* Heroes that have long silences, such as Night Stalker and Silencer, will prevent Abaddon from saving his allies effectively and disable the active component of Borrowed Time.

* Heroes with low mana pools (eg.Doom andTidehunter) will feel the effects of Silencer's Intelligence Steal far more than others.

* Silencer's Global Silence and Doom's Doom makes Earthshaker temporarily useless.

* Heroes with abilities or items that can silence or disable Anti-Mage for long periods of time will prevent him from Blinking away: Lion, Silencer, Shadow Shaman, Grimstroke, Witch Doctor, Riki, Faceless Void, Skywrath Mage, Puck.

* Lich is heavily reliant on his abilities to contribute to team fights, so be wary of enemies that can Silence: Bloodseeker, Death Prophet, Silencer, Drow Ranger, Skywrath Mage.

* 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.

* 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.

* Global Silence has faster-cast animation than Chronosphere, making Silencer can silence Faceless Void before he can cast Chronosphere.

* 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.

* Zeus' main source of damage is his low cooldown, high damage spells - meaning Last Word and Global Silence will pretty much take him out of the game for the duration.
* Zeus likes to spam his abilities, which makes him vulnerable to Arcane Curse.
* If Zeus dies near Silencer, he will begin to lose intelligence, reducing his mana pool, mana regen, and attack damage. Furthermore, if the game is long and Zeus dies often, the intelligence losses will also reduce his spell damage.
Additional:
* Silencer's Global Silence will render Zeus useless for 6 seconds in a team fight.
* Arcane Curse will punish Zeus for casting spells, which can cause continuous damage to him should he continue to cast spells.
* Last Word can silence Zeus and prevent him from spamming his spells.
* Silencer often builds Orchid Malevolence (or Bloodthorn) which can be used on spell casters like Zeus, forcing him to invest in a Linken's Sphere.

* 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.

* Pugna is very reliant on his abilities for damage which Silencer can take advantage off. But he has to be careful around the Nether Ward as Silencer's abilities cost a lot of mana to use.

* 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.

* Terrorblade is a double-edged sword type of matchup against Silencer. Although Terrorblade is more reliant on direct attacks to be effective, he relies on Sunder to save himself and stay alive and Last Word and Global Silence prevent him from doing that.
* Arcane Curse and Aghanim's Scepter upgraded Last Word help Silencer deal with Terrorblade's illusions from Conjure Image and Manta Style.
* With Last Word Mutes talent, Silencer can not only disable Terrorblade from turning tables with Sunder, but can also prevent him from using Manta Style and Black King Bar, items Terrorblade needs to be effective in teamfights.
* Glaives of Wisdom deals pure damage against the real Terrorblade, bypassing his high base armor.
* Global Silence can silence Terrorblade even if he has Black King Bar active, though bear in mind that Terrorblade can dispel Global Silence with Manta Style and Black King Bar if the Global Silence was activated first.
Additional:
* Silencer is a double-edged sword type of matchup against Terrorblade. Although Terrorblade is more reliant on direct attacks to be effective, he relies on Sunder to save himself and stay alive and Last Word and Global Silence prevent him from doing that.
* Arcane Curse, Glaives of Wisdom upgraded with 2 Glaives of Wisdom Bounces talent and Aghanim's Scepter upgraded Last Word help Silencer deal with Terrorblade's illusions from Conjure Image and Manta Style.
* With Last Word Mutes talent, Silencer can not only disable Terrorblade from turning tables with Sunder, but can also prevent him from using Manta Style and Black King Bar, items Terrorblade needs to be effective in teamfights.
* Glaives of Wisdom deals magical damage against the real Terrorblade, bypassing his high base armor. Later it can be upgraded with 2 Glaives of Wisdom Bounces talent to deal against Terrorblade's illusions. Alternatively, Silencer is a natural Revenant's Brooch wielder, which gives him another way to damaging Terrorblade through his high base armor.
* Global Silence can silence Terrorblade even if he has Black King Bar active, though bear in mind that Terrorblade can dispel Global Silence with Manta Style and Black King Bar if the Global Silence was activated first.

* 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.

* Silencer can reduce Muerta's damage output with his Glaives of Wisdom, and since he commonly buys Revenant's Brooch, he will be able to attack her even through Pierce the Veil.
* Silencer has reliable, long-range silences in Last Word and Global Silence, preventing Muerta from using her spells as effectively.
* As Muerta tends to use her spells, particularly Dead Shot; Arcane Curse is very effective against her as that can punish her for doing so.

* Heroes with abilities that can close the gap can easily kill Muerta: Storm Spirit, Earth Spirit, Ember Spirit, Void Spirit, Lycan, Chaos Knight, Tusk.

