Viper
* 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.
Enchantress
* Enchantress's lack of area-of-effect abilities allows Broodmother to swarm her with Spiderlings.
* Spawn Spiderlings can kill enchanted creeps and create Spiderlings in their place.
* However, bear in mind that 
Untouchable makes it harder for Broodmother to actually hit Enchantress, even if Broodmother is spell immune. And Broodmother's only way to counter this is either by buying 
Silver Edge, buying items that deal high magical damage like 
Dagon, or by buying items that give high attack speed like 
Moon Shard.
Additional:
* Enchantress can be easily overwhelmed with Broodmother's spiderlings from Spawn Spiderlings and Enchantress can only control one of them with 
Enchant and she has no good waveclear (Spawn Spiderlings can also kill creeps controlled with Enchant).
* However, Untouchable's attack speed reduction can make it difficult for Broodmother to kill Enchantress even with any form of spell immunity.
Viper
* 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.
Enchantress
* Amazingly, Enchantress has even lower health than Pugna. Though she does pack quite a punch through 
Impetus, she can't use it if she is under Decrepify.
* Pugna's Magical DPS is way greater than the heal from 
Nature's Attendants, which will also harm her quite a bit if she's next to Nether Ward.
Viper
* Ranged heroes will have a hard time hitting enemies inside Magnetic Field: 
Silencer, 
Viper.
Enchantress
* Magnetic Field makes Impetus miss; if Enchantress decides to enter the field, she is giving up bonus damage since Impetus deals greater damage at higher distance away from targets.
Viper
* 
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.
Enchantress
* Heroes with nukes: 
Bane, 
Lich, 
Lion, 
Skywrath Mage
Viper
* Viper cannot interrupt heroes with powerful channeling abilities: Bane, 
Enigma, 
Shadow Shaman, 
Warlock
Enchantress
* Enchant can not control golem 
Chaotic Offering from Warlock.
Viper
* 
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.
Enchantress
* Heroes with haste can negate Enchant's slow: 
Weaver, 
Dark Seer, 
Lycan, 
Centaur Warrunner.
Viper
* 
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.
Enchantress
* Windrun's speed allows easy pursuit or escape, while the evasion greatly reduces the threat of Enchantress's Impetus, especially when retreating.
* Shackleshot is a powerful disable if Enchantress gets too close to one of her own minions.
* Focus Fire can negate Untouchable.
Viper
* Since Windranger is bad against magical damage, heroes with continuous magical damage or magical nukes can blast her: 
Zeus, 
Tinker, 
Leshrac, Viper, Skywrath Mage, Lion, 
Lina, 
Venomancer.
Viper
* 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.
Enchantress
* Enchantress has pitiful HP, even more pitiful than Luna, so 
Lucent Beam and Eclipse will often harass and/or kill her through her Untouchable.
* With Moon Glaives, Luna can clear Enchantress's creep wave efficiently.
Additional:
* Though Enchantress's Untouchable can greatly reduce Luna's attack speed, and can go through any form of Spell Immunity, she has a pitiful HP so Lucent Beam and Eclipse can kill her very quickly.
* Moon Glaives allows Luna to clear Enchantress's creeps very efficiently.
Enchantress
* Heroes that create illusions: 
Spectre, 
Shadow Demon, 
Phantom Lancer, 
Naga Siren, 
Chaos Knight, 
Terrorblade) or bring other units into the fight (such as 
Nature's Prophet, 
Lone Druid, 
Chen, 
Enchantress, 
Meepo and 
Arc Warden) can cause Eclipse to strike the illusions/summons unintentionally. However, in many cases Moon Glaives can resolve this issue and eliminate them before activating Eclipse, but that will require lots of farming for right-click items.
Viper
* Viper cannot interrupt heroes with powerful channeling abilities: Bane, Enigma, Shadow Shaman, Warlock
Enchantress
* Heroes with break can disable Untouchable for a while: 
Doom and Shadow Demon (via 
Aghanim's Scepter), Viper, Shadow Shaman with Hex Breaks talent.
