Brewmaster
* Blinking heroes like 
Anti-Mage or 
Queen of Pain can often chase down an injured Brewmaster after his ultimate expires.
Chaos Knight
* 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.
Chaos Knight
* Tidebringer, Torrent and Ghostship destroys Chaos Knight's 
Phantasm army all through the game.
Chaos Knight
* 
Juxtapose allows Phantom Lancer to overwhelm Chaos Knight due to his single-target abilities.
* 
Manta Style is a natural item from Phantom Lancer's is very harder from Chaos Knight's kill him a lot from Phantom Lancer's illusion and Manta Style from Phantom Lancer's impacted Juxtapose .
* 
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.
Chaos Knight
* 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 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.
Chaos Knight
* 
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.
Chaos Knight
* 
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.
Chaos Knight
* Flak Cannon destroys Chaos Knight's illusions very quickly.
Brewmaster
* Brewmaster is slow and has low armor, making his laning stage very difficult against Geminate Attack.
* Apart from the slow moving 
Hurl Boulder, which can be disjointed, he has no control to catch Weaver.
Chaos Knight
* 
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.
Chaos Knight
* 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.
Chaos Knight
* 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.
Brewmaster
* 
Exorcism kills Primal Split's units very quickly.
Chaos Knight
* 
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.
Chaos Knight
* Quill Spray quickly destroys Chaos Knight's Phantasms.
Chaos Knight
* 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.
Chaos Knight
* 
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.
Chaos Knight
* 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.
Chaos Knight
* 
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.
Brewmaster
* 
Hex's instant cast time will force Brewmaster into the awkward situation of needing some form of spell immunity or block to prevent being immediately hex upon blinking in, or wait until Lion has used all his crowd control before entering a fight. His direct magic burst also makes Brewmaster's Drunken Brawler worthless versus Lion.
Chaos Knight
* 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.
Chaos Knight
* 
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 Chaos Knight's attacks slow therefore he is unable to deal damage, especially his critical damage of 
Chaos Strike, also enables Enchantress to escape easily from his attacks.
* However, Reality Rift can still pose a danger to Enchantress because Chaos Knight can decrease a good amount of armor, making it dangerous because of her little armor stat, as he can burst down Enchantress easily if any of Chaos Knight's allies can apply a break on Enchantress.
Chaos Knight
* 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.
Chaos Knight
* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: 
Naga Siren, 
Phantom Lancer, 
Broodmother
Chaos Knight
* 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.
Chaos Knight
* Heroes who are reliant on illusions: Chaos Knight, Phantom Lancer, Naga Siren.
Brewmaster
* Blinking heroes like Anti-Mage or Queen of Pain can often chase down an injured Brewmaster after his ultimate expires.
Chaos Knight
* Heroes with strong area damage to destroy Phantasm illusions: 
Axe, 
Ember Spirit, 
Legion Commander, 
Phoenix
Chaos Knight
* Illusion heroes will struggle against Primal Beast's area damage capability, such as Chaos Knight, Naga Siren, Terrorblade.
Chaos Knight
* Heroes with strong area damage to destroy Phantasm illusions: Axe, Ember Spirit, Legion Commander, Phoenix
Chaos Knight
* Heroes who are reliant on illusions or summons: Chaos Knight, Broodmother, Naga Siren.
Chaos Knight
* 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.
Chaos Knight
* 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 
Fiend's GAte 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.
Chaos Knight
* 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
Chaos Knight
* 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.
Chaos Knight
* 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.
Chaos Knight
* 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.
Brewmaster
* Heroes with strong team-fight abilities (especially ultimates) like 
Tidehunter, 
Brewmaster, 
Death Prophet, etc.
Chaos Knight
* Heroes reliant on illusions or summons: Broodmother, Chaos Knight, Naga Siren.
Chaos Knight
* 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.
Chaos Knight
* 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.
Brewmaster
* 
Hex's instant cast time will force Brewmaster into the awkward situation of needing some form of spell immunity or block to prevent being immediately hex upon blinking in, or wait until Shaman has used all his crowd control before entering a fight.
