* The damage over time from Viper's Poison Attack and Viper Strike rapidly wear down Refraction charges, allowing Templar Assassin to be damaged. Additionally, Corrosive Skin causes her attacks to apply damage over time on her as well.
* Nethertoxin is a big threat to Templar Assassin. Her initially low range making it very hard to deal against Nethertoxin in laning phase. At any stage of the game, a Nethertoxin can always force her to undo her Meld.
Additional:
* All of Viper's abilities quickly burn through Refraction charges.
* Templar Assassin's short range, aside from Psi Blades' spill damage, makes her vulnerable to Poison Attack harassment.
* Templar Assassin traditionally forgoes health and armor items for damage. Outside of Black King Bar, Viper will almost always be able to kill her when Refraction is down.

* Nethertoxin disables Bristleback's passive.
* Viper Strike and Poison Attack slow down Bristleback's movement speed so he's unable to get out from Nethertoxin.
Additional:
* Nethertoxin's break removes Bristleback and prevents Warpath from building stacks. Besides losing his eponymous defensive passive, Bristleback also lose his ability to build up damage over lengthy battles.
* Viper can perpetually kite Bristleback with Poison Attack and Viper Strike.

* Eye of the Storm melts Bristleback's armor, and makes him much less tanky.
* Static Link can completely drain Bristleback's bonus damage from Warpath.
Additional:
* Eye of the Storm melts Bristleback's armor, and makes him much less tanky.
* Static Link can completely drain Bristleback's bonus damage from Warpath.

* Razor's Eye of the Storm damage-over-time easily wear off Refraction charges, allowing Templar Assassin to be damaged.
* Static Link empties Templar Assassin's damage output even with the bonus from Refraction, and will keep doing that even if the Razor cannot see her during Meld.
* Plasma Field and Storm Surge can easily strike her during Meld.

* Heroes who can provide True Sight are always credible threats: Slardar, Bounty Hunter, especially Zeus since his Lightning Bolt provides True Sight without the need to detect her beforehand to apply the debuff. So even a late-coming Zeus can easily scout a large area to reveal her, and she cannot purge herself from his sight with the dispel talent.

* Guardian Sprint allows Slardar to outrun Bristleback, even when slowed by Viscous Nasal Goo.
* Corrosive Haze's armor reduction makes Bristleback much less tanky.

* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, Pudge, Bristleback, Mars.

* Icarus Dive allows Phoenix to shrug off the slow from her trap and make an easy escape from her ambush.
* As Templar Assassin relies on her quality-over-quantity bursting attacks to make quick work on fragile target, Fire Spirits' attack speed reduction can cripple her ability to deals any damage during combat. With the debuff applied in early-mid game, a Meld-breaking hit from her is significantly slowed to the point that her target can make a safe distance before she even landed the hit.
* Sun Ray has quick damage tick and will burn through her Refraction in no time.
* Supernova deals damage over time in an incredibly large area, and again with her quality-over-quantity style, she may not be able to attack quickly enough to break through the Phoenix Sun by herself. (not to mention the debuff from Fire Spirits) This can lead to a failed ganking attempt or even a turnaround.
Additional:
* Her Refraction charges can and will be easily burned away by Phoenix's damage over time abilities, and Meld can't protect her from Phoenix's AoE abilities, even without detection.

* Batrider's turn rate slow from Sticky Napalm makes it harder for Bristleback to keep his back towards the enemy.

* Batrider's abilities are designed to deal damage over time, burning through Templar Assassin's layers extremely quickly. Flamebreak applies 7 instances of damage, burning through the entirety of Refraction, and Firefly applies damage on the place, forcing her to either get out of Meld and be attacked or stay in place or be incinerated.
Additional:
* Batrider's DoT damage quickly removes Templar Assassin's Refraction and can damage her during Meld.

* Ion Shell destroys Refraction's protection stacks in short time.
* Surge ignores the massive slow from Psionic Trap.

* Blade Fury's damage over time dispels Refraction almost instantly.
* Juggernaut's high armor allows him to survive for long enough to remove Refraction and threaten her with Omnislash as long as he or his team carries detection.
* Templar Assassin's short attack range makes it difficult for her to target a well-placed healing ward. She cannot splash onto it with Psi Blades.