Viper
* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: 
Clinkz, 
Pugna, Nature's Prophet, Dark Seer, Lycan, 
Tusk
Enchantress
* Heroes with haste can negate Enchant's slow: Weaver, Dark Seer, Lycan, Centaur Warrunner.
Viper
* Heroes that can drain mana negatively affect Viper's ability to use Poison Attack, Nethertoxin and Viper Strike: Lion, 
Anti-Mage
Enchantress
* Heroes with nukes: Bane, Lich, Lion, Skywrath Mage
Additional:
* Enchantress is very fragile without any form of magic resistance, allowing Lion to easily burst her down.
* Nature's Attendants is a slow heal, making not as much effective against Lion's burst as it could be.
* Her raw movement speed is a fair escape/mobility mechanism, which may allow her to avoid a blindly cast 
Earth Spike, but does nothing against the rest of Lion's abilities, since they are single target and can't miss.
* Since Lion's damage comes mostly from his skills, Untouchable does nothing to mitigate it.
Enchantress
* Enchantress often has a small army of neutral creeps, allowing Medusa to hit her with a later bounce of her Mystic Snake.
Viper
* 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.
Enchantress
* Untouchable doesn't work against Unleash, as Marci gains 1000+ attack speed for the fury combo.
* Enchantress' low health makes her a fragile target for Marci's damage blasts.
* Marci can use Rebound on one of her enchanted creeps to easily reach the Enchantress and negate the bonus damage dealt by her Impetus. It helps that most of her best creeps have a low attack range, creating a makeshift bridge towards their master.
Enchantress
* 
Blade Fury dispels the slow from Enchant, and can burst Enchantress down during the laning stage.
* 
Omnislash and 
Swiftslash's physical damage burst ignore untouchable.
* Silver Edge is a common item for Juggernaut for dealing with Untouchable.
Additional:
* Blade Fury dispels the slow from Enchant, spell immunity and used to burst her down during the early laning stage.
* Omnislash and Swiftslash's physical damage burst ignore Untouchable.
* Silver Edge is an ideal item for Juggernaut to deal with Untouchable, making her vulnerable to melee attacks.
Viper
* Voodoo Restoration heals to counter damage over time of Viper abilities.
* Viper has no way to cancel Death Ward, even through 
Rod of Atos.
Viper
* 
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.
Viper
* 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).
Viper
* 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
Viper
* 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.
Viper
* 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.
Viper
* 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.
Viper
* 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.
Enchantress
* Heroes with little health or magic resistance are easily picked off with Oracle's magic burst, such as Skywrath Mage, 
Crystal Maiden, or Enchantress.
Enchantress
* Heroes with nukes: Bane, Lich, Lion, Skywrath Mage
Viper
* Viper cannot interrupt heroes with powerful channeling abilities: Bane, Enigma, Shadow Shaman, Warlock
Enchantress
* Sand King is a strong ganker, allowing him to shut down squishy heroes in the early game: 
Phantom Assassin, Clinkz, 
Sniper, Enchantress.
Enchantress
* Heroes with haste can negate Enchant's slow: Weaver, Dark Seer, Lycan, Centaur Warrunner.
Enchantress
* Heroes with nukes that can jump her: 
Clockwerk, 
Snapfire, 
Spirit Breaker, 
Techies
Enchantress
* Heroes with break can disable Untouchable for a while: Doom and Shadow Demon (via Aghanim's Scepter), Viper, Shadow Shaman with Hex Breaks talent.
Enchantress
* Heroes with nukes: Bane, Lich, Lion, Skywrath Mage
Additional:
* Untouchable is useless versus constant Arcane Bolts, and it doesn't help that her strength gain is the lowest in the game.
* A jungle Enchantress can weaken lanes and make Skywrath Mage's job easier.
