* Broodmother can kill Enigma's Eidolons with Spawn Spiderlings, and spawn her spiderlings in their place. But remember that Enigma can do the same to Broodmother's spiderlings with Demonic Conversion and Midnight Pulse.
* Without the protection from Black King Bar, Broodmother can cancel Enigma's Black Hole with Bloodthorn and make him more vulnerable to damage. Broodmother can also buy Abyssal Blade to cancel Enigma's Black Hole even through Black King Bar.
* Silken Bola causes Enigma's attacks to miss a lot and renders him more vulnerable to magical damage. And if Broodmother takes 400 AoE Silken Bola, then she will be able to use to cause Enigma's Eidolons to miss their attacks as well. In addition, Enigma does not like to buy items to provide him true strike such as Bloodthorn, Monkey King Bar, Witch Blade and it's upgrade Revenant's Brooch.
* If Broodmother is lucky enough to survive being trapped in Black Hole, she will be able to recover her lost health with Insatiable Hunger.
* Aghanim's Scepter gives Broodmother access to Spinner's Snare, which allows her to create invisible lines on her webs from Spin Web that will root Enigma, deal damage over time to Enigma and reveal Enigma if he unwittingly steps on them, disrupting his attempts to initiate with Black Hole, prevent him from using Blink Dagger, while also alerting Broodmother on his attempts to ambush her and her allies.
Additional:
* Broodmother can kill Enigma's Eidolons with Spawn Spiderlings, and spawn her spiderlings in their place. And Enigma can't use Demonic Summoning to instantly kill spiderlings at once.
* Without the protection from Black King Bar, Broodmother can cancel Enigma's Black Hole with Bloodthorn and make him more vulnerable to damage. Broodmother can also buy Abyssal Blade to cancel Enigma's Black Hole even through Black King Bar.
* Silken Bola causes Enigma's attacks to miss a lot and renders him more vulnerable to magical damage. And if Broodmother takes 400 AoE Silken Bola, then she will be able to use to cause Enigma's Eidolons to miss their attacks as well. In addition, Enigma does not like to buy items to provide him true strike such as Bloodthorn, Monkey King Bar, Witch Blade and it's upgrade Revenant's Brooch.
* If Broodmother is lucky enough to survive being trapped in Black Hole, she will be able to recover her lost health with Insatiable Hunger.
* Aghanim's Scepter gives Broodmother access to Spinner's Snare, which allows her to create invisible lines on her webs from Spin Web that will root Enigma, deal damage over time to Enigma and reveal Enigma if he unwittingly steps on them, disrupting his attempts to initiate with Black Hole, prevent him from using Blink Dagger, while also alerting Broodmother on his attempts to ambush her and her allies.

* Viper's lack of escape and durability means he can be ran over in a laning stage by Spawn Spiderlings.
* Broodmother can bring Viper down quickly with Insatiable Hunger activated.

* Enigma's abilities have a huge mana cost, meaning that Nether Ward will deal a lot of damage to Enigma.
* Pugna can heal allies trapped inside Black Hole thanks to Life Drain, Pugna can also damage multiple of Enigma's allies around him with Life Drain when he casts it on Aghanim's Shard upgraded Nether Ward during teamfight.
* Nether Blast can easily kill Eidolons, especially when Enigma is pushing.
* Even though Pugna cannot cancel Black Hole on his own, smart Pugna can buy Orchid Malevolence to stop Enigma from channeling Black Hole and make him more vulnerable to counter-attacks with Decrepify and Life Drain.
Additional:
* Enigma's abilities have a huge mana cost, meaning that Nether Ward will deal a lot of damage to Enigma.
* Pugna can heal allies trapped inside Black Hole thanks to Life Drain.
* Nether Blast can easily kill Eidolons, especially when Enigma is pushing.

* Pugna's Decrepify allows him to save allies from being ganked by Viper, since Viper mostly relies on direct attacks in order to deal damage.
* Nether Ward can discourage Viper from spamming his abilities.
* Viper's damage over time is not enough to kill Pugna as he will have more than enough time to save himself (or his allies) with Life Drain and Viper has no solutions to cancel it.
* Pugna has no passive abilities, which renders Nethertoxin nearly useless.

* Despite Clinkz's fragility, his harassment in the early game can be devastating; as he can kite Enigma and his Eidolons and claim their bounty with Burning Barrage and Tar Bomb.
* Clinkz often goes for a disabling item like Bloodthorn or Gleipnir, which allows him to cancel Enigma's Black Hole until Enigma gets Black King Bar. Gleipnir can also root Enigma, preventing him from using Blink Dagger to escape from Clinkz.
* Even with Black King Bar, Clinkz can still easily kill Enigma as all of his abilities ingore spell immunity, and Enigma is a very easy target for Burning Barrage, which means Clinkz can solo Enigma at any stage of the game unless Clinkz is caught in Black Hole.

