* The percentage-based primary-attribute reduction effect of Whirling Death can be devastating for Pudge due to his high strength gain through Flesh Heap.
* Reactive Armor's health regeneration and common itemization for magic resistance and durability make Timbersaw a poor target for Pudge.
* Timber Chain's high mobility makes Timbersaw difficult to lockdown for Pudge, given he only has one reliable disable.

* 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.

* Timber Chain can kite Troll Warlord extremely effectively.
* Whirling Death and Chakram deals lots of damage to Troll Warlord.
* Reactive Armor makes Timbersaw extremely resilient to Troll's attack damage and extreme attack speed, especially during Battle Trance.

* 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.

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

* Razor deals mostly physical damage towards the later game, and Timbersaw is also very mobile, making him a difficult kill to earn.
* Timbersaw rarely resorts to attacks, thus does not suffer when his damage is stolen with Static Link.

* Reactive Armor helps Timbersaw sustain harassment from Stifling Dagger, as well as ganking attempts.
* Phantom Assassin is a hero with moderate HP pool, and usually appears in the front line of battle. Because Blur does nothing against spells, she is vulnerable to Timbersaw's skills.
* Timbersaw can easily escape from Phantom Assassin thanks to his Timber Chain.
Additional:
* Reactive Armor helps Timbersaw sustain harassment from Stifling Dagger.
* Phantom Assassin has a moderate health pool and usually appears in the front line of battle, making her vulnerable to Timbersaw's magic burst.
* Timbersaw can easily escape from Phantom Assassin thanks to his Timber Chain.

* Heroes with illusions and summons can be hard for Phantom Assassin to deal with, as she lacks any AoE abilities to deal with them: Broodmother, Phantom Lancer, Chaos Knight.

* With Timber Chain, Timbersaw can slow, catch up with, or escape from Chen and his creeps.
* Chakram can clear Chen's creeps and slow him.
* Attacks from multiple creeps quickly build Reactive Armor stacks.

* 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. However, Chen can convert enemy summons with Holy Persuasion, as long as they don't bunch up.

* 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.

* Timbersaw: Lone Druid will have a hard time dealing with Timbersaw due to his tankiness and high Armor from Reactive Armor

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

* Reactive Armor will quickly stack up from Familiar attacks, making Timbersaw hard to kill.
* Visage's low mobility makes it easy for Timbersaw to line up his abilities.

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

* Reactive Armor is very effective against Beastmaster's summons during laning stage and entire game.
* Timbersaw can quickly clear Beastmaster's summons with his nukes.

* Timbersaw can use Chakram as a scouting tool to find Slark if he tries to Pounce into the trees.
* None of Timbersaw's abilities require a target to be cast, allowing him to hit Slark inside Shadow Dance.
* Reactive Armor can be effective protection against a Slark who attacks quickly, since the strong armor and health regen cannot be stolen by Essence Shift.
* Timber Chain makes Timbersaw very mobile, meaning he is among the very few heroes who can actually give chase to a fleeing Slark.

* 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.

* Reactive Armor makes Timbersaw very effective against heroes that control a lot of units, such as Broodmother, Lycan and Undying.

* 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.

* All three of Timbersaw’s spells give him an easy way out of Sprout, and can also destroy nearby trees so Prophet can’t spawn Treants.
* If Prophet tries to escape with a self Sprout/Teleport, Timbersaw can easily cut down any and all trees to get to him and deal increased Whirling Death damage as well. Chakram heavily discourages teleports.
* Timbersaw is quite well suited to clearing massive waves of Treants almost instantly with all of his AoE pure damage spells, giving immense amounts of farm. In addition, the Treants can max out Reactive Armor quite quickly.
* Prophet’s usual heavy autoattack build doesn’t do much against Reactive Armor.
Additional:
* Timbersaw can easily cut down trees from Sprout, making it very difficult for Nature's Prophet to teleport away or trap enemies.
* Timbersaw's abilities quickly clear out treants.
* Reactive Armor negates most of the damage of Nature's Prophet's treants, and Timbersaw can often allow himself to be attacked in order to heal himself.

* Chaos Knight's Level 20 Talent: Reality Rift Pierces Spell Immunity allows for quick bursting down of Lifestealer during his Rage.
* Phantasm dispels Open Wounds.
* Lifestealer has no way of dealing with Chaos Knight's illusions.