* The magic amplification from Ancient Seal makes her even squishier to Skywrath and his allies' magic nukes.
Enchantress
* Heroes that can jump on her: 
Slark, 
Queen of Pain, Anti-Mage
Additional:
* Queen of Pain often relies more on abilities than right-clicks, making Untouchable nearly useless against her.
* Enchantress also has a lower health pool than Queen of Pain, making her vulnerable to Queen of Pain's damage burst.
Viper
* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, Pugna, Nature's Prophet, Dark Seer, Lycan, Tusk
Enchantress
* Heroes with nukes that can jump her: Clockwerk, Snapfire, Spirit Breaker, Techies
Viper
* 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.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: 
Treant Protector, 
Kunkka, 
Alchemist, 
Troll Warlord, 
Wraith King, 
Tiny, 
Sven.
Enchantress
* 
Battle Trance and 
Fervor can help Troll Warlord deal with Enchantress through Untouchable.
Additional:
* Untouchable's attack speed slow is easily remedied by Fervor stacks and Battle Trance.
* Troll Warlord is a natural Silver Edge carrier, disabling Enchantress' Untouchable.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.
Viper
* 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.
Enchantress
* Heroes that can dominate his illusions or create their own illusions of him: Dark Seer, 
Morphling, Enchantress, Shadow Demon, 
Grimstroke with Aghanim's Scepter.
Viper
* Heroes that can drain mana negatively affect Viper's ability to use Poison Attack, Nethertoxin and Viper Strike: Lion, Anti-Mage
Enchantress
* Heroes that can jump on her: Slark, Queen of Pain, Anti-Mage
Viper
* Viper's skill set makes him an effective early game ganker against Anti-Mage before he is sufficiently farmed.
* Viper's Corrosive Skin and low mana pool causes him to take little damage from Mana Void.
* Nethertoxin disables Mana Break and Counterspell, weakening both his offense and defense.
Viper
* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, Pugna, Nature's Prophet, Dark Seer, Lycan, Tusk
Enchantress
* Heroes with haste can negate Enchant's slow: Weaver, Dark Seer, Lycan, Centaur Warrunner.
Enchantress
* Lycan relies heavily on right clicks making Untouchable very effective against him.
* If he tries to run away Impetus will do huge amounts of damage.
Additional:
* She can Enchant one of the wolves to her side.
* Lycan will struggle greatly to harm Enchantress through her Untouchable which can seriously slow down Lycan's attack speed even if Lycan is spell immune.
Viper
* Nethertoxin prevents the buildup of Jingu Mastery stacks.
* Viper's poison magical damage-over-time stops Monkey King from using Tree Dance. It also ignores the extra armor bestowed by Wukong's Command.
Additional:
* Viper STrike prevents the buildup of 
Jingu Mastery stacks.
* Monkey King's high base movement speed is of little worth against the array of slows Viper possesses.
* All of Viper's magical damage over time stops Monkey King from using 
Tree Dance. It also ignores the extra armor bestowed by 
Wukong's Command.
Enchantress
* Impetus pure damage ignores the extra armor granted from Wukong's Command.
* Enchant can dispel Monkey King's Jingu Mastery bonuses.
* Untouchable makes it hard for Monkey King to land Jingu Mastery stacks.
* 
Sproink allows Enchantress to escape from Wukong's Command.
Viper
* His Poison Attack is very useful against Huskar, since he tends to stay at low health.
* Nethertoxin disables passive skills like Berserker's Blood.
* It is dangerous for Huskar to jump on Viper because Corrosive Skin and Viper Strike with the slowdown of movement and attack speed which usually will be deadly for Huskar.
Additional:
* Viper Strike can disable 
Berserker's Blood, which Huskar relies upon for attack speed and healing.
* The damage from 
Burning Spear and 
Life Break is largely absorbed by Corrosive Skin. It also will return some damage, making it risky to use Burning Spears in the laning stage.
