* With his AoE damage, Jakiro can easily kill Chaos Knight's Phantasm illusions.
* Chaos Knight usually doesn't buy a Black King Bar, making him vulnerable to an Ice Path into Macropyre combination.
Additional:
* Ice Path and Macropyre punish Reality Rift with a long stun and heavy damage across all illusions.

* Jakiro's abilities deal damage over time, which can disrupt Magnus's attempts to initiate with Blink Dagger and Reverse Polarity.
* Macropyre not only disables Blink Dagger for a considerable duration, but can also destroy Trees, revealing Magnus's cover and position.

* Decrepify turns the target ethereal, protecting them from Chaos Knight's and his illusions' attacks.
* Life Drain instantly destroys illusions. It can effectively negate Phantasm when upgraded with Aghanim's Scepter.
* Nether Blast quickly clears out illusions and can harass Chaos Knight in lane.

* 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.

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

* Abaddon could punish Chaos Knight for using his Phantasm and Reality Rift combo on him with Aphotic Shield. Additionally, it provides extra protection against Chaos Knight's potential to take Abaddon down quickly.
* Furthermore, Abaddon's Borrowed Time makes it utterly impossible to burst Abaddon down, effectively reducing the amount of targets Chaos Knight can threaten by 1 for the entire game.

* 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.

* Ravage damages and disables Chaos Knight's army.
* Anchor Smash deals respectable area damage at early levels and lowers Chaos Knight's damage.
* Kraken Shell dispels Chaos Bolt and Reality Rift while providing protection from damage.

* Illusion-based heroes such as Naga Siren or Chaos Knight are vulnerable to Phoenix's DPS and attack speed slow, as their illusions, no matter how many, will be unable to deal enough damage to actually be a threat, and they will all be completely useless against the Supernova.

* Phoenix will usually be on the sidelines or further back ready to use Sun Ray. Even after Magnus successfully uses Reverse Polarity and skewer Phoenix's teammates, Phoenix can usually counter-initiate using all of its abilities.

* Anti-Mage commonly builds Battle Fury, which can deal with Phantasm illusions easily.
* Counterspell, if timed right, will turn Chaos Bolt against the Knight, and can set up for a kill if he is not careful.
* Even if Counterspell is on cooldown, Blink can almost always dodge a Chaos Bolt because of its slow projectile.
* Mana Break will quickly drain Chaos Knight's mana.

* Heroes who build mana boosting items but have low mana regeneration are especially vulnerable against Mana Break and Mana Void: Timbersaw, Slark, Shadow Fiend, Clinkz, Bristleback Nyx Assassin, Magnus

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

* Dragon Blood's armor bonus greatly reduces the damage dealt by Phantasm.
* Breathe Fire and Elder Dragon Form's splash damage quickly destroy illusions and reduces their damage output.

* Phantasms can be easily killed with Purification.
* Heavenly Grace dispels the stun from Chaos Bolt and the armor reduction from Reality Rift.
* Guardian Angel works well against Chaos Knight's overwhelming reliance on physical burst damage.
Additional:
* Purification heals a teammate targeted by Reality Rift and heavily damages Chaos Knight and his illusions in the process.
* Guardian Angel blocks all of Chaos Knight's damage for a duration.

* 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.

* Tidebringer, Torrent and Ghostship destroys Chaos Knight's Phantasm army all through the game.

* 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.

* 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.

* Great Cleave is very effective against Chaos Knight's illusions.
* Storm Hammer's radius can catch all of Chaos Knight's illusions at once, especially after Reality Rift.
* Warcry shields Sven and his teammates against Chaos Knight's burst physical damage.
Additional:
* Storm Hammer's faster projectile speed and cast time allows Sven to stun Chaos Knight and his illusions before he can cast Chaos Bolt.
* Warcry's armor bonus counteracts Reality Rift's debuff and reduces Chaos Knight's damage output.
* Great Cleave and God's Strength devastates Phantasm illusions.

* Tinker can break Magnus's Blink Dagger using March of the Machines and Heat-Seeking Missile, therefore delaying any initiation or making Magnus use Skewer or Force Staff to initiate. Tinker usually gets his own Blink Dagger as well, which makes him harder to lock down unless Magnus commits Reverse Polarity only for Tinker.

* With Aghanim's Scepter, Tinker's Laser completely stops Chaos Knight's damage, forcing him to buy either a Black King Bar for his own survivability while leaving his illusions still vulnerable, or a Monkey King Bar leaving him still vulnerable to Tinker's nukes, though improving his damage.
* Tinker rarely finds himself in the middle of a fight, which is where Chaos Knight typically thrives, and even in the rare cases of being so, at level 3 Tinker's constant rearm and blink away can kite and dodge Chaos Knight's spells reliably, so Chaos Knight has very little catch against Tinker's mobility. This gives Tinker impunity to create more chaos in a teamfight than Chaos Knight can control, laying down the field with March of the Machines and constantly being hit by rockets and lasers.
Additional:
* Tinker's Aghanim's Scepter upgraded Laser can blind him and all of his Phantasm illusions.

