* 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 overtime 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 the 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.

* The slow applied from Corrosive Skin offsets the movement speed bonus granted by Scorched Earth and the tick-based damage from Infernal Blade and Doom will continually slow Doom down. This allows Viper, much like Sniper, to 'kite' Doom and keep him at a safe distance between the two. Additionally, Corrosive Skin applies an attack-speed slow which is fairly crippling to a hero such as Doom that, naturally, has a high base attack-time, poor agility gain and builds little attack-speed items.
* Since Doom does not disable auto-cast abilities, Viper's Poison Attack will continue to work. Doom may find it hard to close the distance between himself and Viper, and thusly difficult to effectively lockdown and continually deal damage through his abilities.

* Phantom Lancer's illusions destroy Refraction charges very quickly.

* Phantom Lancer's illusions can make it difficult to Doom the original. Should Doom figure out the original hero, the illusions can make it difficult to cast any abilities, as their hitboxes can be used to body-block the Phantom Lancer.
* Phantom Lancer is an ideal Diffusal Blade carrier. With it, he can quite easily deplete Doom's already poor mana pool, potentially making him unable to cast his abilities to escape, retaliate or heal.
* Doom lacks any effective ability to clear waves of creeps and illusions, as the vast majority of his abilities are single-target. Without an answer, Doom may find it difficult to deal with Phantom Lancer's presence.

* Many physical-only single-target heroes like Lifestealer, Sven, Wraith King, Phantom Assassin, Templar Assassin can have their damage mitigated by Cold Embrace.

* Heroes with the ability to heal allies, or those with good defensive abilities: Chen, Dazzle, Io, Oracle, Omniknight, Witch Doctor, Winter Wyvern, Abaddon, etc.

* 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), Jakiro, Pugna

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

* Terrorblade is one of the strongest carries in the late game, due to his resilience against physical damage, which can be a problem for almost every strong burst physical damage carries, such as Phantom Assassin and Templar Assassin.

* Terrorblade can use Sunder to save his allies who are Doomed.

* Heroes who just want to farm and avoid Lone Druid early will find it very hard to do so when he starts knocking on towers: Templar Assassin, Phantom Assassin, Ember Spirit, Morphling.

* Lone Druid is essentially two heroes. Dooming one over the other still leaves Lone Druid or his bear able to do their job during a fight. Additionally, Lone Druid is not hindered as much as other heroes by the silence and mute of Doom since the hero relies more on attacks than abilities.
Additional:
* Doom will be very hestitant to use Doom on the Spirit Bear, and using it on Lone Druid himself will not stop the bear from attacking him especially if True Form has already been used.
* Devour does not work on the Spirit Bear and pushes the lane so Lone Druid can safely farm under tower.

* 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.

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

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

* Attacks from Boars and the attack speed boost from Inner Beast will quickly wear down Refraction.

* All of Jakiro's active skills can be targeted on an area, which is effective at forcing Templar Assassin to move should she Meld away.
* Many of Jakiro's spells utilize damage-over-time mechanics, which makes it easy to strip away layers of Refraction.

* 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.
Additional:
* Phoenix's abilities target and deals damage over time, making them a threat against Meld and Refraction. His abilities' nature makes them pretty hard to correctly land on the target, but that is not a problem against a Templar Assassin that needs to stand still during Meld.
* 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 travel a safe distance before she even lands the hit.
* Sun Ray has a 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.

* Due to Doom's naturally high health, strength gain and common itemization for durability, Heartstopper Aura is particularly effective. The health loss is also large enough that, throughout all stages of the game, the aura effectively neuters the health regeneration granted by Devour.
* Necrophos can help to keep both himself and his allies alive during Doom through his natural regeneration granted by Heartstopper Aura (which is not disabled by Doom), or in the case of an ally, through his Death Pulse. Additionally, Necrophos is an ideal Mekansm carrier. Should one be bought, kills against Necrophos' team can be difficult to secure due to the damage-over-time nature of Doom and his abilities.
* Doom typically wants to be a hero that soaks attention from the enemy team and takes the role of an initiator and disabler. As such, Doom is an ideal target for Reaper's Scythe, as it is likely Doom will be at the fore-front of any fight.

* 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.

* Sand King can quickly remove her Refraction with his Sand Storm.
* Once Refraction is down, she is very vulnerable to Epicenter's high magic damage.

* Pulse Nova can easily burn Templar Assassin's Refraction charges quickly, and can also hit her with her Meld.

* 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.

* Shackles and Mass Serpent Ward instantly destroy Refraction

* Windranger's Focus Fire tears apart Templar Assassin's refraction very quickly and easily bursts her 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.

* Batrider's DoT damage quickly removes Templar Assassin's Refraction and can damage her during Meld.
Additional:
* 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.
* Flaming Lasso pierces Black King Bar and rendering Templar Assassin helpless unless there are allies helping her.

* Bushwhack can tear through Refraction as it does multiple intervals of damage.

* 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.