* Timbersaw can take down Terrorblade's illusions with his area damage burst.
* Reactive Armor plus another armor item reduce much of Terrorblade's damage.
Additional:
* Timbersaw's spell combos all deal magical and pure damage, completely ignoring Terrorblade's high base armor and clearing his illusions very quickly due to the AoE damage.
* Reactive Armor negates most of Terrorblade's damage against Timbersaw, and its high health regeneration and armor bonuses can help Timbersaw survive after being Sundered.

* While Chaos Knight can land far away from Rubick due to Telekinesis, it can be counteracted by Reality Rift.
* Phantasm dispels Fade Bolt's damage reduction debuff.
* Rubick is fragile and can easily be killed by Chaos Knight and Phantasm's illusions, before he retaliates.

* Phantasm's illusions can be used to push towers and force Techies to detonate Remote Mines.
* Phantasm's illusions can be used to sweep Proximity Mines and Stasis Traps.
* Chaos Knight can easily kill a lone Techies before they Blast Off!.

* Timbersaw’s reliance on nearby trees means he’ll usually be close to Hoodwink.
* More significantly, Timbersaw's tree destroying abilities cut off Hoodwink's escape options, passive and easily foil Acorn Shot/Bushwhack combos.
* While channeling her ultimate, Timbersaw can simply sit his Chakram on top of her and unleash his full combo, forcing her to cancel and disengage.
* Timber Chain can be used to dodge Hoodwink’s ultimate.

* Reality Rift will disable Drow Ranger's Marksmanship, along with Chaos Bolt he can keep her locked for enough time to be killed.
* Phantasm's illusions are hard for Drow Ranger to deal with as she lacks of AoE damage.

* 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 struggles to escape due to low mobility.

* Not only are all of Timbersaw's active abilities capable of cutting down trees, but Whirling Death and Timber Chain also require it to be effective, counteracting both Treant Protector's Nature's Guise and Eyes in the Forest abilities.
Additional:
* Timbersaw can use his plethora of tree cutting abilities to level entire sections of the forest, making hiding in the trees more difficult for Treant Protector and his team.
* Timbersaw can easily cut down Treant Protector's Eyes In The Forest once his team has detection. He may even do it unknowingly due to the sheer destructive and chaotic nature of his abilities.

* 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.

* 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.

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

* Reality Rift pulls out Night Stalker while he tries to escape or chase.
* Night Stalker doesn't have a lot of ways to deal with multiple targets, which makes him vulnerable to Phantasm illusions from early to mid game, until Night Stalker buys Aghanim's Scepter.

* 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.

* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.

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

* Heroes that create illusions (such as 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 and the aforementioned 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).

* Chaos Knight with Phantasm
* 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

Additional:
* 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 illusions can overwhelm Huskar, as he has no AoE abilities: Phantom Lancer, Anti-Mage, Arc Warden, Chaos Knight.

* Multiple attackers thanks to illusions: Phantom Lancer, Chaos Knight, Naga Siren (bonus for her Ensnare). Also despite the visual effects, Templar Assassin does not spill damage against illusions or buildings, so she is not a really good hero to clean up illusions.
* Heroes that can quickly deal damage to her, regardless of how weak they are, can easily break through her Refraction:
* Multiple attackers thanks to summoned units or clones: Meepo, Witch Doctor, Lycan, Enigma, Shadow Shaman
* Multiple attackers thanks to illusions: Phantom Lancer, Chaos Knight, Naga Siren (bonus for her Ensnare). Also despite the visual effects, Templar Assassin does not spill damage against illusions or buildings, so she is not a really good hero to clean up illusions.
* Weak damage but high tick rate or persist in a long time: Slark, Gyrocopter, Queen of Pain, Shadow Shaman (Shackles), Pugna

* Heroes who are not easily crippled by Fate's Edict or Fortune's End, such as Timbersaw, or those who can dispel them, such as Phantom Lancer, can kill Oracle unhindered.

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

* 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 your allies and deal with you, preventing you from doing your job. Such heroes include Chaos Knight, Spirit Breaker, Riki, and some others.