* Brewmaster also has no defense against Shadow Shaman lockdowns.
Chaos Knight
* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, 
Beastmaster, 
Bloodseeker, 
Clockwerk, 
Doom, 
Shadow Shaman.
Brewmaster
* After Brewmaster has committed Thunder Clap and Cinder Brew to gank, Bane can use 
Nightmare on Brewmaster to wait out the debuffs, and might even turn the tables by buying time for allied reinforcements.
* Bane can also prevent Brewmaster from using Primal Split with his long disables.
Chaos Knight
* Heroes with illusions and summons can swarm Bane, who has no area abilities outside from Aghanim's Shard upgraded 
Brain Sap: Broodmother, Chaos Knight, Naga Siren, 
Nature's Prophet, Phantom Lancer, Terrorblade, 
Visage, 
Warlock, Wraith King.
Additional:
* Phantasm's illusions make it difficult for Bane to target Chaos Knight with Nightmare, 
Enfeeble, and 
Fiend's Grip.
* Chaos Bolt is a comparatively low cooldown tool to interrupt Fiend's Grip.
* Nightmare can be transferred by Phantasm illusions.
Brewmaster
* 
Ancient Seal's instant cast time will often silence Brewmaster before he can do anything.
* Brewmaster also has no defense against Skywrath Mage's massive magical damage.
Chaos Knight
* Skywrath Mage also has a terrible time fighting against anything that isn't a hero. His skills are mostly target-based and he has terrible strength and agility, he can easily be kited or harassed by illusion-based heroes like Chaos Knight and Phantom Lancer, or by Heroes that summon other units like 
Lone Druid, 
Lycan and Beastmaster.
Chaos Knight
* 
Black Hole usually catches Chaos Knight with all his illusions.
* 
Midnight Pulse deals damage based on current health, quickly killing Phantasm illusions.
Brewmaster
* Heroes who produce many summons will have a hard time against Storm's Dispel Magic during teamfight: Broodmother, 
Enigma, Nature's Prophet.
Brewmaster
* If Ursa uses 
Enrage Brewmaster can use Cyclone to render him harmless during his ultimate.
* Brewmaster has two spells to slow down Ursa, allowing his team to kite around him easily.
Chaos Knight
* Ursa cannot effectively fight against Phantasm's illusions with his single-target damage.
* Chaos Bolt's potentially long stun with Chaos Bolt gives Ursa little opportunity to Enrage.
Additional:
* Ursa has no way to clear illusions quickly, making him vulnerable to Chaos bolt and Phantasm combo.
* Reality Rift can quickly relocate or reinitiate on Ursa once the duration of Enrage is over.
* Phantasm can be used to dispel Earthshock's slow. Manta Style is another item that counter Ursa greatly.
* Ursa has low mobility, once jumped on by Reality Rift, Ursa struggles to escape.
Brewmaster
* The three Primal Split brewlings all attacking Templar Assassin at once will remove her 
Refraction quickly, especially with Fire's Permanent Immolation.
* Templar Assassin has no way to stop Brewmaster from using Primal Split by herself, and may get unlucky and miss her 
Meld if trying to burst him during her ally's disable.
Chaos Knight
* Refraction for Templar Asassin can't protect against Chaos Knight typical burst damage with Chaos Strike combinated Chaos Bolt stunned and illusions Phantasm and Manta Style.
* Either illusions for Chaos Knight Phantasm or Manta Style can dispells after Psionic Trap activated slow movement speed or Trap silence upgrade Aghanim's Shard.
* Chaos Knight items 
Assault Cuirass and abilities Reality Rift can easily reduced armor for Templar Asassin's.
Brewmaster
* Brewmaster can use Cyclone to disable Huskar's healer for much longer than most other heroes can, to make Huskar vulnerable.
* Huskar has no way to stop Brewmaster from using Primal Split by himself, but can cut a good amount of his high health away if Huskar's team wants to burst Brewmaster down during a different disable.
Chaos Knight
* Huskar's low armor and movement speed make an easy target for Chaos Knight to initiate on with Reality Rift and Chaos Bolt.
