Juggernaut with Blade Fury.
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
Juggernaut
* Heroes with escaping and disjointing abilities can be good against Juggernaut:Anti-Mage Riki, Queen of Pain, Puck, Storm Spirit, Ember Spirit, Slark etc.
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.
Juggernaut
* Juggernaut deals most of his damage in the melee range and has no gap-closer. Sniper can easily harrass Juggernaut from afar with his long-ranged attacks and {Ability ID:Headshot|Sniper|16px} procs.Should Juggernaut decide to advance,Sniper has enough time to react and back off.
* Sniper's long range attack can destroy Healing Ward from a safe range, preventing any healing done to Juggernaut and/or his teammates.
* However, if Sniper is badly positioned, Juggernaut can easily terminate him.
Naga Siren
* Ensnare with her attacks allows Naga Siren to gank Sniper easily.
* Rip Tide removes Sniper's very little armor.
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.
Juggernaut
* Blade Fury makes Juggernaut immune against all of Snapfire's spells and allows him to get closer.
* A well-timed Omnislash allows Juggernaut to dodge Snapfire's spells, and she has no way to deal with it.
Juggernaut
* All abilities from Juggernaut (except Blade Dance) is very vulnearable steal to Rubick's 
Spell Steal.
Additional:
* Juggernaut looks like a carry that 
Rubick can hardly manfight, and it is surely the case that Rubick needs the assistance from his team to overwhelm the hero. However, his skills can be of great use for Rubick if used at the right occasions.
* Blade Fury is a great farming ability with low cooldown. What is bizarre about this ability is that it grants Rubick spell immunity and constant damage around him (movement speed buff with Aghanim's Shard). In early to mid game when all heroes has relatively low physical damage, the spell allows Rubick to become a temporary tank that enemy needs to run away from, extending Rubick's early killing potential.
* 
Telekinesis can throw a victim in range to eat up the damage from Blade Fury.
* Blade Fury can be stolen and used in a pinch to negate the damage from Blade Fury of Juggernaut. Note that with Aghanim's Shard Juggernaut can still deal damage to Rubick.
* Healing Ward, if stolen, serves as a magnificant healing tool within or after a teamfight. The constant area-of-effect healing helps greatly when your teammate is manfighting the enemy or escaping in a bad situation, and can even turn the fight around.
* Juggernaut is melee and cannot target an enemy Healing Ward easily unless he is in the midst of battle. Also, Juggernaut is not directly controllable during Omnislash and cannot attack Healing Ward.
* Omnislash is possibly the least useful spell Rubick can steal from Juggernaut. Although it is a good damage source in the early game, as a hero who seldom bulk up his physical damage, Omnislash falls quickly as the game goes on.
* It is worth mention that Omnislash could be used as an escape ability for Rubick with the help of Blink Dagger.
* Omnislash grants invulnerability at the midst of a fight. With quick reflex and judgement, Rubick can possibly dodge lockdowns and area disables, even steal a new spell when Omnislash is still on the fly.
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
* 
Flak Cannon and Call Down can easily clear Naga Siren's illusions.
Juggernaut
* Blade Fury and Omnislash allows Juggernaut to avoid Gyrocopter's area attacks entirely.
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.
Juggernaut
* Heroes with escaping and disjointing abilities can be good against Juggernaut:Anti-Mage Riki, Queen of Pain, Puck, Storm Spirit, Ember Spirit, Slark etc.
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.
Juggernaut
* Heroes with escaping and disjointing abilities can be good against Juggernaut:Anti-Mage Riki, Queen of Pain, Puck, Storm Spirit, Ember Spirit, Slark etc.
Juggernaut
* Heroes with spell immunity or pseudo-blinks which provide invulnerability: Lifestealer, Juggernaut, Omniknight, Huskar, and Tusk have spells which allow them to easily escape Dream Coil.
Juggernaut
* 
Nature's Call can be used to tank Omnislash in the early to mid game due to their high health pool combined.
* 
Sprout can trap Juggernaut, even if he is using Blade Fury. Aghanim's Shard upgraded Sprout can also prevent Juggernaut from escaping if he buys Battle Fury.
* Once Nature's prophet reach lv 20 with leash talent on Sprout, he can stop Juggernaut from escaping with Blade Fury and TPing away.
* Nature's Prophet can farm and push much faster than Juggernaut, acquiring map control before he can do much.
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.
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.
Juggernaut
* Blade Fury protects Juggernaut from all of Tiny's magic burst damage.
Juggernaut
* Heroes with escaping and disjointing abilities can be good against Juggernaut:Anti-Mage Riki, Queen of Pain, Puck, Storm Spirit, Ember Spirit, Slark etc.
Additional:
* Blade Fury does not offer any protections against 
Essence Shift, as it can go through spell immunity and reduces attribute.
* Slark can pounce away from Juggernaut and he cannot prevent or chase slark.
* 
Shadow Dance prevent Juggernaut from using Omnislash altogether, while regen himself at a higher rate. Slark can freely hit juggernaut without any fears of retaliation.
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 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.
Juggernaut
* 
Guardian Angel completely negates all physical damage, including Omnislash.
Additional:
* Omnislash (and Swiftslash) is blocked by Guardian Angel.
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
* 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.
Juggernaut
* 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.
Juggernaut
* Low-health, normally mobile carries who rely entirely on raw attack damage are vulnerable to Bane's nukes and disables: Anti-Mage, 
Clinkz, 
Drow Ranger, Faceless Void, Gyrocopter, Juggernaut, Meepo, 
Mirana, Monkey King, Morphling, Phantom Assassin, Phantom Lancer, Riki, Shadow Fiend, Slark, 
Sniper, Terrorblade, Troll Warlord, Weaver.
Additional:
* Fiend's Grip pierces spell immunity, rendering Blade Fury nearly useless.
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.
Juggernaut
* Omnislash spreads on both the bear and the druid, allowing them to survive.With enough levels,the bear can soak the ability alone and possibly dragging him to a dangerous location.
* Juggernaut cannot manfight the duo in the early game,because of their tankiness. If opposed in lane,Lone Druid can shut him down.
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.
Juggernaut
* Enigma's Eidolons from
Demonic Conversion can help soak Juggernaut's 
Omnislash in the early game, mitigating the damage and wasting it on disposable summons. Should Juggernaut choose to kill Enigma's Eidelons with 
Blade Fury, he will leave himself open to Enigma's disables. 
Black Hole and 
Midnight Pulse's damage and disable can pierce through Juggernaut's 
Blade Fury.
Omnislash damage, wasting its damage potential.
Black Hole and 
Midnight Pulse damage pierces 
Blade Fury, especially when he tries to escape with it.
* Enigma's
Additional:
* Enigma's Eidolons can absorb
*
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.