* Shadow Demon's main source of damage is his low cooldown, high damage spells - meaning Last Word and Global Silence will pretty much take him out of the game for the duration.
* Shadow Demon likes to spam his abilities, which makes him vulnerable to Arcane Curse.
* If Shadow Demon dies near Silencer, he will lose intelligence, reducing his mana pool, mana regen, and attack damage. Furthermore, if the game is long and Shadow Demon dies often, the intelligence losses will also reduce his spell damage.

* 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.

* Because Warlock's abilities are all active abilities, Silencer can make his impact minimal.
* Arcane Curse prevents Warlock from using his abilities without increasing it's duration, which since all of Warlock's abilities are actives it is very effective against him.
* Last Word can prevent Warlock from casting his Fatal Bonds, Chaotic Offering, and Upheaval combo.
* Global Silence can nullify Warlock's impact in fights by preventing him from casting Fatal Bonds and Chaotic Offering, or by interrupting his Upheaval.

* 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.

* Arcane Curse can effectively discourage Undying from casting his spammable abilities in a team fight, as Undying will have to suffer more damage and the slow due to the penalty duration of Arcane Curse.
* Last Word and Global Silence are able to silence Undying for up to 6 seconds, preventing Undying from gaining strength and healing his ally or himself.

* 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.

* Heroes with silences : Bloodseeker, Riki, Silencer.

* 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.

* Heroes with low mana pools (eg.Doom andTidehunter) will feel the effects of Silencer's Intelligence Steal far more than others.

* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, Beastmaster, Bloodseeker, Clockwerk, Doom, Shadow Shaman.

* Heroes with silence such as Riki, Silencer, or Night Stalker prevents Skywrath Mage from using his spells.

* 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.

* With 4 active abilities, Shadow Shaman is weak against silencing foes such as Silencer, Drow Ranger and Death Prophet.

* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, Beastmaster, Bloodseeker, Clockwerk, Doom, Shadow Shaman.

* Arcane Curse makes it too difficult Lina from using her abilities, preventing her from building up Fiery Soul stacks without causing harm to herself.
* Last Word and Global Silence are great against Lina for the same reason, as well as interrupting her combos and preventing her from casting spells.

* 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.

* Crystal Maiden is squishy, is heavily spell reliant, has low base Intelligence, and is naturally slow, making her an ideal target for Silencer.
* Crystal Maiden's Freezing Field has a similar cooldown to Global Silence, therefore, Freezing Field can almost always be canceled to ruin aggressive Crystal Maiden initiations.

* Innately fragile heroes will die almost instantly to Reality Rift while Chaos Knight has illusions active: Drow Ranger, Bane, Necrophos, Crystal Maiden.

* Razor has no way to deal with Chaos Knight's multiple illusions from Phantasm.

* Glaives of Wisdom's intelligence steal will heavily punish Queen of Pain, as the loss of intelligence means that her mana pool is also reduced, since she is heavily reliant on her abilities to be able to make an impact.
* In the laning stage, Queen of Pain's reliance on spamming Shadow Strike and Scream of Pain will be significantly hindered by Arcane Curse.
* Last Word and Global Silence will render Queen of Pain defenseless unless she has an item/ally to dispel the silence.

* Arcane Curse punishes Necrophos if tries to spam Death Pulse, increasing the duration of the slow and damage taken over time.
* Last Word heavily damages Necrophos and also silence him for a lenghty duration.
* Glaives of Wisdom will reduce temporarily Necrophos intelligence on each hit dealing hindering his ability to spam Death Pulse, also reducing his attack damage and mana pool; dealing increasing amounts of phisical and pure damage each time. Silencer will permanently steal Necrophos intelligence if Necrophos is killed by him or if he dies nears him.
* Global Silence turns Necrophos almost useless for a long time, allowing Silencer and his team to easily dispatch him, since Necrohpos heavily relies on his spells to survive.

* Innately fragile heroes will die almost instantly to Reality Rift while Chaos Knight has illusions active: Drow Ranger, Bane, Necrophos, Crystal Maiden.

* Last Word and Arcane Curse have the range to hit Dark Willow beyond Bramble Maze.
* Global Silence renders Dark Willow useless in teamfights.

* 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.

* 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.

* Phantasm dispels Ignite and makes targeting the real Chaos Knight much harder.

* 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.

* Invoker is heavily dependent on his spells, making him useless during Global Silence, as well as interrupting Invoker during his combo.
* Arcane Curse is particularly deadly, because Invoker will continuously lose health if he keeps invoking and casting new spells.
* Last Word will silence Invoker when he casts Invoke, interrupting his combo.

* Silencer burns easily through her effective HP from Mana Shield, by taking away her intelligence.
* Arcane Curse punishes her repeatedly casting Mystic Snake to keep her mana pool high. He can force her to use Manta Style before he has cast Global Silence and Medusa usually does not want to build Black King Bar.