* Beside 
Inner Fire, Huskar has no reliable area of effect ability to clear Phantasm illusions.
* Huskar likes to fight at low health to benefit from his 
Berserker's Blood, thus vulnerable to Chaos Knight's high burst physical damage.
Additional:
* Chaos Bolt can stun Huskar when he jump in with 
Life break, giving 4 seconds maximum for Chaos Knight to deliver a beatdown.
* Reality Rift further reduces Huskar's low armor, boosting Chaos Knight's damage even more.
* Berserker's Blood offer no protection against Chaos Strike, which deal physical damage.
* Phantasm can be used to dispel the disarm from Inner Fire.
* Although Huskar can use this to disarm the illusion instead, buying himself some times.
Brewmaster
* Brewmaster can make the Spirit Bear a much smaller threat with Cinder Brew.
* Cyclone removes the bear from a fight so that his team can easily focus on the hero.
* While most heroes would be worn down by a Spirit Bear 
Radiance in the time it takes to kill Lone Druid, Brewmaster is protected in Primal Split.
Chaos Knight
* Reality Rift lets Chaos Knight bypass the Spirit Bear and jump onto Lone Druid.
* The Spirit Bear's lack of scaling means it dies quickly to Chaos Knight during the late-game.
Brewmaster
* Brewmaster with 
Primal Split
* 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
Chaos Knight
* Phantasm removes 
Glimpse and dispels 
Thunder Strike. Additionally, the Phantasm illusions make it difficult to use Glimpse and Thunder Strike on the real Chaos Knight.
* Disruptor's lack of mobility, combined with his lack of innate defense, sets him up for a Reality Rift and a beatdown by Chaos Knight and his illusions.
Brewmaster
* In general, Brewmaster's Cinder Brew and Thunder Clap makes him good against physical damage carries: 
Ursa, 
Clinkz, Faceless Void, Troll Warlord, Templar Assassin, Phantom Assassin.
Additional:
* 
Thunder Clap and 
Drunken Brawler prevent Faceless Void from maximising his damage potential in fights.
* 
Cyclone disables Faceless Void during Chronosphere or in general.
Chaos Knight
* Faceless Void's lack of strong area-of-effect spells makes it difficult for him to fight against Chaos Knight and his Phantasms.
* From a safe distance and if not caught, Chaos Knight can use Reality Rift to pull Faceless Void out of the 
Chronosphere which combined with Chaos Bolt can expose him to being bursted down by Chaos Knight's team before Void even succeeds to escape with 
Time Walk.
Brewmaster
* Heroes with area dispel can kill multiple skeletons at once: Brewmaster, 
Oracle.
Chaos Knight
* Phantasm gives Chaos Knight a significant advantage against single-target damage dealers: Lifestealer, Wraith King, 
Night Stalker, Troll Warlord.
Additional:
* Wraith King has no form of AoE to clear Chaos Knight's illusions from Phantasm.
* Wraith King is very vulnerable if he reincarnates in the middle of his illusions.
Brewmaster
* In general, Brewmaster's Cinder Brew and Thunder Clap makes him good against physical damage carries: Ursa, Clinkz, Faceless Void, Troll Warlord, Templar Assassin, Phantom Assassin.
Chaos Knight
* Phantasm gives Chaos Knight a significant advantage against single-target damage dealers: Lifestealer, Wraith King, Night Stalker, Troll Warlord.
Additional:
* Chaos Knight's tanky illusions easily take advantage of Troll Warlord's lack of AoE damage.
* Chaos Bolt can stun Troll for up to 4 seconds and Reality Rift prevents Troll Warlord from chasing down foes.
* Phantasm increases Chaos Knight's physical damage output up to 4 times and can easily kill Troll Warlord before he has a chance to use Battle Trance or a Black King Bar.
Brewmaster
* In general, Brewmaster's Cinder Brew and Thunder Clap makes him good against physical damage carries: Ursa, Clinkz, Faceless Void, Troll Warlord, Templar Assassin, Phantom Assassin.