* 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.

* Because of his massive AoE damage, Sand King is very effective against illusion heroes: Chaos Knight, Phantom Lancer, Terrorblade,...

Additional:
* Sand King's massive area damage output, particularly Epicenter, allows him to quickly take down Chaos Knight and his illusions.
* He can apply Caustic Finale to illusions with attacks for extra damage.

* The area of effect damage from Midnight Pulse and Black Hole help deal with Chaos Knight's illusions.
Additional:
* Black Hole usually catches Chaos Knight with all his illusions.
* Midnight Pulse deals damage based on max health, quickly killing Phantasm illusions.

* 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.

* Magnus has very mediocre damage against Alchemist, because he can survive the stun duration of Reverse Polarity with Chemical Rage.

* Puck's area of effect nukes in the form of Illusory Orb and Waning Rift clears Phantasm illusions from the early game to mid game.
* Phase Shift can be used to disjoint Chaos Bolt.

* Flak Cannon destroys Chaos Knight's illusions very quickly.

* Venomancer can simultaneously scout Magnus hiding in trees and putting Blink Dagger on cooldown with Plague Wards, which makes Magnus real problems to blink and initiate.
Additional:
* Similar to Night Stalker, Venomancer can simultaneously scout Magnus hiding in trees and put Blink Dagger on cooldown with Plague Ward, which gives Magnus problems when trying to blink in and initiate.

* Storm's Dispel Magic combined with Thunder Clap deals high damage against Chaos Knight's illusions even in the late game.
* Chaos Knight's reliance on physical damage is easily hindered by Drunken Brawler.
* Chaos Knight's lack of area effect and mobility makes him easily overwhelmed by Primal Split.
Additional:
* Dispel Magic from {U:Storm} can instantly kill the Phantasm army early on, and can still deal a lot of damage to them late game, revealing the real Chaos Knight.

* Treant Protector can usually scout out Magnus in the trees with Eyes in the Forest and disrupt his initiation attempts. He can also counter Magnus' initiation with Overgrowth.

* Cold Embrace protects targets of Reality Rift.
* Winter's Curse turns Phantasm illusions against Chaos Knight or a teammate.
* Splinter Blast deals decent area damage to Phantasm illusions.
* Arctic Burn's percentage-based damage quickly wears down Chaos Knight's health.
Additional:
* Winter Wyvern can make Chaos Knight's illusions attack the real one, provided the player knows who it is.
* Alternatively, Winter's Curse can make Chaos Knight and all his illusions attack one of his allies.
* Cold Embrace protects ally who is focused by Chaos Knight.
* Splinter Blast deals decent area damage to Chaos Knight's illusions.

* Echo Slam's damage potential increases due to Chaos Knight's Phantasm illusions.
Additional:
* Echo Slam will deal a colossal amount of damage to your army, as will Fissure at lower levels.
* The area stuns from Aftershock will always slow down your illusions, since they can't have spell immunity.

* Chain Frost can eliminate Chaos Knight's Phantasm army, especially after he clumped up using Reality Rift.
* Frost Shield will heavily reduce his army's effectiveness.
Additional:
* Lich's Chain Frost, especially after obtaining its respective talent that provides unlimited bounces, can take out all of Chaos Knight's illusions quickly.
* An Aghanim's Scepter-upgraded Sinister Gaze can hypnotize Chaos Knight and his illusions while also draining his already low mana pool.

* Reactive Armor helps Timbersaw to endure the damage from Chaos Bolt and Reality Rift combo.
* Timbersaw's large amount of pure damage AoE nukes clears Chaos Knight's illusions quickly, drastically reducing his damage.
Additional:
* Strong area damage, particularly from Whirling Death and Chakram, lets Timbersaw clear out illusions quickly.
* Whirling Death directly reduces Strength from both Chaos Knight and his Phantasm illusions, reducing both the damage output and raw health that the hero relies on.
* Reactive Armor quickly builds stacks against Phantasm illusions, making Timbersaw hard to kill.
* Timber Chain allows Timbersaw to escape while surrounded.

* Berserker's Call and Counter Helix makes short work of Chaos Knight's Phantasms.
Additional:
* Berserker's Call allows Axe to lock down Chaos Knight and his illusions.
* Counter Helix combined with Blade Mail clears illusions out in no time.

* Spectre can use Haunt to intercept and disrupt Magnus's initiation attempts.
* Spectral Dagger can severely slow down Magnus after he uses Skewer.
* Magnus often travels alone when he is trying to initiate, so Desolate can be very effective against him.
Additional:
* Spectre disables Magnus' Blink Dagger using her ultimate, and later into the game can usually outlive Reverse Polarity's duration.

* Maledict cannot be dispelled by Phantasm, and can be used to tag the real Chaos Knight hiding within his illusions.
* If Witch Doctor has an Aghanim's Scepter, Death Ward will bounce between Chaos Knight's illusions, destroying them quickly.
* However, Death Ward is easily interrupted by Chaos Bolt until Witch Doctor buys Glimmer Cape or Black King Bar.