* Heroes with pure damage can kill Huskar when he inevitably gets low on health: Outworld Destroyer, Silencer.

* Huskar's low armor and movement speed make an easy target for Chaos Knight to initiate on with Reality Rift and Chaos Bolt.
* Other than Inner Fire, Huskar has no reliable area of effect ability to clear Phantasm illusions.
* Huskar likes to stay at low health to benefit from his Berserker's Blood, thus making him 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.

* While Blade Fury is on cooldown, Juggernaut can be easily killed by a standard Chaos Bolt & Reality Rift combo.
* Phantasm illusions can tank Omnislash.

* 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.

* Heroes with silencing abilities that are not blocked by Linken's Sphere, like Puck's Waning Rift, Death Prophet's Silence or Silencer's Global Silence.

* Basically, Heroes that heavily rely on abilities for damage or escape, such as Queen of Pain and Storm Spirit.

Additional:
* Silencer's Intelligence Steal can reduce Storm Spirit's damage output if he gets some kills on laning phase.
* Last Word and Global Silence will make Storm Spirit an easy target.
* Global Silence can be used to prevent Storm Spirit from connecting abilities after a Ball Lightning on his targets.

* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, Beastmaster, Bloodseeker, Clockwerk, Doom, Shadow Shaman.

* Lion is extremely dependent on his abilities. Silences like Silencer's Last Word, magic resistance like Oracle's Fate's Edict, and dispels like Legion Commander's Press the Attack all make his abilities less effective.

* 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, Wraith King.

* 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.

* Heroes with silencing abilities can be particularly deadly when Slark is trying to escape: Silencer, Death Prophet, Puck, Doom.

* 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.

* Heroes with illusion and clone abilities may confuse Bloodseeker, causing him to waste time in fights: Phantom Lancer, Chaos Knight, Arc Warden

* Silences and other types of lockdown that prevent Weaver from using his spells: Silencer, Riki, Lion, Legion Commander, Shadow Shaman, Bane.

* 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.

* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, Beastmaster, Bloodseeker, Clockwerk, Doom, Shadow Shaman.

* Heroes with silences and hard stuns such as Doom, Silencer, and Lion can keep Mirana from Leaping away.

* Heroes who relies on illusions and summons (Beastmaster, Chaos Knight, etc.).

* Silencer can stop Rearm, preventing Tinker from spamming his abilities/items or escaping.
* Tinker heavily relies on his mana pool and has mana issues throughout the entire game and Silencer's intelligence steal does not help with that.
Additional:
* As Tinker relies heavily on his spells to be effective, Last Word and Global Silence will render him largely useless.
* Arcane Curse effectively prevents Tinker from casting spells during its duration, as he will otherwise suffer heavy damage.
* Glaives of Wisdom deal pure damage, which make quick work of fragile heroes like Tinker.
* Silencer's intelligence steal permanently weakens Tinker since he's a hero who requires lots of mana to be effective.

* 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.

* 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.

* Heroes that can overwhelm Visage by sheer number like Chaos Knight, Meepo, Terrorblade and Phantom Lancer.

* Heroes with silence and mana drain abilites, as Ancient Apparition relies entirely on his abilities: Invoker, Silencer, Nyx Assassin, Skywrath Mage, Shadow Shaman, Lion and etc.

* A strong illusion Phantasm) from Chaos Knight can cleared from her's Refraction. Additionally, natural items Manta Style can dispell silence Psionic Trap from Aghanim's Shard.

* Silencer's abilities hamper Windranger's effectiveness in battle, preventing her from comboing abilities and escaping using Windrun.
Additional:
* Glaives of Wisdom's intelligence steal can prove detrimental to Windranger, as she heavily relies on her abilities to be able to make an impact.
* Silencer's abilities hamper Windranger's effectiveness in battle, preventing her from comboing abilities and escaping using Windrun.

* 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.

* Global Silence stops Snapfire's Mortimer Kisses.
* Last Word can prevent Snapfire from casting additional spells.

* Global Silence and Last Word can prevent Ember Spirit from casting Activate Fire Remnant to escape.
* Glaives of Wisdom also provide high pure damage that is not negated by Flame Guard.
* Arcane Curse is also a potent harassing tool in the laneing stage as its cooldown is lower than Flame Guard's.

* Silencer will most likely disrupt an initiation with his ultimate, Global Silence, prevent escape with his Last Word, and if Phoenix happens to die to him (or near him) enough times, he would sap enough of Phoenix's much needed Intelligence to make him a stronger foe and Phoenix with less mana than it already had.