* Clinkz does not have any passive abilities at all, making Nethertoxin nearly useless.
* Viper's Corrosive Skin provides no protection against Clinkz's physical damage output.

* Telekinesis has a longer range than the AoE of Black Hole for the purposes of cancelling it.
* All of Enigma's spells are useful to Spell Steal.
* Malefice is useful for interrupting channeling spells or long cast animations. Its stun duration is also amplified thanks to Spell Steal's debuff amplification.
* Demonic Conversion can be used to push or counter-push a lane.
* Midnight Pulse is useful to block an area or for team fights.
* Black Hole is very easy to steal, as it is a channeled ability. It's also one of the best ultimate abilities for team fights, and it can easily turn the fight around for the enemy team. It also does more damage and has a larger cast range thanks to Arcane Supremacy. A stolen Black Hole can also cancel Enigma's Black Hole.
Additional:
* Enigma's signature Black Hole can be devastating if being stolen and dropped on multiple heroes.
* Black Hole requires channeling. Since Enigma has no other ability to replace his last casted spell during channeling, Rubick can steal Black Hole relatively easily if he stays back.
* Rubick can interrupt Black Hole from Enigma, even with an activated Black King Bar, by casting the spell with Enigma in range with regards to the extra cast range granted by Arcane Supremacy.
* Black Hole can be interrupted by Telekinesis in the early game, giving enough time window to steal the spell.
* Bear in mind that an experienced Enigma will purchase Black King Bar and Linken's Sphere at the same time to prevent Rubick from stealing the spell, yet the extra Linken's Sphere will delay Enigma's power spike, so use it to Rubick's advantage.
* It is advised to build items around Black Hole as Rubick. Aghanim's Shard, Black King Bar , Aghanim's Scepter and even Refresher Orb are all legitimate item choices.
* Malefice is a decent source of damage and stun that helps with ganking. If stolen, it can be used to interrupt Black Hole as well.
* Demonic Conversion helpes with pushing and farming for Rubick.
* Fade Bolt effectively negates damage from Eidolons and helps with counter-pushing.
* Midnight Pulse is a solid skill for farming and teamfight damage, which is further amplified by Arcane Supremacy and talents.
* Unexpected enemy may take the effect of Midnight Pulse as that of Enigma's and soak up damage while unrealized.

* If Rubick can use Spell Steal to take Nethertoxin, he will be able to disable Corrosive Skin, reducing much of Viper's durability.
* He can also steal Viper Strike, which can be used to hinder a hero on your team (or multiple heroes, if Rubick has Aghanim's Scepter).

* Walrus PUNCH! can interrupt Black Hole and it can pierce spell immunity and neither Black King Bar nor Linken's Sphere can protect Enigma from Walrus PUNCH! as Walrus PUNCH! is an auto-cast ability.
* In pretty much any phase of the game, Tusk's abilities can easily cancel Black Hole and disrupt Enigma's positioning.

* Viper Strike can be countered through Snowball, wasting Viper's mana through his ultimate. It's Viper Strike's break is also useless because he has no passive abilties at all. And to make things worse, Viper Strike cannot disable Walrus PUNCH! because it's an auto-cast ability
* As Tusk is a natural Silver Edge wielder, he can use it to disable Viper's magic resistance from Corrosive Skin, and make him vulnreable to his other allies.

* An isolated Enigma in the early game can be easily killed by Storm Spirit thanks his higher mobility and dueling potential. However, Storm Spirit can be killed when caught by Enigma's full combo, especially if Enigma has Black King Bar.
* Storm can kill all of Enigma's Eidolons relatively quickly without much risk, slowing down Enigma's farming speed, preventing him from split pushing, and giving Storm its considerable bounty, especially if Enigma chooses the Level 25 Talent that gives him more Eidelons.
* Storm can zip through Black Hole stunning Enigma while he's channelling until Enigma buys Black King Bar.

* Ball Lightning allows Storm Spirit to escape through Viper Strike, wasting Viper's mana.
* It's also very easy to wait out the duration of Nethertoxin's break.