* Ember Spirit is evasive and can dodge close encounters with melee heroes like Chaos Knight. Ember Spirit can't be caught with the slow from Reality Rift, and Flame Guard and Sleight of Fist can bring Phantasm's illusions down quickly.

* Quill Spray quickly destroys Chaos Knight's Phantasms.

* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother

* 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.

* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother

* Heroes that rely on illusions will suffer against Ion Shell, which kills them very quickly: Phantom Lancer, Chaos Knight, Naga Siren, Meepo.
* Heroes that rely on illusions typically spawn very strong illusions inside your Wall of Replica that you should use against them or their team.

* Illusion based heroes (like Chaos Knight and Terrorblade) can't use their illusion beneficially against Sanity's Eclipse's high AoE burst damage.

* 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.

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

* 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.

* 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.

* One of Lion's level 20 talents lets Mana Drain affect 2 secondary targets. This can make things difficult for heroes like Phantom Lancer, Chaos Knight, and Terrorblade who rely on illusion armies.
* Mana Drain and Hex instantly kill any illusions. Finger of Death upgraded with Aghanim's Scepter also shreds most illusions.
* One of Lion's level 20 talents lets Mana Drain affect 2 secondary targets. This can make things difficult for heroes like Phantom Lancer, Chaos Knight, and Terrorblade who rely on illusion armies.

Additional:
* Mana Drain is a real problem to Chaos Knight in the early game, considering his already low mana pool.
* Aghanim's Scepter upgraded Finger of Death is an AoE ability, which can deal a tremendous amount of damage to his illusions.
* Lion has two abilities that can instantly kill illusions. Provided that he does not get stunned by Chaos Bolt first, Lion can render Phantasm near-useless.

* Heroes that have high health but little to no magic resistance are easy prey for Necrophos, as no matter how high they build their health up, Reaper's Scythe will kill them outright as long as they fall under a certain threshold, and Heartstopper Aura will deal the same amount of damage regardless, decaying their health the longer they stay within range. As such, Strength heroes like Chaos Knight, Centaur Warrunner or Magnus are good targets for his ultimate.

* Heroes that have high health but little to no magic resistance are easy prey for Necrophos, as no matter how high they build their health up, Reaper's Scythe will kill them outright as long as they fall under a certain threshold, and Heartstopper Aura will deal the same amount of damage regardless, decaying their health the longer they stay within range. As such, Strength heroes like Chaos Knight, Centaur Warrunner or Magnus are good targets for his ultimate.

* Heroes who take a long time to become strong are in for a rough mid game, such as Outworld Destroyer, Magnus, Medusa, and Anti-Mage.

* 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.

* Heroes who are reliant on illusions: Chaos Knight, Phantom Lancer, Naga Siren.

* Heroes who can disable Mars but cannot do any damage to him, meaning he just tanks their abilities: Doom, Magnus.

* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, Chaos Knight, Terrorblade, Naga Siren

* Heroes who are reliant on illusions or summons: Chaos Knight, Broodmother, 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.

* 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.

* Heroes reliant on illusions or summons: Broodmother, Chaos Knight, Naga Siren.

* Heroes that have an escape that doesn't disjoint projectiles: Mirana, Faceless Void, Magnus

* 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.

* Melee carries will have a hard time against Tiny's Craggy Exterior: Phantom Assassin, Chaos Knight, Juggernaut.

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

* Magnus cannot manfight Huskar even with Empower, Berserker's Blood's high attack speed and health regeneration, combined with Huskar's high health and Burning Spear stacks will allow Huskar to kill Magnus before he can kill him.
* From a safe distance, Huskar can surprise and counter Magnus's initiation with Life Break and Burning Spear.
* Burning Spear also deals damage over time, disabling Blink Dagger and preventing him from initiating or escaping.

* If Luna can use Eclipse in anticipation, Magnus will be killed before he can even manages to cast Reverse Polarity.
* Aghanim's Scepter upgraded Eclipse is a very good counter-initiation tool against Magnus when he casts Reverse Polarity, granted as long as Luna can cast it from safe distance.

* Rupture deals extra damage to Magnus during Skewer or Force Staff, preventing him from escaping or counter-initiating, forcing him to invest on a Linken's Sphere.

* Disruptor can disable Magnus's Blink Dagger using Thunder Strike during a considerable duration, disrupting his initiation attempts.
* Glimpse brings Magnus back after he escapes with Skewer and/or Force Staff.
* Static Storm if used on a fight can prevent Magnus from using Reverse Polarity after he jumps in.

* Shrapnel can sometimes scout out Magnus and also place his Blink Dagger on cooldown. Aside from that, Sniper likes to stay far back behind enemy lines, so it's difficult to catch him with Reverse Polarity unless you already have vision on him and can Skewer him to the rest of his team.