Chaos Knight
* Heroes with illusions and summons can be hard for Phantom Assassin to deal with, as she lacks any AoE abilities to deal with them without items: Broodmother, Phantom Lancer, Chaos Knight, Lycan, Naga Siren, Shadow Shaman, Visage, Nature's Prophet, Terrorblade, Warlock, Wraith King.
Chaos Knight
* Chaos Bolt and Reality Rift makes Tiny's low mobility non existent.
* Chaos Strike means Chaos Knight will most likely survive longer in a duel between the two because Tiny has much lower attack speed.
* Chaos Knight has a 3.2 strength growth, making him one of the most tanky heroes and a very difficult target for Tiny to burst.
Chaos Knight
* Phantasm's illusions make it difficult to land 
Meat Hook and 
Dismember.
* Chaos Bolt is a comparatively low cooldown tool to interrupt Dismember.
* Chaos Strike's lifesteal offsets 
Rot's damage.
Additional:
* Unlike any other illusion heroes, Chaos Knight is the worst target for Pudge to hook as it will definitely backfire him.
* Phantasm are significantly tankier than most illusion and deal full damage, which will quickly kill Pudge due to his low armor.
* it becomes worse if pudge is affected with Reality Rift, which reduces his already abysmal base armor even lower.
* Low movement speed and low mobility means Pudge will struggle to escape or outrun Chaos Knight in most cases.
Chaos Knight
* While 
Blade Fury is on cooldown, Juggernaut can be easily killed by a standard Chaos Bolt & Reality Rift combo.
* Phantasm illusions can tank Omnislash.
Chaos Knight
* Razor has no way to deal with Chaos Knight's multiple illusions from Phantasm.
Chaos Knight
* Sniper is very fragile, along with his low movement speed, make an exceptionally easy target for Chaos Knight to initiate on.
* Sniper has no innate ability to deal with Phantasm or escape a Reality Rift and Chaos Bolt combo.
* In most cases, Sniper likes to stay far in the backline to deal damage, thus he is vulnerable if Chaos Knight manages to jump in the back line, which will usually spell a quick end for Sniper.
Chaos Knight
* Life Drain does not instantly kill the illusions from Phantasm
* Chaos Bolt and Reality Rift can easily interrupt the channeling from Life Drain.
* Reality Rift makes it harder for Pugna to keep his distance between Chaos Knight.
* Nether Ward barely deals any significant damage on Chaos Knight as Chaos Knight's abilities do not cost a lot of mana
* The overwhelming damage of Chaos Knight and his illusions will do a quick work on Pugna's poor HP pool, or safely remove the Nether Ward from the battlefield.
Chaos Knight
* Level 20 talent allows Reality Rift to bypass spell immunity provided by 
Rage, thus negating the advantage Lifestealer has in his kit.
* The fact that Lifestealer lacks wave clearing and reliable lockdown makes it difficult to fight Chaos Knight's illusions.
* 
Feast is largely negated by Chaos Knight's high burst damage from Chaos Strike.
Additional:
* Chaos Strike is a strong burst damage passive that allows Chaos Knight to stand up and even survive Lifestealer's attacks. Level 20 Talent: Reality Rift Pierces Spell Immunity allows him to burst down Lifestealer even while he is in Rage.
* Lifestealer's single-target nature will struggle against Chaos Knight's Phantasm illusions and will be forced to itemize for them.
Chaos Knight
* 
Dark Pact is minimally effective against Phantasm illusions, and Slark lacks area damage otherwise.
* 
Pounce can be counteracted by Reality Rift.
* Slark is naturally frail and dies quickly to Chaos Knight's burst damage before he can build 
Essence Shift stacks.
* Be aware, however, that 
Shadow Dance can make Slark hard to kill as he can't be targeted during its duration.
Additional:
* Phantasms have enough health to survive Dark Pact, and Slark has no other source of AoE damage to deal with them.
Chaos Knight
* Phantasm dispels Ignite and makes targeting the real Chaos Knight much harder.
Chaos Knight
* Phantasm dispels 
Track, and the illusions make it difficult to Track the real Chaos Knight.