* Because Huskar wants to be on low health for Berserker's Blood, he is particularly vulnerable to Poison Attack.
Enchantress
* Untouchable makes it near impossible to stack Burning Spears.
* Impetus' pure damage puts an instant end to Huskar's low-health brinkmanship.
Viper
* Viper Strike is a strong and breaks Fury Swipes, undispellable slow, making it much easier to kite Ursa for everyone.
Enchantress
* Enchant can dispel 
Overpower.
* Enchant's slow can help kite Ursa in fights and also in lane.
* Enchantress can out harass Ursa in lane by using her long attack range and Untouchable, as well as out sustaining him with Nature's Attendants.
Viper
* Hand of God has a long cooldown, so damage over time spells can be hazardous for Chen, forcing him to use it prematurely: 
Jakiro, Venomancer, Viper, 
Dazzle, 
Phoenix.
Enchantress
* Enchantress can turn Chen's own creeps against him with Enchant. The creeps still keep the health buff Holy Persuasion granted them. Aghanim's Shard gives Enchantress 
Little Friends ability, which allows her to turn multiple of Chen's creeps all at once against him.
* Untouchable and Nature's Attendants make her difficult to kill.
Additional:
* Even though Chen can use 
Holy Persuasion on creeps controlled by Enchant, Enchantress can also use Enchant on Chen's creeps, making it somewhat of a double-edged sword type of matchup.
* Aghanim's Shard gives Enchantress Little Friends ability, which she can use to turn all of Chen's creeps against him for a short time when casted on him.
* Impetus's high burst damage can often kill any of Chen's allies before he can save them with 
Hand of God.
Viper
* Viper Strike breaks Sniper's passives.
* Corrosive Skin allows Viper to deal more damage to Sniper than Sniper deals to him when laning, especially by briefly stepping into Shrapnel.
* Nethertoxin together with Poison Attack can slow Sniper and tears through his low health and mobility.
Enchantress
* Range-reliant heroes: Sniper, 
Drow Ranger
Viper
* Viper can bully Alchemist out of mid lane quite easily, forcing him to either retreat into jungle, or stay harassed in lane, and get very few last hits. Vipers break also completely disables 
Greevil's greed which prevents Alchemist to earn his amazing amounts of money.
Enchantress
* Untouchable greatly reduces Chemical Rage's attack speed advantage.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.
Enchantress
* Against her Untouchable, Sven is barely able to hit Enchantress even with his Black King Bar.
Viper
* Heroes who can harass Omniknight out of lane will keep him weak in the mid game: Viper, Venomancer, Clinkz.
Enchantress
* Impetus is not blocked by 
Guardian Angel. A {U:Satyr Banisher} can also be controlled to dispel Guardian Angel.
Additional:
* Enchantress's Impetus deals pure damage instead of physical damage and ignores Guardian Angel, thus fully negating one of Omniknight's most important abilities for teamfights.
* Similar to Doom, Enchantress can use Enchant on Satyr Banisher, which will give her access to Satyr Banisher's 
Purge, and allow her to remove Heavenly Grace and Guardian Angel.
Viper
* Any hero who can survive Magnus's initiations and manfight him: 
Huskar, 
Faceless Void, Weaver, 
Abaddon, Troll Warlord, Alchemist, 
Dragon Knight, 
Night Stalker, Viper.
Additional:
* Most of Magnus's abilities except 
Empower will trigger damage through Corrosive Skin.
* Poison Attack and Viper Strike can slow Magnus during 
Skewer, as well as putting his 
Blink Dagger on cooldown, preventing him from initiating or re-initiating.
Enchantress
* Heroes that have an escape that doesn't disjoint projectiles: 
Mirana, Faceless Void, 
Magnus
Viper
* 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 usually buys health and armor items for damage. Outside of Black King Bar, Viper will almost always be able to kill her when Refraction is down.
Viper
* Nethertoxin disables Bristleback's passive.