* Without Black King Bar, Luna will be able to cancel Enigma's Black Hole from safe distance with her Lucent Beam or with 0.25s Eclipse Lucent Ministun talent for Eclipse and counter-initiate with Eclipse. This can get even worse for Enigma once Luna gets Aghanim's Scepter and combines it with 0.25s Eclipse Lucent Ministun talent that will allow Luna to use Eclipse from safe distance.
* If Luna chooses to use Eclipse in anticipation right after Enigma jumps in with Blink Dagger, she will be able to kill Enigma before he even gets a chance to use Black Hole. Aghanim's Scepter upgraded Eclipse can be used to counter-initiate against Enigma from safe distance if he has no Black King Bar available to use.
* Luna commonly buys Satanic, which can help her recover from Enigma's Black Hole in case she survives it.
* Moon Glaives combined with Lunar Blessing can make a short work of Enigma's Eidolons before Luna uses Eclipse. Aghanim's Shard upgraded Moon Glaives can be used to reduce damage Luna will take from Enigma's Eidolons and Black Hole if used in anticipation while also clearing waves of Enigma's Eidolons and damaging Enigma if he is too close to Luna.
* Bear in mind, however, that once Enigma gets Black King Bar, Luna will be out of solutions to cancel Black Hole, and going for Abyssal Blade on Luna can be risky due to Abyssal Blade's very short cast range.
Additional:
* Without Black King Bar, Luna will be able to cancel Enigma's Black Hole from safe distance with her Lucent Beam or with 0.25s Eclipse Lucent Ministun talent and counter-initiate with Eclipse. This can get even worse for Enigma once Luna gets Aghanim's Scepter and combines it with 0.25s Eclipse Lucent Ministun talent that will allow Luna to use Eclipse from safe distance.
* If Luna chooses to use Eclipse in anticipation right after Enigma jumps in with Blink Dagger, she will be able to kill Enigma before he even gets a chance to use Black Hole.
* Luna commonly buys Satanic, which can help her recover from Enigma's Black Hole in case she survives it.
* Moon Glaives combined with Lunar Blessing can make a short work of Enigma's Eidolons before Luna uses Eclipse.
* Bear in mind, however, that once Enigma gets Black King Bar, Luna will be out of solutions to cancel Black Hole, and going for Abyssal Blade on Luna can be risky due to Abyssal Blade's very short cast range.

* Even though Luna has a hard time laning against Viper due to Nethertoxin being able to disable Moon Glaives and Lunar Blessing, Luna can take out Viper once she builds either Black King Bar or Silver Edge which will allow her to attack Viper freely.
* Eclipse can often finish off Viper from early-to-mid stages of the game before he can retaliate as Corrosive Skin gives little magic resistance to him early on.
* Manta Style is an item that Luna commonly buys in most of the games, which lets her disjoint Viper Strike. Additionally, illusions from Manta Style can make Viper waste time attacking them.
Additional:
* Even though Luna has a hard time laning against Viper due to Nethertoxin being able to disable Moon Glaives and Lunar Blessing, Luna can take out Viper once she builds either Black King Bar or Silver Edge which will allow her to attack Viper freely.
* Eclipse can often finish off Viper from early-to-mid stages of the game before he can retaliate as Corrosive Skin gives little magic resistance to him early on.
* Manta Style is an item that Luna commonly buys in most of the games, which lets her disjoint Viper Strike. Additionally, illusions from Manta Style can make Viper waste time attacking them.

* Heroes that depend on disrupting fights with ability combos or big ultimate abilities are vulnerable to the long stun of Fiend's Grip: Disruptor, Death Prophet, Enigma, Faceless Void, Invoker, Lich, Magnus, Mars, Medusa, Outworld Destroyer, Phoenix, Puck, Queen of Pain, Shadow Fiend, Treant Protector, Underlord, Winter Wyvern, Witch Doctor, Zeus.

* Enfeeble weakens Viper's attack damage, any healing he receives and his cast range, which makes him unable to harass enemy heroes with Nethertoxin, Poison Attack and Viper Strike.
* Brain Sap allows Bane to heavily harass Viper, damaging him while healing Bane, which allows Bane to fight back against Viper's damage over time output, even through debuff immunity from Black King Bar.
* Viper's Corrosive Skin is useless against Bane as all of his damaging abilities deal Pure damage.
* Viper has no solutions to cancel Fiend's Grip and in addition, he hates buying disabling items like Eul's Scepter of Divinity.
Additional:
* Enfeeble weakens Viper's attack damage, any healing he receives and his cast range, which makes him unable to harass enemy heroes with Nethertoxin, Poison Attack and Viper Strike.
* Viper's Corrosive Skin is useless against Bane as all of his damaging abilities deal Pure damage.
* Viper has no solutions to cancel Fiend's Grip and in addition, he hates buying disabling items like Eul's Scepter of Divinity.

* Chaotic Offering's spell immunity piercing stun can stop Black Hole's channeling. Due to this ability's large area of effect, it can be cast at a safe distance from the Black Hole. It also goes through Black King Bar and ignores Linken's Sphere.
* Fatal Bonds and Aghanim's Shard upgraded Shadow Word can be used to make Enigma's Eidolons easier to kill, potentially feeding the enemy team. Also,their constant damage will put Blink Dagger on cooldown, potentially forcing Enigma to prematurely activate Black King Bar.
Additional:
* Chaotic Offering pierces spell immunity and is an area of effect ability, therefore it doesn't matter if Enigma buys Black King Bar or Linken's Sphere, Warlock will always be able to cancel the channeling of Black Hole.
* Enemies often get clumped up around Black Hole to hit your allies, giving you a perfect opportunity to cast Fatal Bonds, Chaotic Offering, and Upheaval on multiple enemies.