* Silencer's Intelligence Steal will heavily reduce Outworld Destroyer's damage output, particularly from Sanity's Eclipse.
* Last Word and Global Silence will take Outworld Destroyer out of the fight unless he has built Black King Bar.
Additional:
* Silencer's intelligence steal will heavily reduce Outworld Destroyer's damage output, especially if Destroyer dies a lot near Silencer and loses intelligence permanently.
* Global Silence and Last Word will render Outworld Destroyer helpless unless he has an item/ally to dispel silence.

* A well-timed Global Silence prevents Dazzle from saving allies with Shallow Grave or Shadow Wave. Items that could dispel the silence are expensive, and difficult for Dazzle to farm from a support role.
* Arcane Curse and Last Word cause long damage over time, which may outlast Shallow Grave.

* Both Arcane Curse and Last Word punishes casters with spammable spells such as Sand King.
* As a strength caster, Intelligence Steal reduces Sand King's mana pool even more.
* Global Silence silences Sand King, effectively reducing Sand King's initiation and counter-initiation potential. It can also interrupt channeling of Epicenter.

* Timbersaw is heavily reliant on his abilities for damage and escape, allowing Silencer to effectively disable him and make him useless in both team fights and 1v1 scenarios.
Additional:
* Arcane Curse deals repeated stacks of damage to Timbersaw because he relies on constantly using his abilities.
* Glaives of Wisdom deals pure damage and when cast manually, nearby creeps will not attack silencer, making it an effective harassment tool. The intelligence steal is also especially potent against Timbersaw since he often uses up all of his mana throughout the entire game.
* Although Last Word takes a while to trigger, it will break Timbersaw's ability combo and can be used to silence him.
* Global Silence will silence Timbersaw no matter where he is on the map. This can be used to help allies get a kill on him, or prevent Timbersaw from killing someone.

* Arcane Curse stacks every time Bristleback uses an ability, forcing him to stop spamming his abilities, or take heavy health degeneration.
* Glaives of Wisdom steals intelligence both permanently and temporarily, causing mana issues for Bristleback.
* Last Word and Global Silence stops Bristleback from using his abilities altogether.
Additional:
* Bristleback will not be able to cast Viscous Nasal Goo or Quill Spray while silenced, effectively blocking a major part of the hero's damage and preventing Warpath charges from stacking.
* Arcane Curse slows Bristleback down and lasts longer the more abilities he uses. On the other hand, if he doesn't use any abilities, he will begin to lose Warpath charges.

* 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.

* Kunkka relies on his powerful AOE spells to turn the tides of teamfights. He cannot use them while silenced.
* Last Word can mess up Kunkka's ability synergy, silencing him in the middle of his strong combo.
* Global Silence can disable Kunkka's spell casting from anywhere on the map, even if Kunkka is spell immune at the time.

* Sniper is very fragile and has low movement speed, making 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 on him in the back line, which will usually spell a quick end for Sniper.

* Generally strong against lots of spellcaster-themed heroes, Puck fully relies on its skill set and cannot do almost anything when silenced.
* Arcane Curse disables Blink Dagger for quite some time, and is also effective against Puck as it tends to use its spells a lot.
* Glaives of Wisdom can do a lot of damage against Puck due to Puck's low agility gain and armor.
* Last Word can prevent Puck from getting a full combo off, limiting its effectiveness in team fights or ganks.
* Global Silence can take Puck out of fights entirely because of its long-duration silence.

* Like any hero with a channeled spell, Last Word is a counter to it.
* Global Silence goes through spell immunity and prevents Witch Doctor from casting his spells.

* Global Silence takes Omniknight out of the fight completely.
* Glaives of Wisdom are a great harass vs Omniknight during the laning stages of the game, since it doesn't aggro creeps & ignores his high base armor. It deals pure damage, which means it can also go through Guardian Angel.
* Silencer's intelligence steal can also cause Omniknight to falter in the early phases as it reduces his ability to use his spells.

* Arcane Curse can be cast from a long range to put Enigma's Blink Dagger on cooldown.
* Global Silence can interrupt Enigma's Black Hole channeling through Black King Bar and Linken's Sphere, making Silencer one of Enigma's hard counters. But bear in mind that Global Silence can be dispelled with Black King Bar if activated first.
Additional:
* Silencer can easily ruin Enigma's initiation, as Global Silence cancels Black Hole, even through Black King Bar and Linken's Sphere.

* 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.

* 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.

* 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.

* Heroes with illusions and summons can swarm and overwhelm Bane, who has no area abilities to deal with them 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.

* 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.

* Oracle's reliance on spamming his spells can be easily hindered by Silencer's Arcane Curse.
* Last Word and Global Silence negates Oracle's attempt to save his allies with his spells.
* Fate's Edict is useless against Glaives of Wisdom's pure damage.

* 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.