* Tidebringer will deal lots of damage to Alchemist before he builds physical survivability items.
* Torrent and X Marks the Spot can control Alchemist at all stages of the game before he has Black King Bar.
* Ghostship's rum buff will greatly reduce the Alchemist's damage output in teamfights including his Radiance.

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

* Untouchable greatly reduces Chemical Rage's attack speed advantage.

* 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.
Additional:
* Untouchable will significantly slow down Chaos Knight's physical damage with Phantasm.
* Impetus deals double damage to illusions, making it effective against Phantasm.

* Axe can force Alchemist to attack him with Berserker's Call. High attack speed from Chemical Rage will cause Counter Helix to proc multiple times.
* This can get worse if axe has Blade Mail, which then returns all damage to Alchemist himself.
* Axe's abilities can pierce through Black King Bar, which is a common item for Alchemist.
* Berserker's Call grants Axe a huge bonus armor, which greatly counters Alchemist's physical damage for the most part.

* 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.

* Melee heroes that get kited easily have hard times dealing with Puck without any lockdowns, as Puck is one of the most mobile heroes. Heroes like Sven, Lifestealer, Ursa and Alchemist may have problems to get to Puck without proper initiation items. They also lack reliable lockdowns, as their disables are easily avoidable for Puck, or are just a soft disable.

* 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.

* Ember's magic damage build is able to burst down Alchemist due to his low strength gain and Alchemist's normal item pick up.

* 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 struggle to fight back against Sven at any point in the game are at a severe disadvantage: Alchemist, Anti-Mage, Crystal Maiden.

* 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 physical damage output.
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.

* Alchemist has very bad armor and does not build armor items for the large majority of his build, so Jingu Mastery and Wukong's Command can be very deadly.
* Desolator, Sange and Yasha or Diffusal Blade can all be purchased to increase your damage against Alchemist or just to keep your movement speed high enough to match him while Chemical Rage is active.
* Monkey King is an agility hero and scales with armor, so Acid Spray loses it's effectiveness later in the game.

* 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.

* Heroes who rely on burst physical damage are affected by Lucky Shot's disarm: Terrorblade, Sven, Clinkz, Windranger, Alchemist, Dragon Knight, Legion Commander

* 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

* 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.

* 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 long duration.

* 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.

* Cold Embrace protects targets affected by 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 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.

* Ice Blast nullifies the health regeneration granted by Chemical Rage, which Alchemist greatly relies on to stay alive in battle.
* Alchemist tends to build Armlet of Mordiggian which can be deadly during Ice Blast.
Additional:
* Ice Blast cancels out Chemical Rage's rapid health regeneration. It can also take advantage of Alchemist's Armlet of Mordiggian toggling, as it will make HP drain insanely fast, essentially killing the bearer in no time.

* Black Hole usually catches Chaos Knight with all his illusions.
* Midnight Pulse deals damage based on current health, quickly killing Phantasm 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 Phantasms early on, and can still deal a lot of damage to them late game, revealing the real Chaos Knight.

* Reaper's Scythe can kill Alchemist before Chemical Rage has the time to heal him.
* Ghost Shroud can prevent Alchemist from attacking Necrophos, as well as make him immune to Acid Spray and Unstable Concoction damage.
* Heartstopper Aura will do damage as long as Necrophos is alive based on health percentage, which is a problem for a strength hero such as Alchemist.

* 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.

* 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.

* 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 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

* Quas-Exort Invoker can win the mid lane easily against Alchemist because Quas regeneration will nullify Acid Spray's damage over time and Exort damage bonus will allow Invoker to out last hit Alchemist.

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

* Corrosive Haze followed by Slithereen Crush takes advantage of Alchemist's main weakness, being physical damage before he has the change to improve his surviability with items.
* Bash of the Deep will deal lots of damage during the laning phase.

* 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 harder 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.

* 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.

* 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.

* 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.

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

* Quill Spray quickly destroys Chaos Knight's Phantasms.

* 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.

* 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 thanks to his Atrophy Aura, and will also 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.

* 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 thanks to his Atrophy Aura, and will also 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.

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

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

* Heroes who are melee but cannot fight back against Eclipse will really struggle with Luna: Monkey King, Alchemist, Timbersaw.