* Bounty Hunter is fragile and can easily be killed by Chaos Knight and Phantasm's illusions.
Brewmaster
* Primal Split makes Brewmaster invulnerable for the duration, rendering effects of Cold Feet and Ice Blast useless.
* 
Dispel Magic can dispel Cold Feet from allies.
* Brewmaster can easily run Ancient Apparition down with the slow from Thunder Clap and 
Cinder Brew.
Brewmaster
* {U:Earth} has passive 
Spell Immunity, allowing him to walk into the Echo Stomp radius to stun Elder Titan with his Hurl Boulder.
* {U:Storm}'s Cyclone can cancel the channeling of Echo Stomp and take Elder Titan out of the fight for {show:A|Storm|Cyclone|value2} seconds.
Brewmaster
* Cyclone from Storm in Primal Split can waste Nyx's Spiked Carapace, since its duration is shorter than the Cyclone's.
Brewmaster
* Brewmaster can waste a large portion of Lycan's ultimate by putting him in Cyclone.
* Lycan has no way to stop Brewmaster from using Primal Split by himself.
* Lycan's team often tries to push towers as a group, and Brewmaster excels at winning teamfights while trying to defend a tower.
Chaos Knight
* Chaos Knight's high health pool makes him resistant to Zeus' burst damage. Phantasm can dispel 
Veil of Discord, a typical item purchased by Zeus.
* Zeus is easily overwhelmed by Chaos Knight's strong illusions, as Arc Lightning is not enough to kill them fast enough to have any impact.
* Zeus' low base armor makes him extremely vulnerable to Chaos Knight's high damage output and armor reduction.
Chaos Knight
* Chaos Knight can dispel Flux with Phantasm.
* Chaos Knight can use Reality Rift to pull Arc Warden out of Magnetic Field.
* Once Chaos Knight jumps on Arc Warden with Reality Rift, Arc Warden will struggle to escape due to low mobility and lack of stun.
Chaos Knight
* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, Beastmaster, Bloodseeker, Clockwerk, Doom, Shadow Shaman.
Chaos Knight
* Unlike with other heroes who can summon illusions of themselves, Terrorblade's illusions from 
Conjure Image have different colors than other illusions which can be seen even by enemy team, which can also make Terrorblade weak even against heroes he naturally counters: Bane, Lifestealer, 
Spectre, Chaos Knight, 
Spirit Breaker, 
Sniper. Terrorblade's only solution to counter this problem is to get Manta Style as quickly as possible.
Chaos Knight
* Innately fragile heroes will die almost instantly to Reality Rift while Chaos Knight has illusions active: Drow Ranger, Bane, 
Necrophos, 
Crystal Maiden.
Additional:
* Reality Rift will disable Drow Ranger's Marksmanship, along with Chaos Bolt he can keep her locked for enough time to be killed.
Chaos Knight
* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, Beastmaster, Bloodseeker, Clockwerk, Doom, Shadow Shaman.
Chaos Knight
* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, Beastmaster, Bloodseeker, Clockwerk, Doom, Shadow Shaman.
Chaos Knight
* Chaos Knight, Lone Druid, 
Meepo and 
Arc Warden can be hard targets since Shadow Demon's spells are ill-suited to fight many enemies at once.
Chaos Knight
* 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.
Chaos Knight
* Heroes with illusion and clone abilities may confuse Bloodseeker, causing him to waste time in fights: Phantom Lancer, Chaos Knight, Arc Warden
Chaos Knight
* Warlock is a very strong hero when positioned correctly, and his long cast range helps him with this. However, some Heroes might disrupt or sneakily pass through his allies and deal with him, preventing him from doing his job. Such heroes include Chaos Knight, Spirit Breaker, Riki, and more.
Brewmaster
* In general, Brewmaster's Cinder Brew and Thunder Clap makes him good against physical damage carries: Ursa, Clinkz, Faceless Void, Troll Warlord, Templar Assassin, Phantom Assassin.
Chaos Knight
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Chaos Knight
* Chaos Knight's multiple illusions from Phantasm can destroy Undying, as Soul Rip can't offset the damage from the high amount of damage from his illusions.