* Viper cannot interrupt heroes with powerful channeling abilities: Bane, Enigma, Shadow Shaman, Warlock

* Enigma lacks burst damage, and that makes him vulnerable to heroes who can recover themselves and turn the fight around to their advantage after Enigma finishes his initiation: Faceless Void, Terrorblade, Ursa, Weaver, Broodmother, Slark, Abaddon, Wraith King, Lifestealer.

* Shukuchi ignores slows and allows Weaver to escape Viper's onslaught.
* Time Lapse dispels Poison Attack and Corrosive Skin and undoes poison damage.
* Weaver's high burst damage allows him to kill Viper before being killed.

* Like Abbadon's Borrowed Time, Reincarnation can bring Wraith King back to life, giving him a second chance to counter initiate or escape after a Black Hole combo. And since Enigma is not used to buy Diffusal Blade, this can be a very big problem for him.
* Without protection from Black King Bar, Wraith King can also cancel Black Hole with Wraithfire Blast that can also deal damage over time, putting Blink Dagger on cooldown.
* Vampiric Spirit can summon many skeleton warriors that can be used to deal with Enigma's Eidolons.

* Viper's Nethertoxin cannot disable Reincarnation, which could put him in disadvantage against Wraith King if his whole team is with him.
* In addition, Viper doesn't like buying Diffusal Blade, which is the only item that can help him against Wraith King.
* Wraith King's high burst damage allows him to kill Viper before being killed.

* Illuminate can wipe the pushing Eidolons in a lane with ease, diminishing Enigma's laning presence by a lot.
* Solar Bind will severely slow down Enigma and make him more vulnerable to magical damage more he moves for it's duration.
* However, Keeper of the Light does not have any way to cancel Black Hole outside from Will-O-Wisp provided by Aghanim's Scepter.

* The Keeper of the Light easily farms on the line against the Viper, due to the fact that it has a long-range Illuminate, and the Viper, in turn, cannot use its advantage of dominance on the center line, due to the fact that it does not reach the Keeper of the Light
Additional:
* The Keeper of the Light easily farms on the line against the Viper, due to the fact that it has a long-range Illuminate, and the Viper, in turn, cannot use its advantage of dominance on the center line, due to the fact that it does not reach the Keeper of the Light

* Heroes who can clear the waves of Enigma's Eidolons: Lina, Luna, Dawnbreaker, Jakiro, Shadow Shaman, Death Prophet, Keeper of the Light, Invoker, Leshrac, Puck.

* Viper cannot interrupt heroes with powerful channeling abilities: Bane, Enigma, Shadow Shaman, Warlock

* Heroes that rely on summons will suffer against Ion Shell, which kills them very quickly: Beastmaster, Broodmother, Enigma, Nature's Prophet, Visage, Warlock, Wraith King.

* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, Pugna, Nature's Prophet, Dark Seer, Lycan, Tusk

* Enigma is fragile, and lacks escapes, being dependent on Blink Dagger for mobility. Ganking Heroes or Heroes with burst damage will likely kill him before he can do anything. Such Heroes include: Lina, Lion, Luna, Puck, Slark, Nyx Assassin, etc.

* Heroes that can drain mana negatively affect Viper's ability to use Poison Attack, Nethertoxin and Viper Strike: Lion, Anti-Mage

* Long ranged disables, especially those that pierce spell immunity, cancel Black Hole: Beastmaster's Primal Roar, Bane's Fiend's Grip, Faceless Void's Chronosphere, Magnus's Reverse Polarity, Axe's Berserker's Call, Pudge'sMeat Hook.

* Illusion or summon-based heroes can be a problem to Viper due to his lack of AoE damage: Naga Siren, Phantom Lancer, Beastmaster

* Winter's Curse, when directly targeted on Enigma, goes through Black King Bar, stopping Enigma's Black Hole channeling. It also turns his team against him, potentially killing him. Even if Enigma gets Linken's Sphere on top of Black King Bar, Splinter Blast can be used to pop Linken's Sphere, and Winter's Curse will stop Black Hole channeling.
* Splinter Blast can be targeted on an eidolon, killing off other eidolons and damaging nearby heroes as well.

* Viper is an agility hero, and his item build mostly includes agility items, so Natural Order can be devastating, removing all armor and greatly decreasing the effectiveness of Corrosive Skin, weakening Viper's magic resistance. Additionally, Echo Stomp and Earth Splitter deal both magical and physical damage, and can help bringing Viper down fast.
* Aghanim's Scepter may be necessary to take Viper down due to Nethertoxin's break.

* Viper is kind of a mixed package. Tinker is very good against him. but stands a better chance against him than most heroes.
* Viper has a high innate magic resistance, but relies on his primary attacks to really deal damage. making Laser an effective way to save allies from him, and deal damage. Keep in mind that his Corrosive Skin will prevent Tinker from blinking.
* Viper's Viper Strike and Poison Attack will also have a hard time damaging allies through Tinker's constant casting of Defense Matrix.
* Viper has no solutions to cancel Rearm nor any of Tinker's escape attempts with Boots of Travel
* However, if Viper gets a jump on Tinker first. Tinker will unlikely survive versus Viper.