* Viper Strike and Poison Attack slow down Bristleback's movement speed, making him unable to get out from Nethertoxin.
Additional:
* Viper Strike can disable 
Bristleback and prevents 
Warpath from building stacks. Besides losing his defensive passive, Bristleback also loses his ability to build up damage over lengthy battles.
* Viper can perpetually kite Bristleback with Poison Attack and Viper Strike.
Viper
* Nethertoxin breaks the damage block from Bulwark.
* Poison Attack and Viper Strike's slows make it difficult for Mars to contribute to fights due to his low mobility.
Additional:
* Viper Strike can disable 
Bulwark entirely, making Mars far less tanky. Using Nethertoxin inside 
Arena of Blood may discourage enemies from following up with Mars's initiation.
* Rod of Atos is currently common on Viper and keeps Mars in position long enough to be killed.
* However, Viper is not very tanky earlier in the game, so positioning against Mars is important for Viper since a well-timed 
Spear of Mars can be the end of Viper.
Viper
* In the early game, a Dragon Knight without Black King Bar is basically defenseless against Viper.
* Viper can harass Dragon Knight at any time with his Poison Attack and Nethertoxin.
* Corrosive Skin reduces damage from Dragon Fire and inflicts damage to him.
* Viper Strike disables Dragon Blood, negating his main survivability.
* Viper Strike and Poison Attack can severely slow him down even with his Elder Dragon Form.
Additional:
* Dragon Knight is easily harassed by Poison Attack after the laning stage ends.
* Corrosive Skin protects Viper from 
Breathe Fire and returns damage.
* Viper Strike can disable 
Dragon Blood, Dragon's Knight main source of armor and health regeneration.
* Between Poison Attack and Viper Strike, Viper can keep Dragon Knight permanently slowed even in 
Elder Dragon Form.
Viper
* Viper wins on the central line of Puck, because he has a huge damage from the Poison Attack ability, which Puck is not able to constantly avoid using 
Phase Shift, which will give Viper an advantage in the possible damage inflicted on each other
* Puck takes more damage than it does due to the passive Corrosive Skin ability of the Viper, which makes it unprofitable for the Puck to fight against the Viper at an early stage of the game, when the Puck has a very small pool of health.
Additional:
* Viper wins on the central line of Puck, because he has a huge damage from the Poison Attack ability, which Puck is not able to constantly avoid using Phase Shift, which will give Viper an advantage in the possible damage inflicted on each other
* Puck takes more damage than it does due to the passive Corrosive Skin ability of the Viper, which makes it unprofitable for the Puck to fight against the Viper at an early stage of the game, when the Puck has a very small pool of health
Viper
* Nethertoxin disable passives, negating Spectre's damage and survivability by removing both 
Dispersion and 
Desolate.
* Due to 
Haunt and 
Radiance's burn, Spectre is heavily susceptible to being persistently slowed and damaged by Corrosive Skin without even directly attacking Viper.
* Poison Attack and Viper Strike further slow Spectre's movement speed to a crawl, while his improved magic resistance means he can easily shrug off Radiance's burn.
Additional:
* Viper Strike can disable Desolate and Dispersion, leaving Spectre with far less damage output and damage mitigation in engagements.
* Spectre is one of the weakest heroes at early levels. Viper can stifle her farm with early fights before Spectre purchases any major items.
Viper
* Tiny has low movement speed and attack speed, making him vulnerable to Viper's slows.
* Corrosive Skin provides magic resistance to lower Tiny's magic burst damage.
Viper
* Viper does large amounts of magic damage over time, meaning that if a Necrophos uses Ghost Shroud, Viper's abilities will greatly reduce Necrophos survivability, and may actually kill him.
* By the same token, Viper can use his Viper Strike on Necrophos if he attempts to heal himself with Ghost Shroud, and depending on any other effects Necrophos may have from him, (IE:Poison Attack,Corrosive Skin), Viper can often kill Necrophos while he is in his Ghost Shroud.