Brewmaster
* Heroes who produce many summons will have a hard time against Storm's Dispel Magic during teamfight: Broodmother, Enigma, Nature's Prophet.
Chaos Knight
* Phantasm gives Chaos Knight a significant advantage against single-target damage dealers: Lifestealer, Wraith King, Night Stalker, Troll Warlord.
Additional:
* Chaos Bolt can stun Night Stalker outside of Crippling Fears relatively small radius.
* Reality Rift is a great way to force Night Stalker to fight Chaos Knight, a hero with massive health and damage output. It also forces Night Stalker's Crippling Fear off his primary target.
* Night Stalker doesn't have a lot of ways to deal with multiple targets, which makes him vulnerable to Phantasm illusions unless Night Stalker buys Aghanim's Scepter.
Chaos Knight
* Heroes who relies on illusions and summons (Beastmaster, Chaos Knight, etc.).
Chaos Knight
* Illusion and heroes with summons are difficult to kill with Chen's single-target offensive spells: Terrorblade, Phantom Lancer, Chaos Knight, Broodmother, Naga Siren, Lycan, Visage, Beastmaster, Warlock, Wraith King. And even though Chen can convert enemy summons with Holy Persuasion, their much greater numbers will often overwhelm Chen and his creeps.
Chaos Knight
* Heroes that can overwhelm Visage by sheer number like Chaos Knight, Meepo, Terrorblade and Phantom Lancer.
Chaos Knight
* Heroes with Attack speed decreasing skills: 
Jakiro, 
Viper 
Lich
Chaos Knight
* As Viper focuses on single-target damage, he has trouble fighting off Phantasm illusions.
* Reality Rift counteracts Viper's slows and reduces his already low durability against physical damage.
Additional:
* Viper has no response to the standard initiation combo of Reality Rift into Chaos Bolt.
* Phantasm and Chaos Strike can eliminate Viper almost instantly with it's damage output.
* Besides Nethertoxin, Viper has no other ways of dealing with Phantasm.
Chaos Knight
* 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.
Chaos Knight
* Innately fragile heroes will die almost instantly to Reality Rift while Chaos Knight has illusions active: Drow Ranger, Bane, Necrophos, Crystal Maiden.
Chaos Knight
* 
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.
Brewmaster
* Cinder Brew and Drunken Brawler makes it hard for Monkey King to stack Jingu Mastery.
* Cyclone can remove Monkey king for 6 seconds if his allies lack dispels.
* Dispel Magic can dispel Jingu Mastery's bonuses.
Chaos Knight
* Illusions and summons are double-edge sword type of matchup for Luna. 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).
Chaos Knight
* 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.
Chaos Knight
* 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.
Brewmaster
* {U:Storm} can use Cyclone on Abaddon when he activates Borrowed Time, wasting its duration.
* Drunken Brawler and Thunder Clap hinder Abaddon from applying Curse of Avernus' silence on him.
Additional:
* Dispel Magic can remove Abaddon's Aphotic Shield or 
Curse of Avernus on an allied hero.
* Cyclone's lengthy duration wastes much of Borrowed Time's duration.
Chaos Knight
* 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.
Chaos Knight
* Innately fragile heroes will die almost instantly to Reality Rift while Chaos Knight has illusions active: Drow Ranger, Bane, Necrophos, Crystal Maiden.
Chaos Knight
* 
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.
Brewmaster
* Dispel Magic from {U:Storm} instantly removes Heavenly Grace and Guardian Angel from Omniknight's allies in its radius of effect.
Chaos Knight
* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother
Brewmaster
* Heroes who produce many summons will have a hard time against Storm's Dispel Magic during teamfight: Broodmother, Enigma, Nature's Prophet.
Brewmaster
* Outworld Destroyer's pure damage will mop up Primal Split's units very quickly.
Chaos Knight
* Most Illusion based heroes (like
Chaos Knight and 
Terrorblade) can't use their illusion beneficially against Sanity's Eclipse's high AoE burst damage.