* Black Hole requires channelling, making it easy to be interrupted with Hookshot.
* Enigma lacks mobility without a Blink Dagger and also is squishy, making him fall easily when ganked by Clockwerk.
Additional:
* Hookshot's stun pierces through spell immunity and Enigma's channeling can be easily cancelled from a safe distance, assuming none of his allies are in the way, and the Black Hole is not centered directly on Enigma.

* Viper has no disable, which means he has no way of preventing Morphling from escaping from any of his abilities or keep him inside Nethertoxin.
* Viper is almost exclusively damage over time, which is weak against Morphling due to Attribute Shift (Strength Gain). Additionally, Morphling has no passive abilities, reducing Nethertoxin's effectiveness against him even further.
* Morphling can turn into Viper himself, allowing him to use any of Viper's abilities against him (excluding Viper Strike). This is particularly bad due to the fact that Viper is already a very slow hero, making Poison Attack and Corrosive Skin's slows especially difficult to deal with.

* Astral Imprisonment can save allies from a Black Hole combo. When upgraded with Aghanim's Scepter and Aghanim's Shard, it becomes exceedingly difficult for Enigma to land a good Black Hole against Outworld Destroyer and his team.
* Astral Imprisonment can also cancel Black Hole while Enigma does not have Black King Bar.
* Arcane Orb and Sanity's Eclipse can often make a short work out of Enigma and his Eidolons.

* Blood Rite can potentially force him to activate Black King Bar prematurely, before pulling off a Black Hole combo.
* Bloodseeker can find an Enigma out of position and Rupture him, making it difficult to initiate properly in a team fight, as it pierces through Black King Bar.

* Black Hole while definitely a threat to Drow Ranger, is very hard to land as she likes to keep her distance from allies and enemies alike. And if not caught in it, will kill Enigma very quickly due to his low health.
* Malefice can be removed with a Manta Style.
* Drow Ranger being a fairly low health, high armored agility carry doesn't take much damage from Midnight Pulse as others would.
* Demonic Conversion units die very quickly to Marksmanship or even just regular attacks not far into the game within 2 or 3 hits.

* Medusa's Split Shot can make quick work of Enigma's Eidolons and take advantage of their considerable bounty.
* Medusa can also kill Eidolons with her Mystic Snake that can also greatly damage Enigma and drain some of his mana.
* If Medusa activates Stone Gaze at the start of a fight, it can make initiating and landing an effective Black Hole exceedingly difficult, because Stone Gaze can cancel Enigma's Black Hole even through spell immunity, which can discourage Enigma from even trying to initiate with Black Hole.
Additional:
* Medusa's Split Shot can make quick work of Enigma's Eidolons and take advantage of their considerable bounty.
* If Medusa activates Stone Gaze at the start of a fight, it can make initiating — and landing an effective Black Hole exceedingly difficult. Stone Gaze can cancel Enigma's Black Hole even through spell immunity, which can discourage Enigma from initiating with Black Hole.

* Black Hole is a channeling ability and Earth Spirit has at least two possibilities which can interrupt these kind of spells. Enigma is exposed and cannot move while using Black Hole, thus making it easy for Earth Spirit to stop the feared ability with the huge range of Rolling Boulder and forcing Enigma to quickly rush a Black King Bar to prevent this.
* Enigma is level dependant, squishy and relativly defenseless in the early game and therefore vulnerable to aggressive roam maneuvers in this stage of the game. Earth Spirit excels at ganking, shutting down a jungling or otherwise solo farming Enigma.

* Most of the of Jakiro's damage-over-time abilities put Blink Dagger on cooldown, potentially forcing Enigma to prematurely activate Black King Bar.
* Jakiro's Dual Breath, Liquid Fire, Macropyre and Liquid Frost from Aghanim's Shard can take out Enigma's Eidolons, reduce Enigma's attack speed and put Enigma's Blink Dagger on cooldown.
* Jakiro can easily cancel Black Hole with Ice Path as Enigma is a very easy target while channeling it.
* Aghanim's Scepter upgraded Macropyre can deal pure damage-over-time and pierce spell immunity, which can discourage Enigma from even trying to initiate with Black Hole.
Additional:
* Most of the of Jakiro's damage-over-time abilities put Enigma's Blink Dagger on cooldown, potentially forcing him to prematurely activate Black King Bar.
* Jakiro's Dual Breath, Liquid Fire, Macropyre and Liquid Frost from Aghanim's Shard can take out Enigma's Eidolons, reduce Enigma's attack speed and put Enigma's Blink Dagger on cooldown.
* Jakiro can easily cancel Black Hole with Ice Path as Enigma is a very easy target while channeling it.
* Aghanim's Scepter upgraded Macropyre can deal pure damage-over-time and pierce spell immunity, which can discourage Enigma from even trying to initiate with Black Hole.

