* Juxtapose allows Phantom Lancer to overwhelm Chaos Knight due to his single-target abilities.
* Doppelganger can be used to dodge Chaos Bolt.
* Since Phantom Lancer builds Diffusal Blade often, it can quickly drain Chaos Knight's low mana pool, leaving him unable to cast spells.
Additional:
* Chaos Knight's single target abilities are difficult to target against Phantom Lancer's illusions.
* Chaos Knight's lack of mobility makes him an easy target for Phantom Lancer to Phantom Rush and drain his already low mana pool.

* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer

* 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:
* With his 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.

* Jakiro's reliance on his abilities can cause struggles for heroes who rely on evasion or blinds to get upper hand: Phantom Assassin, Windranger, Riki, Troll Warlord, Keeper of the Light.

* 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.

* Heroes with silences: Puck, Doom, Riki.

* 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.

* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.

* Anti-Mage commonly builds Battle Fury, which can deal with Phantasm illusions easily.
* Counterspell, if timed right, will turn Chaos Bolt against Chaos 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 low amount mana.
* However, beware Anti-Mage is fairly fragile and cannot withstand heavy incoming physical damage at any points in the game, which Chaos Knight excels at. A good player will bait out Counterspell, and retaliate once it's over.

* Being an intelligence caster hero, Ezalor usually has a high mana pool and low health and armor, making him a prime target for Mana Void
* Ezalor's Illuminate damage and Solar Bind's magic resistance reduction are greatly reduced thanks to Counterspell. Counterspell can also block and reflect Solar Bind if timed properly.
* Anti-Mage usually is not hampered by Solar Bind or Will-O-Wisp thanks to Blink.
* However, despite all of this, if Keeper of the Light is played carefully and tops off his team's mana at all times, Anti Mage will not be able to get off a good Mana Void.

* Heroes that rely on illusions will suffer against Ion Shell, which kills them very quickly: Phantom Lancer, Chaos Knight, Naga Siren, Meepo.

* Heroes with hastes: Dark Seer, Lycan

* Illusion heroes will struggle against Primal Beast's area damage capability, such as Chaos Knight, Naga Siren, Terrorblade.

* Any hero who lanes very poorly will struggle with Primal Beast's potential snowball in the very early levels, like Keeper of the Light, Luna, Templar Assassin...

* 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.

* Mana Drain is very effective against heroes that have mana burn abilities such as Anti-Mage, Nyx Assassin and Keeper of the Light.

* 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 long duration.
Additional:
* 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.

* Being a cast-oriented hero, Ezalor will suffer from all of Silencer's abilities.
* Global Silence is a guaranteed lengthy silence which will render Ezalor useless in a teamfight.
* Arcane Curse and Last Word are good against any caster, since they are extremely potent.
* However, it should be worth mentioning that a smart Ezalor will buy Eul's Scepter of Divinity to dispel Silencer's abilities. Combined with the level 20 talent (Chakra Magic applies a basic dispel), Ezalor can purge Silencer's abilities off allies and himself alike.

* 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 Phantasms early on, and can still deal a lot of damage to them late game, revealing the real Chaos Knight.

* Heroes with strong area damage to destroy Phantasm illusions: Axe, Ember Spirit, Legion Commander, Phoenix

* Press the Attack can dispel Blinding Light or Solar Bind from a hero.
* Duel can be used to instantly take Keeper of the Light out of a team-fight.

* Echo Slam will deal a colossal amount of damage to your Phantasms, as will Fissure at lower levels.
* The area stuns from Aftershock will always stun Chaos Knight's illusions, since they can't use Black King Bar.
* However, Earthshaker should not attempt to fight a farmed Chaos Knight, since he will be completely obliterated by Chaos Knight's colossal damage output, even if he managed to land an Echo Slam
Additional:
* Echo Slam's damage potential increases due to Chaos Knight's Phantasm illusions.

* 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.
Additional:
* 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.

* Spiked Carapace can be used to reflect Illuminate damage and stun Keeper of the Light.
* Vendetta allows Nyx Assassin to follow Keeper of the Light around if he tries to split-push.
* Keeper of the Light is very squishy and will very quickly die to Vendetta and it's followup abilities.
* However, Mana Burn's Mana Burn can be more or less mitigated with Chakra Magic.