* Undying's Decay is a dangerous ability against Bristleback, as it makes him more vulnerable and reduces his tankiness.
* Undying's Tombstone together with Flesh Golem can slow Bristleback down significantly.

* The damage block instances of Refraction can be burned down with Ignite.

* Attacks from Boars and Inner Beast will quickly wear down Refraction.
* True Sight provided by Level 3 Necronomicon can see Templar Assassin in Meld.

* Time Dilation prevents Bristleback from spamming his low-cooldown abilities, greatly reducing his damage and effectiveness.
* Chronosphere allows allies to resposition and hit Bristleback from the front, bypassing his defensive bonus from behind.
Additional:
* Time Dilation while Quill Spray and Viscous Nasal Goo are on cooldown will make these abilities unusable for a long time, rendering Bristleback nearly useless.
* Bristleback cannot turn inside the Chronosphere, which makes it easy to attack him from the front, completely bypassing his passive damage reduction.

* Pugna's Decrepify can render Templar Assassin's physical attacks useless.
* Pugna can also cast Life Drain on Templar Assassin, burning her Refraction instances.
* On the other hand, Pugna generally has low health and armor. Use this to your advantage.

* Windranger's Focus Fire tears apart Templar Assassin's refraction very quickly and easily bursts here down due to her low health pool against Windranger's immense attack speed
* Templar Assassin's "Psionic Trap" doesn't slow down Windranger due to her skill Windrun
* Templar Assassin's high damage can also be easily evaded thanks to Windrun's 100% evasion

* Shackles and Mass Serpent Ward instantly destroy Refraction

* Duel makes Bristleback fight Legion Commander face to face, forcing him to take full damage.
* Press the Attack dispels the slow from stacks of Viscous Nasal Goo.
Additional:
* When dueled, Bristleback will have to face Legion head on, not allowing his passive Bristleback to come into effect.

* Shukuchi gets Weaver in front of Bristleback, negating the protection from the Bristleback passive.
* Weaver's mana break talent depletes Bristleback's mana pool, preventing him from spamming abilities.

* 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.

* Bulwark completely negates Quill Spray's physical damage.
Additional:
* Bulwark reduces most of Bristleback's physical damage.
* Mars can knock back Bristleback to prevent him from chasing down allies with Viscous Nasal Goo.

* Infernal Blade deals scaling damage and is useful against high health targets such as Bristleback. With Aghanim's Scepter, it also breaks Bristleback's passive, rendering him more vulnerable.
* Doom disables Bristleback's low cooldown abilities, preventing him from triggering Warpath. Its pure damage also penetrates Bristleback.
Additional:
* Infernal Blade deals scaling damage and is useful against high HP targets such as Bristleback.
* If Doom gets an Aghanim's Scepter, he can disable Bristleback, taking away much of his durability.
* Doom prevents Bristleback from casting his two low cooldown abilities, which then prevents him from utilizing Warpath.

* 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.

* Mana Drain is a headache for Bristleback to deal with during the laning stage, as it denies him the ability to get last hits with Quill Spray.
* Finger of Death deals high damage to Bristleback, and only triggers his passive once.

* Heroes with invisibility will be detected by Thirst when they have low enough health: Bounty Hunter, Templar Assassin, Riki, Clinkz, Weaver, Treant Protector, Nyx Assassin.

* Because Templar Assassin does not have escape potential in lane, any support hero with roaming potential and a Dust of Appearance can be great at shutting her down early game: Earth Spirit, Spirit Breaker, Tusk, Bounty Hunter, Riki, Warlock.

Additional:
* Templar Assassin is dependant on Refraction in teamfights. Because Magnetize deals damage per second and Earth Spirit is even able to refresh the duration of his ultimate he is suitable for wasting Refraction and allowing his team to take her down.

* Heroes that have disposable area-targeted spells can force her to undo her Meld: Leshrac, Puck, Tiny. An experienced Templar Assassin could try to Refraction before Meld so she can tank through those damage without getting her Blink disabled.

* 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

Additional:
* Ensnare disables Lanaya's invisibility and Blink Dagger (a core item on Templar Assassin), and her illusions will break Refraction easily.