* Voodoo Restoration heals to counter damage over time of Viper abilities.
* Viper has no way to cancel Death Ward, even through Rod of Atos.

* Even with Black King Bar, Pudge's Meat Hook and Dismember can still disable Engima while he is channeling Black Hole as Enigma is a very easy target while channeling Black Hole.
* Pudge's Aghanim's Shard upgraded Dismember and Meat Hook are great ways to save allies from Black Hole.
* Enigma is prone to ganks in the jungle or in the off-lane without proper vision. Pudge can take advantage of Enigma's lack of mobility, and gank him often.

* Enigma lacks burst damage, and that makes him vulnerable to heroes who can recover themselves and turn the fight around to their advantage after Enigma finishes his initiation: Faceless Void, Terrorblade, Ursa, Weaver, Broodmother, Slark, Abaddon, Wraith King, Lifestealer.

* Almost all of Viper's damage revolves exclusively around single-target damage-over-time effects. Furthermore, without any hard disables, Terrorblade can almost always get a Sunder off.
* Viper has low mobility and Corrosive Skin doesn't protect against physical damage, which means that Terrorblade under Metamorphosis can quickly kill Viper.
Additional:
* Viper's damage over time and lack of disables makes him easy to Sunder.
* Viper's physical damage is mitigated by Terrorblade's high armor.
* Terrorblade under Metamorphosis can quickly kill Viper with heavy physical damage.

* Although Viper Strike cannot be dispelled by Doppelganger, Viper's lack of mobility and AoE damage makes him an easy target for Phantom Lancer.
* Viper's various slows do not work against Phantom Rush.
* Although Phantom Lancer should be wary due to Nethertoxin applying Break.
Additional:
* Phantom Lancer can overwhelm Viper with spawned illusions from Spirit Lance and Doppelganger. In addition, Diffusal Blade, a core item on Phantom Lancer, burns Viper's limited mana pool, reducing his potential poison damage.
* Viper's various slows do not work against Phantom Rush. Additionally, it is almost impossible to keep Lancer inside Nethertoxin's radius in order to disable the passive.

* Enigma lacks burst damage, and that makes him vulnerable to heroes who can recover themselves and turn the fight around to their advantage after Enigma finishes his initiation: Faceless Void, Terrorblade, Ursa, Weaver, Broodmother, Slark, Abaddon, Wraith King, Lifestealer.

* Rage ignores all of Viper's magical damage, although Viper Strike can pierce spell immunity and slows him down.
* Feast and Open Wounds from Aghanim's Shard can be combined to heal through Viper's physical damage.
* Aghanim's Scepter upgraded Infest can be used to disarm Viper, preventing him from using Poison Attack on Lifestealer's allies.

* Heroes who can clear the waves of Enigma's Eidolons: Lina, Luna, Dawnbreaker, Jakiro, Shadow Shaman, Death Prophet, Keeper of the Light, Invoker, Leshrac, Puck.

* Ice Wall and Ghost Walk can be used to kite and escape from Viper.
* Chaos Meteor and Sun Strike deal heavy damage and can quickly bring Viper down.
* Cold Snap, Tornado, and Deafening Blast are powerful disables that reduce Viper's effectiveness.
* E.M.P. burns Viper's limited mana pool, reducing his potential poison damage.
* Forge Spirits can melt Viper's armor and reduce his durability.

* Heroes who rely on magical damage resistance may have a hard time laning against Dazzle as all of Dazzle's abilities deal physical damage instead of magical: Anti-Mage, Huskar, Viper.

* Heroes who can clear the waves of Enigma's Eidolons: Lina, Luna, Dawnbreaker, Jakiro, Shadow Shaman, Death Prophet, Keeper of the Light, Invoker, Leshrac, Puck.

* Enigma's Midnight Pulse damage can be substantially mitigated by Anti-Mage's high magic resistance thanks to Counterspell.
* In the early game, Anti-Mage's Mana Void can cancel a Black Hole until Enigma gets Black King Bar.
* Should Anti-Mage survive a Black Hole combo, Enigma will have exhausted most of his skills and items, preventing him from defending himself against any counter initiation or a follow-up from a blink escape.
* Anti-Mage's Blink will make him a very hard target to use Black Hole on, having to solo ult him later on in the game or leave him out of the Black Hole.

* Heroes that can drain mana negatively affect Viper's ability to use Poison Attack, Nethertoxin and Viper Strike: Lion, Anti-Mage

* Heroes that cannot move in fights such as a Dueling Legion Commander or anyone channeling a spell like Bane, Pudge, or Enigma are easy Sacred Arrow targets.

* Ranged heroes will have a hard time hitting enemies inside Magnetic Field: Silencer, Viper.

* Heroes who can clear the waves of Enigma's Eidolons: Lina, Luna, Dawnbreaker, Jakiro, Shadow Shaman, Death Prophet, Keeper of the Light, Invoker, Leshrac, Puck.

