* 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.

* Guardian Angel protects allies from Death Ward's physical damage.
* Purification and Heavenly Grace will most likely save teammates from dying to Maledict.

* 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.

* Death Ward does little damage against Dragon Knight's armor, and Dragon Knight's high health regeneration minimizes damage from Maledict.

* 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.

* Kraken Shell dispels the stun from Paralyzing Cask. However, it does not dispel the damage from Maledict.
* Once Witch Doctor first uses his Death Ward in team fights, Tidehunter can simply cancel it with Ravage, turning the tables against him, especially if Witch Doctor does not have a Black King Bar.
* As a precaution, let Tidehunter use Ravage first before channeling Death Ward to turn a team fight in your favor.

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

* Heroes with long channeling abilities like Witch Doctor are easy targets for Kunkka to interrupt in team fights.

Additional:
* Torrent can cancel Death Ward from a far distance.

* Heroes with channeled abilities can be interrupted by a long-range Fissure: Crystal Maiden, Witch Doctor, Bane, Pugna, Pudge.

* 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.
* Earthshaker should not attempt to fight back a full slotted Chaos Knight however, since he will be completely obliterated by Chaos Knight's colossal damage output, even if he managed to land an Echo Slam

* Low health spellcasters: Lina, Witch Doctor, Tinker, Keeper of the Light, all rely heavily on their spells and are fragile heroes. They all also have avoidable spells, allowing Puck to get to them and quickly burst them down.

* 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.

* Death Ward's first target (before it bounces) can evade it, therefore Windranger and Phantom Assassin are poor choices to use it on.

* 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 powerful channeling abilities are easily interrupted by Phantom's Embrace: Bane, Pudge, Witch Doctor, Crystal Maiden, Enigma.

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

* Heroes who rely on channeling abilities can be interrupted in teamfights by Rolling Thunder: Crystal Maiden, Pugna, Witch Doctor

* 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

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

* Heroes with slow movement speeds and small health pools (supports like Crystal Maiden or Witch Doctor) are easy targets for Phoenix. Should they be inflicted by its DOT debuffs, they will be very quickly killed without even getting a chance to fight back.

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

* Heroes with plenty of summons, such as Broodmother or Nature's Prophet can have their minions soak up most of your Paralyzing Cask.

* 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.

* 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.

* 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.
Additional:
* Juxtapose allows Phantom Lancer to overwhelm Chaos Knight due to his single-target abilities.
* Doppelganger can be used to dodge Chaos Bolt.
* Spirit Lance can be used to harass Chaos Knight during the early game.
* Since Phantom Lancer builds Diffusal Blade often, it can quickly drain Chaos Knight of all his mana, leaving him unable to cast spells.

* 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.

* 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.

* Sacred Arrow can be used to interrupt Death Ward from a safe distance, forcing him to cancel it to dodge or get hit.
* Paralyzing Cask is a slow-moving stun, and Mirana can Leap away from her allies to keep it from bouncing.
* Witch Doctor has low health and can easily be killed with an Aghanim's Scepter combo or just when hit with an arrow.

* 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.

* Luna has a love/hate relationship with illusions and summons. On one hand, they can tank damage from Eclipse, but on the other hand, she can easily clear them before Eclipse with Moon Glaives. Examples include 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).

* Lucent Beam interrupts Death Ward from a decent range.
* Eclipse kills Witch Doctor during Death Ward, even through Glimmer Cape.

* Without Dust of Appearance or Sentry Wards, Riki is able to silence Witch Doctor with Smoke Screen, and is likely to build a Diffusal Blade, leaving Witch Doctor without mana to cast Voodoo Restoration, as well as Skull Basher to interrupt Death Ward.

* 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.

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

* It is especially easy for Oracle to negate the damage from Maledict, and even heal through it with Fate's Edict and Purifying Flames.
* If by some miracle an enemy is still about to die because of Maledict, he can still save him with False Promise.

* Wukong's Command and Boundless Strike combo can easily cause havoc on Chaos Knight by destroying all of his powerful illusions.
* Chaos Knight without Phantasm cannot deal with Jingu Mastery at all.

* Paralyzing Cask's short stun rarely prevents Monkey King from ambushing Witch Doctor.
* Death Ward's long channel is easily interrupted by Boundless Strike.

* Beware of placing the Death Ward if Chronosphere is off cooldown, as it will cancel the effect and leave Witch Doctor vulnerable if he does not react in time.

* 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.

* Quill Spray quickly destroys Chaos Knight's Phantasms.

* 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.

* 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
Additional:
* Untouchable will definitely slow all of your attack animations making you unable to deal any damage especially critical damage from Chaos Strike.

* 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.
* Timbersaw should be careful if Chaos Knight manage to farm a Bloodthorn however, as it can silence Timbersaw on a whim, rendering him useless for a lengthy duration.
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.

* Witch Doctor's Maledict burst damage can be prevented by Sunder if timed correctly.
* Death Ward deals physical damage, and Terrorblade's high armor can help him survive against Death Ward.
* However, be careful that Paralyzing Cask is commonly tricky to dodge as Terrorblade, due to his reliance on illusions, and Maledict can kill Terrorblade if he has no target to be Sundered with, especially in the early game.

* 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.

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

* 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.

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

* 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 small health pools and little to no escape mechanisms are even easier prey for Necrophos. Ghost Shroud's slow will allow him to catch him with them, and get nuked down with his abilities, even preventing retaliation due to Reaper's Scythe's stun. Such heroes include Crystal Maiden, Witch Doctor, Warlock or Shadow Fiend.

* 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.

* 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.

* Heroes like Slark, Witch Doctor and others also tend to suffer in Ice Blast's heal denial.

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

* 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 who have channeled abilities can be stunned by Light Strike Array, like Witch Doctor with Death Ward and Bane's Fiend's Grip.

Additional:
* Light Strike Array cancels out Death Ward from a long distance.

* Heroes with plenty of summons, such as Broodmother or Nature's Prophet can have their minions soak up most of your Paralyzing Cask.

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

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

* 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.

* 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.

* 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.
* Beware, however, 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.

* Vengeful Spirit has two abilities to interrupt Death Ward, even through Black King Bar.