* The health regeneration and bonus movespeed from Chemical Rage allows Alchemist to survive through Doom very easily.
* Doom's low armor makes him weak against Alchemist's high physical damage output.
Additional:
* Chemical Rage out-heals Doom to a large degree throughout all stages of the game. Should Alchemist be chemically enraged before being Doomed, Alchemist can become a difficult target to effectively lockdown and kill, thanks to the health regeneration and movement speed bonuses granted by his ultimate.
* Alchemist is an ineffective target for Doom. Alchemist isn't totally reliant on his skills to be effective during a teamfight, due to the right-click nature of the hero.

* Doom does not disable Mana Shield. As such, Doom's damage is largely mitigated by her mana shield. Additionally, Medusa is not reliant on her abilities to be effective during a teamfight, making Medusa an unproductive hero to target.
* Medusa is an ideal Linken's Sphere carrier. Should one be purchased, and without any additional disables, Doom may find that few opportunities exist to effectively lockdown, disable, and kill Medusa.

* Despite the armor reduction from Meld, Templar Assassin's reliance on physical damage and medium attack speed is unlikely to harm Dragon Knight.
* Templar Assassin's Refraction charges also get quickly removed by the damage over time from Dragon Knight's ultimate.
Additional:
* The damage over time from Dragon Knight's Elder Dragon Form rapidly burns down Refraction, allowing him to attack her.
* Also, Breathe Fire reduces Templar Assassin's damage and Dragon Tail is a stun with a considerable duration, letting him and his team whittle her health down once her defenses wear off.
* Templar Assassin will struggle to kill Dragon Knight thanks to his high armor and health regen from Dragon Blood as she deals entirely physical damage.

* Multiple attackers thanks to summoned units or clones: Meepo, Witch Doctor, Lycan, Enigma, Shadow Shaman
* 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), Jakiro, 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.

* Heroes with a slow attack rate will find themselves struggling to take out Tombstone, like Doom.

* Templar Assassin's Refraction will easily be removed by Eye of the Storm, and Static Link reveals Templar Assassin hiding with Meld and drain the bonus damage from Refraction.

Additional:
* 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 can easily strike her during Meld.

* Heroes with the ability to heal allies, or those with good defensive abilities: Chen, Dazzle, Io, Oracle, Omniknight, Witch Doctor, Winter Wyvern, Abaddon, etc.

* 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), Jakiro, 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), Jakiro, Pugna

* 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.

* Heroes who often build Linken's Sphere: Weaver, Morphling, Medusa.

* Any hero who lanes very poorly will struggle with Primal Beast's potential snowball in the very early levels, like Keeper of the Light, Luna, Templar 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.

* 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.

* Multiple attackers thanks to summoned units or clones: Meepo, Witch Doctor, Lycan, Enigma, Shadow Shaman
* 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), Jakiro, Pugna

* Heroes with the ability to heal allies, or those with good defensive abilities: Chen, Dazzle, Io, Oracle, Omniknight, Witch Doctor, Winter Wyvern, Abaddon, etc.

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

* Heroes who can disable Mars but cannot do any damage to him, meaning he just tanks their abilities: Doom, Magnus.

* Heroes who often build Linken's Sphere: Weaver, Morphling, Medusa.

* Huskar's burn damage from Burning Spear is incredibly strong against Templar Assassin as it completely cancels out her Refraction from the burning over time which results in making her very vulnerable to ganks and harassments, and in turn forcing her out of the lane.

* 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.

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

* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.

* Drow Ranger can be difficult to get on top of, thanks to her Frost Arrows and Gust. With these two abilities, Drow Ranger is able to effectively 'kite' Doom and minimize his impact during team fights and laning stage.
* Much of Drow Ranger's effectiveness comes from her passive, which is not disabled by Doom.

* Venomancer's entire arsenal deals lingering damage over a long time and therefore burns through her Refraction very quickly. Not only that, his persistent slow from Poison Sting (and can be re-apply again and again with Plague Ward) allows his team to catch up to her even with the disruption from her Psionic Trap.
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.

* Feast deals damage and heals Lifestealer based on the target's maximum HP, which is greatly effective against naturally high HP heroes such as Doom.
* Rage allows Lifestealer to become spell immune to negate the magical damage of Infernal Blade and Scorched Earth.
* Doom has no effective means of escape from Open Wounds. This is particularly devastating in lane, where Doom may have to play a much more passive, conservative play style as a result.

* Wraith King has three passive abilities and only a single active ability, so Doom does not hinder him significantly.
* Doom expires upon death, so it is effectively removed after Reincarnation activates.
Additional:
* Even if he is Doomed, Wraith King can tear down Doom with physical attacks, and can still reincarnate as long as it is off-cooldown.

* Swashbuckle quickly burns 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.

* Due to the nature of the hero, Sniper is typically situated in the back of the fight, potentially making him a difficult target to initiate on and fight.
* Sniper is largely a right-click hero, and as such isn't as an effective of a Doom target as other heroes.
* Thanks to Shrapnel and Headshot, Sniper is able to effectively 'kite' Doom, preventing him from closing the distance between the two.