* Heroes with powerful channeling abilities are easily interrupted by Phantom's Embrace: Bane, Pudge, Witch Doctor, Crystal Maiden, Enigma.

* Enigma lacks burst damage, and that makes him vulnerable to heroes who can recover themselves and turn the fight around to their advantage after Enigma finishes his initiation: Faceless Void, Terrorblade, Ursa, Weaver, Broodmother, Slark, Abaddon, Wraith King, Lifestealer.

* Heroes who produce many summons will have a hard time against Storm's Dispel Magic during teamfight: Broodmother, Enigma, Nature's Prophet.

* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, Pugna, Nature's Prophet, Dark Seer, Lycan, Tusk

* 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.

* Viper's frailty and low mobility make him an enticing Duel target and Corrosive Skin doesn't protect him against Legion Commander physical attacks.
* Press the Attack can dispel Poison Attack.
* Viper slows can easily negate by Overwhelming Odds movement speed.

* Windrun evades Poison Attack and counteracts the slow.
* Viper's low mobility makes him an easy Shackleshot target.
* Focus Fire grants Windranger significant physical damage output to quickly wear Viper down.
* Powershot is a strong harassment and zoning tool against Viper in lane.

* Naga Siren can easily disjoint, and dispel Corrosive Skin with Mirror Image.
* Since Viper is mostly a single-target hero, he will not have almost any chance against Naga Siren because she is an illusion based hero.
* Viper has no burst damage, so Naga Siren will have plenty of time to use Aghanim's Shard upgraded Song of the Siren heal her allies before Viper can finish them off.

* Heroes who can clear the waves of Enigma's Eidolons: Lina, Luna, Dawnbreaker, Jakiro, Shadow Shaman, Death Prophet, Keeper of the Light, Invoker, Leshrac, Puck.

* Long ranged disables, especially those that pierce spell immunity, cancel Black Hole: Beastmaster's Primal Roar, Bane's Fiend's Grip, Faceless Void's Chronosphere, Magnus's Reverse Polarity, Axe's Berserker's Call, Pudge'sMeat Hook.

* Enigma is fragile, and lacks escapes, being dependent on Blink Dagger for mobility. Ganking Heroes or Heroes with burst damage will likely kill him before he can do anything. Such Heroes include: Lina, Lion, Luna, Puck, Slark, Nyx Assassin, etc.

Additional:
* Enigma's uncontrollable damage from Malefice and Midnight Pulse make him easy to stun with Spiked Carapace.
* Black Hole can be easily interrupted by Impale or Spiked Carapace.

* Long ranged disables, especially those that pierce spell immunity, cancel Black Hole: Beastmaster's Primal Roar, Bane's Fiend's Grip, Faceless Void's Chronosphere, Magnus's Reverse Polarity, Axe's Berserker's Call, Pudge'sMeat Hook.

* 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.

* Heroes who can clear the waves of Enigma's Eidolons: Lina, Luna, Dawnbreaker, Jakiro, Shadow Shaman, Death Prophet, Keeper of the Light, Invoker, Leshrac, Puck.

* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, Pugna, Nature's Prophet, Dark Seer, Lycan, Tusk

* Enigma lacks burst damage, and that makes him vulnerable to heroes who can recover themselves and turn the fight around to their advantage after Enigma finishes his initiation: Faceless Void, Terrorblade, Ursa, Weaver, Broodmother, Slark, Abaddon, Wraith King, Lifestealer.

* Heroes who can clear the waves of Enigma's Eidolons: Lina, Luna, Dawnbreaker, Jakiro, Shadow Shaman, Death Prophet, Keeper of the Light, Invoker, Leshrac, Puck.

* Stone Form can easily interrupt heroes with long channeling spells, like Crystal Maiden, Bane, Witch Doctor, or Enigma.

* Doom pierces spell immunity and can prevent Enigma from casting any spells or using items until the duration of the spell depletes, as well as cancelling a Black Hole.
* While Doom can be blocked by a Linken's Sphere, which is a common item on Enigma, Aghanim's Scepter upgraded Doom allows Doom to cast Doom on himself to affect enemies near him, and if Doom can combine this with Blink Dagger, he will be able to jump on Enigma while he is channeling Black Hole. Aghanim's Scepter upgraded Doom can also cancel Black Hole if any of Enigma's allies affected by Doom gets too close to him for it's duration, ignoring both, Black King Bar and Linken's Sphere.

* Heroes who have summons, which can be quickly cleared by his powerful area of effect skill: Nature's Prophet, Enigma, Lycan

* Riki can potentially catch an Enigma out of position and prevent him from properly blinking and initiating, thanks to Cloak and Dagger.
* Before Enigma gets his Black King Bar, Smoke Screen can be used to cancel Black Hole. After Enigma gets Black King Bar, Riki can also cancel Black Hole with Abyssal Blade, which is a common item built on him.
* Tricks of the Trade renders Riki hidden and invulnerable, which in combination with Abyssal Blade allows Riki to cancel Black Hole with little to no worries of getting caught in it.
* Enigma's fragility during all stages of the game makes him extremely prone to Riki's ganking.