* Reactive Armor makes Timbersaw very effective against heroes that control a lot of units, such as Broodmother, Lycan and Undying.

Additional:
* All of Timbersaw's spells deal AoE damage, killing Lycan's summons very quickly.
* Reactive Armor will gain stacks quickly because of Lycan's summons.

* The burst damage from Timbersaw's abilities is more than enough to deal with Enchantress and her creeps.
* Timbersaw doesn't rely on his physical attacks, which makes Untouchable useless against him.
* Timber Chain can close the gap between them and minimize damage from Impetus.
* Be aware, however, that Timber Chain could work against him if used to escape.
* However, Impetus can ignore Reactive Armor if Enchantress is not a primary target for Timbersaw or if he is disabled.

* Because multiple Meepos tend to clump up, they present an easy target for Timbersaw's many area abilities.

* Timbersaw's innate tankiness is very hard to deal with as Naga Siren. Timbersaw's high Pure Damage and spammable AoE nukes can also destroy Naga Siren's illusions very fast.

* Spiderlings deal almost no damage against Reactive armor. They also die quickly from Timbersaw's AoE abilities.
* Broodmother has no mobility ability except the movement speed buff from Spin Web, allowing Timbersaw to easily escape her Incapacitating Bite with Timber Chain.
* Timbersaw's tree-cutting abilities makes it difficult for Broodmother to hide, especially near the edges of the map.
Additional:
* Reactive Armor prevents Broodmother's spiderlings from being able to effectively harass Timbersaw in the lane.
* Timber Chain's high mobility makes Incapacitating Bite's slow irrelevant.
* Timbersaw's abilities can destroy any trees that Broodmother attempts to hide in and his AoE abilities can quickly clear her Spiderlings.

* Whirling Death deals damage as well while reducing 15% of Bristleback's strength, which reduces Bristleback's tankiness.
* Reactive Armor can sustain through multiple Viscous Nasal Goo and Quill Spray stacks.
* Timber Chain makes it hard for Bristleback to slow down Timbersaw with Viscous Nasal Goo.

* Heroes that can close the gap can easily chase her down, such as Timbersaw with Timber Chain and Anti-Mage with Blink.

* Viper has no response to the standard initiation combo of Reality Rift into Chaos Bolt.
* Phantasm can eliminate Viper almost instantly with its damage output.
Additional:
* As Viper focuses on single-target damage, he has trouble fighting off Phantasm illusions.
* Reality Rift counteracts Viper's slows and reduces his durability.

* Timbersaw is often too mobile and durable for Gyrocopter to bring down with his area attacks.

* All Timbersaw's abilities are AOE pure damage and can easily deal with Phantom Lancer's illusions
* Reactive Armor highly negates Phantom Lancer's physical damage, making him having a hard time killing Timbersaw.
Additional:
* Phantom Lancer's lack of burst damage and constant attacks will increase Reactive Armor to max level immediately. Coupled with Timber Chain making escaping from crowds easy, it is almost impossible for Timbersaw to be killed by Phantom Lancer.
* Whirling Death and Chakram can instantly destroy large groups of illusions, negating Phantom Lancer's advantage.Although Phantom Lancer usually builds diffusal blade.It is a problem in late game.

* 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.

* Whirling Death reduces Axe's strength by 15%, making him much less tanky, especially in the early game. It is also stackable.
* Axe's Blade Mail is ineffective against attribute changes, and Timbersaw's mobility with Timber Chain means he can wait out Blade Mail's duration.
* Reactive Armor's armor and regeneration makes it much harder for Axe to finish Timbersaw with Culling Blade.
* Chakram disarms Timbersaw, making Counter Helix less effective.

* Casting Phantasm before a fight minimizes the disruption from Global Silence.
* Because Chaos Knight generally relies on attack damage, Silencer's spells won't be as effective against him.

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

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

* Timbersaw's pure damage will kill Dragon Knight surprisingly fast, especially if he gets caught in a bad position while laning.

* Timbersaw relies on dealing massive amounts of pure damage, making Cold Embrace a good setup for his nukes.
* If he has Reactive Armor stacks, Timbersaw can tank the damage from his allies if he is targeted by Winter's Curse. If he's not the target, Timbersaw's abysmal attack damage will contribute next to nothing when he is cursed to attack an ally.