* Weak damage but high tick rate or persist in a long time: Slark, Gyrocopter, Queen of Pain, Shadow Shaman (Shackles), Pugna
* 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

* Because Templar Assassin does not have escape potential in lane, any support hero with roaming potential and a Dust of Appearance can be great at shutting her down early game: Earth Spirit, Spirit Breaker, Tusk, Bounty Hunter, Riki, Warlock.

* Weak damage but high tick rate or persist in a long time: Slark, Gyrocopter, Queen of Pain, Shadow Shaman (Shackles), Pugna
* 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

Additional:
* Dark Pact rips through Refraction charges and still steals attributes during Refraction.
* Pounce and Dark Pact will still hit Templar Assassin while she is Melded. Since she cannot move, both abilities will be easy for Slark to land.

* Terrorblade's Sunder is not affected by the Bristleback damage reduction.

* Shadow Demon's Soul Catcher hinders Bristleback's tanking capabilities. Demonic Purge with Aghanim's Scepter disables Bristleback's passive.

* Weak damage but high tick rate or persist in a long time: Slark, Gyrocopter, Queen of Pain, Shadow Shaman (Shackles), Pugna
* 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

* Firestorm will destroy Refraction charges very quickly.
* Firestorm will hit Templar Assassin while Melded.
* Templar Assassin has a hard time maneuvering around Pit of Malice.

* Reaper's Scythe and Heartstopper Aura deal percentage-based damage, ignoring Bristleback's high health.
* Heartstopper Aura's HP removal does not trigger Bristleback's passive.
Additional:
* Heartstopper Aura deals percentage-based damage flagged as HP removal, so it is not reduced by Bristleback, nor does it trigger passive Quill Sprays.
* Reaper's Scythe is very effective against Bristleback not only due to its percentage-based damage, but rather because it first stuns and then deals its damage, allowing Necrophos to position in front of Bristleback in time.

* Windranger's Focus Fire tears apart Templar Assassin's refraction very quickly and easily bursts here down due to her low health pool against Windranger's immense attack speed
* Templar Assassin's "Psionic Trap" doesn't slow down Windranger due to her skill Windrun
* Templar Assassin's high damage can also be easily evaded thanks to Windrun's 100% evasion
Additional:
* Venomous Gale and Plague Wards allow to quickly melt through Refraction charges.
* Both Poison Nova and Venomous Gale hit invisible units, so Meld cannot be used defensively.

* Sinister Gaze forces Bristleback to face Lich, exposing him to damage.
* Frost Shield reduces damage to a single target, counteracting Warpath and Viscous Nasal Goo.
* Lich's plethora of slows make it easy to kite Bristleback.

* Arcane Curse stacks every time Bristleback uses an ability, forcing him to stop spamming his abilities, or take heavy health degeneration.
* Glaives of Wisdom's pure damage cuts through Bristleback's tanky items. also steals intelligence both permanently and temporarily and cause mana issues for Bristleback
* Last Word and Global Silence stops Bristleback from using his abilities altogether.
Additional:
* Glaives of Wisdom deals pure damage, therefore it is not reduced by Bristleback.
* 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 abilitiess, he will begin to lose Warpath charges.

* Swashbuckle quickly burn away Refraction charges.
* Lucky Shot can possibly disrupt Templar Assassin when she is boosted with Refraction.
* Pangolier's abilities which does not need to target and has big area of effect allows him to damage her even during Meld.
* Pangolier's high mobility easily shrug off the slow from Psionic Trap.

* Bristleback's tankiness doesn't help him very much against Fury Swipes in long teamfights.
* With no escape mechanism and a slow movement speed, getting jumped on by Ursa usually spell a quick end for Bristleback in the early game.

* Outworld Devourer's heavy pure damage output penetrates Bristleback's tanky items.
* Sanity's Eclipse only triggers Bristleback's passive once, and deals high damage against Bristleback's low intelligence.

* Phantom's Embrace silences Viscous Nasal Goo and Quill Spray.
* Ink Swell stuns Bristleback and gets allies in position faster with increased movement speed to attack his front, countering his passive ability.