* Take Aim extends Sniper's attack range, allowing him to position himself safely behind his team, making it difficult to catch him in Enigma's relatively small area-of-effect for Black Hole. When left unattended, he can quickly kill a channeling Enigma (often from the high ground) to rout an otherwise strong initiation.
* In the early game, Sniper can cancel Enigma's Black Hole with Assassinate's ministun. Due to the absolutely ginormous 3000 cast range on Assassinate, Sniper does not need to be too close to Enigma to cancel his Black Hole. Aghanim's Scepter upgraded Assassinate can also stun Enigma for a longer duration.
* Both Shrapnel and Assassinate put Enigma's Blink Dagger on cooldown, potentially forcing him to prematurely activate Black King Bar.
Additional:
* Sniper has a very long range, so it is rare that Enigma can catch him in a Black Hole.
* Assassinate can easily cancel Black Hole if he is not caught, especially with Aghanim's Scepter.
* Enigma's Eidolons from Demonic Conversion are useless to push against a Sniper as he will easily kill them, especially with Mjollnir, a common item on Sniper.

* Zeus can break Blink Dagger with his long range abilities and global range ultimate, Thundergod's Wrath.
* Lightning Bolt has a long range and a mini-stun, providing a way for him to cancel Black Hole from safe distances, assuming Enigma doesn't have his Black King Bar.
* Zeus's Aghanim's Scepter grants him Nimbus ability that has a global range and mini-stun, making it an even more effective way to cancel Black Hole before Enigma initiates with Black King Bar.
* Zeus is typically able to position himself at a safe distance from the fight, making him a difficult target to capture in a Black Hole.

* Enigma lacks burst damage, and that makes him vulnerable to heroes who can recover themselves and turn the fight around to their advantage after Enigma finishes his initiation: Faceless Void, Terrorblade, Ursa, Weaver, Broodmother, Slark, Abaddon, Wraith King, Lifestealer.

* Haunt can ruin Enigma's initiation with Blink Dagger, no matter where he is on the map.
* Spectre often buys Radiance, which allows her to deal damage over time to Enigma and put Blink Dagger on cooldown.
* Dispersion reflects the damage of Midnight Pulse and Black Hole inflicted back to Enigma. This can get even worse for Enigma if Spectre buys Blade Mail.
* All of Spectre's abilities ignore spell immunity, which means that even with Black King Bar, Enigma has absolutely little to no chance against Spectre at any stage of the game.

* Bristleback's constant harass from Quill Spray will greatly hurt Enigma's laning and kill his Eidolons.
* However, Bristleback has no way of canceling Black Hole at all. And Bristleback is not a hero that goes for disabling items to counter that problem.

* Borrowed Time can give Abaddon a second chance after a Black Hole combo.
* Aphotic Shield can be used to save allies or Abaddon himself from Malefice.
* Abaddon can easily heal himself as well as his allies during a team fight, especially with Aghanim's Scepter upgraded Borrowed Time.

* Fissure does a great job at interrupting Black Hole immediately, especially with Blink Dagger and Aether Lens.
* Echo Slam's damage potential increases due to the eidolons created by Demonic Conversion.

* Tidehunter's Anchor Smash will cripple all of Enigma's Eidolons, and at a higher level, Tidehunter will be capable to instantly kill the whole group of them for a boost of gold.
* Kraken Shell negates Eidolons's damage and Enigma's auto attacks, making laning against Tidehunter nearly impossible for Enigma.
* Ravage has an insane radius, and considering that Enigma is prone to waiting around for a Blink Dagger and Black King Bar combo, Ravage's stun may catch Enigma off guard and put Blink Dagger on cooldown, limiting him a crucial teamfight time.

* Vengeful Spirit can interrupt Black Hole's channeling through Black King Bar by using Nether Swap from a safe distance.
* Vengeful Spirit's Level 25 Talent can make her Magic Missile pierce spell immunity, giving her another option to use in conjunction with Nether Swap to cancel Enigma's Black Hole channeling even through both, Black King Bar and Linken's Sphere.

* Inner Fire can damage and disarm Enigma's eidolons, which can then be cleared out with Burning Spears.
* Huskar's Burning Spears can deal serious damage over time to Enigma during laning and teamfights, and it can also disable Blink Dagger for a long time.
* Berserker's Blood that provides Huskar with magic resistance and bonus health regeneration makes it difficult for Enigma to take down Huskar. Huskar is also a common Satanic wielder, which can help him recover from Enigma's Black Hole in case he survives it. Enigma's only source of dealing Pure Damage that can bypass Berserker's Blood. This forces Enigma to buy Silver Edge, the only item that can help him against Huskar's Berserker's Blood.
* However, Huskar does not have any way to cancel Black Hole outside from Aghanim's Scepter upgraded Life Break that can force Enigma to attack Huskar if used on him.