* 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.

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

* Cold Embrace protects Reality Rift targets.
* 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 high max 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.
* Chaos Knight's high health pool and tendency to not build magic resistance items will make Arctic Burn deal a lot of damage to him and his illusions.

* Ravage damages and disables Chaos Knight and his illusions.
* Anchor Smash deals respectable area damage, especially to Phantasms and lowers Chaos Knight's damage.
* Kraken Shell dispels Chaos Bolt and Reality Rift while providing protection from damage.

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

* Techies has great area of effect damage to deal with Phantasm illusions.
* Blast Off silences Chaos Knight, stopping him from using his disables and allowing his teammates to walk away from his heavy damage.
* Reactive Tazer will disarm all of Chaos Knight's illusions even if he has activated his Black King Bar.

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

* 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.
Additional:
* 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.

* 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.

* Untouchable will significantly slow down Chaos Knight's physical damage with Phantasm.
* Impetus deals double damage to illusions, making it effective against Phantasm.
Additional:
* Untouchable makes all of his attacks slow therefore he is unable to deal damage, especially his critical damage of Chaos Strike, also enables you to escape easily from his attacks.
* Reality Rift is still a danger because he can decrease a good amount of armor, making it dangerous because of her little armor stat
* Beware the timing of Silver Edge, a rather common item for Chaos Knight. With 5 seconds break, he can burst down Enchantress easily.

* Quill Spray quickly destroys Chaos Knight's Phantasms.

* Heroes with silences: Puck, Doom, Riki.

* Heroes that can jump and kill him: Meepo, Clinkz, Templar Assassin

* Once he buys Aghanim's Shard, Dazzle's Poison Touch can hex enemies, and hex can instantly kill illusions, making Dazzle strong against heroes who rely on illusions. Bear in mind that Chaos Knight is the exception because his Phantasms are strong illusions that are immune to abilities that can instantly kill illusions.

* With Bloodthorn, Clinkz becomes a strong counter to heroes who rely on evasion and blind such as Windranger, Phantom Assassin, Troll Warlord and Keeper of the Light.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

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

* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer

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

* Heroes with strong area damage to destroy Phantasm illusions: Axe, Ember Spirit, Legion Commander, Phoenix

* Black Hole usually catches Chaos Knight with all his illusions.
* Midnight Pulse deals damage based on current health, quickly killing Phantasm illusions.

* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.

* Heroes the make heavy use of illusions, like Chaos Knight, Phantom Lancer, Terrorblade, or Spectre can suffer from Crystal Maiden, as Freezing Field can quickly kill off the entire horde if not stopped.

* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.

* 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.

* Heroes with gap closing abilities will be easy targets for Berserker's Call: Phantom Assassin, Faceless Void, Slark, Chaos Knight, Morphling, Queen of Pain

Additional:
* Berserker's Call allows Axe to lock down Chaos Knight and his illusions even through Black King Bar.
* Counter Helix combined with Blade Mail clears illusions out in no time.

* Heroes with strong area damage to destroy Phantasm illusions: Axe, Ember Spirit, Legion Commander, Phoenix

Additional:
* 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.

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

* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit

* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit

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

* 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.

* Using Reality Rift sets up a Reverse Polarity on Chaos Knight and his illusions.
* Shockwave and Skewer kill Phantasm's illusions quickly, as can Empower cast on a melee carry.
Additional:
* All Magnus abilities are very good against Chaos Knight's Phantasm illusions.

* Crippling Fear prevents Keeper of the Light from using his spells to keep his team alive during team-fights.
* Dark Ascension is very strong against Keeper of the Light, as it allows Night Stalker to jump the backline and quickly kill the squishy Ezalor, especially when combined with the slow from Void.
Additional:
* Keeper of the Light's Aghanim's Scepter upgrade loses much of its power, due to Night Stalker being able to reduce the duration of daytime by a lot.

* 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.
Additional:
* 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.

* Blood Rite makes Ezalor chose between getting off Illuminate or getting silenced for a while, as Illuminate is a channeled ability.
* Blood Rite's silence can completely take Ezalor out of a teamfight, as he relies on his abilities to be useful.
* Keeper of the Light's only mobility source, his high movement speed (via his high base movement speed and through spirit form), is entirely countered by Rupture.