* 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).

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

Additional:
* 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.

* Most 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.

* Clinkz can use Burning Army in teamfights which will cause a problem for Alchemist.

* 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.

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

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

* 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.

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

* 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.

* Alchemist is a well-known Radiance carrier among other auras your illusions will benefit from. They also get the extra move speed and reduced base attack time from his Chemical Rage, and it's even better if you can catch him as his own rage is about to expire.
* Disruption will buy enough time for all allies to retreat when Alchemist starts to activate Unstable Concoction.

* Skywrath Mage can easily harass Alchemist in the laning phase with multiple Arcane Bolts. Additionally, if Alchemist is in the process of throwing an Unstable Concoction, and has no way to dispel Ancient Seal, the self stun becomes an easy set up for Mystic Flare.
* Caution, however, as a decently farmed Alchemist with {Item ID:Radiance} and {Item ID:Manta Style} can easily send illusions to harass and force Skywrath Mage out.

* 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.
* Phantom Lancer often builds a Manta Style, which can be used to disjoint Chaos Bolt or dispel Reality Rift.
* Doppelganger can be used to dodge Chaos Bolt.
* Diffusal Blade, another common item on Phantom Lancer, can quickly drain Chaos Knight's low mana pool, leaving him unable to cast spells.

* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.

* Heroes with Attack speed decreasing skills: Jakiro, Viper Lich

* Doom can disable Chemical Rage's increased healing, rendering Alchemist helpless against Doom.
* Attacks from Infernal Blade can deal serious damage to Alchemist as it deals damage based on the hero's maximum health.

* Pugna's Decrepify makes sure that either Alchemist is unable to hit anyone while also being slowed and susceptible to magical damage, or can protect an ally from physical attacks. Besides, Pugna can push early on, when Alchemist is not strong enough to repel it, so by the time Alchemist comes online, he might be forced to sit in base.

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

* Heroes without an escape mechanism: Shadow Fiend, Alchemist

Additional:
* Chemical Rage will rarely save Alchemist against Ursa's Fury Swipes.
* Enrage allows Ursa to both be a threat to Alchemist and avoid his over time damage.

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

* Heroes who rely on physical damage output to be effective will fare badly against Muerta's Pierce the Veil: Phantom Assassin, Terrorblade, Drow Ranger, Lifestealer, Anti-Mage, Alchemist, Lycan, Clinkz, Sniper.

* Sprout is good for trapping melee carries with no escape abilities: Sven, Alchemist, Lifestealer etc.

* Shadow Dance allows Slark to not be targeted by Unstable Concoction, making Alchemist stun himself and making himself vulnerable to the enemy.
* Dark Pact also allows him to just purge off the stun if timed correctly.
* Essence Shift will steal stats over long durations at a time should Alchemist lack the damage to kill Slark.

* Alchemist's reliance on fast attack speed to do single-target damage makes him vulnerable to Static Link. It also goes through Black King Bar, which is a standard item on Alchemist.
* Eye of the Storm is great against high health strength heroes as it reduces their survivability to physical damage.
* Razor has early lane push to counter Acid Spray.

* 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.

* 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.

* Alchemist likes to farm fast and be ahead, unfortunately Lone Druid likes to do the same by taking towers.
* Acid Spray will never prove a threat to Lone Druid or his Spirit Bear.
* Chemical Rage may not prove so useful once Lone Druid procs entangled keeping him in place.
* Monkey King Bar is a very good choice on Lone Druid's Spirit Bear and it directly counters any potential Radiance from Alchemist.
* Assault Cuirass is another very good Spirit Bear item that further makes Alchemist vulnerable to physical damage, which is all Lone Druid does.
* Alchemist is not the kind of hero who wants to go on single target summon units, by the time he has killed the Spirit Bear his teammates might had already been slayed by his teammates. Not to mention Lone Druid can just resummon it, even if he is successful.

* Visage can quickly kill heroes with low to medium base armor and no innate escape mechanism. Examples include Alchemist, Crystal Maiden and Zeus.

* Feast is good against high health strength heroes such as Alchemist.
* Rage allows Lifestealer to not be targetable by Unstable Concoction, possibly making Alchemist stun himself.