* Viper's Corrosive Skin helps him take reduced damage from all of Necrophos spells that deal magical damage, which is his only source of damage.
Additional:
* Viper Strike prevents 
Heartstopper Aura from dealing damage or healing Necrophos.
* Viper's magic damage is amplified whenever 
Ghost Shroud is used.
* Corrosive Skin makes Viper tankier against 
Death Pulse and 
Reaper's Scythe.
Viper
* Nethertoxin both Necromastery and Presence of the Dark Lord, reducing his damage massively.
* Corrosive Skin gives Viper bonus Magic Resistance against Shadowraze and Requiem of Souls.
* Viper can easily take advantage of Shadow Fiend's lack of escape and mobility spells with Viper Strike breaks and Poison Attack. Poison Attack also serves as a great way to harass Shadow Fiend.
Viper
* Nethertoxin disables Dawnbreaker's 
Luminosity. Since she's a melee hero, she needs to close gap to attack and Nethertoxin will be bad for her since she cannot heal.
* Viper Strike and Poison Attack will severely slow her down and combined with Nethertoxin, it will be her death sentence (unless her Celestial Hammer or Solar Guardian are off cooldown). Besides that, chasing her down will be easy due to the slow.
Viper
* Viper's Poison Attack and Viper Strike that can slow Razor, and is one of the few heroes that can keep him immobile.
* Altogether, Viper's skills reduce Razor's attack speed, heavily reducing the benefit of the damage drain from Static Link.
Additional:
* 
Storm Surge is counteracted by Viper Strike, leaving Razor without his extra movement speed.
* 
Static Link's damage drain doesn't bother Viper a lot as most of his early to mid game damage is magical.
Viper
* Viper STrike cancels out 
Kraken Shell and stops the hard dispel from passively activating, preventing Tidehunter from functioning as a frontline tank.
* 
Anchor Smash is mostly irrelevant against a ranged hero like Viper.
* Tidehunter relies on the threat of 
Ravage, which has an obscenely long cooldown. Viper can exploit the downtime with his short cooldowns.
Viper
* Corrosive Skin gives Viper additional resistance to Phoenix's magical damage, and since they deal damage over time, Phoenix would be constantly afflicted by his passive's own debuff, making him not an ideal target for Phoenix's harassment. Phoenix's abilities also constantly drain its own health away, becoming more vulnerable to Poison Attack.
Enchantress
* Heroes with nukes that can jump her: Clockwerk, Snapfire, Spirit Breaker, Techies
Viper
* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden, Lion, Huskar, Shadow Shaman, 
Visage, 
Undying, Jakiro.
Enchantress
* Spirit Breaker won’t do much harm to Enchantress because of Untouchable and Nature's Attendants. Unless Enchantress is low on HP, Spirit Breaker won’t be able to catch her with mere spells.
Viper
* Corrosive Skin minimizes the damage Viper takes from all of Ancient Apparition's abilities.
* Ancient Apparition's slow movement speed, squishy nature, and lack of escape abilities can easily be taken advantage of through Poison Attack and Viper Strike.
Viper
* Corrosive Skin minimizes the damage Viper takes from all of Disruptor's skills.
Viper
* Poison Attack makes it hard for Void Spirit to lane against him.
* Corrosive Skin reduces the magical damage from Void Spirit's spells.
Viper
* Viper Strike breaks Multicast.
* Corrosive Skin minimizes the damage from Ignite and Fireblast.
Viper
* Poison Attack and Viper Strike allowing to kite and slow Earthshaker significally, putting Blink Dagger on cooldown and preventing him from initiating or re-initiating.
* Nethertoxin breaks Aftershock. The silence from Level 25 talent also prevents Earthshaker from initiating or re-initiating.
Additional:
* Being a melee hero, Earthshaker's movement is liable to suppression by Poison Attack and Viper Strike.
* Earthshaker's kit, with the exception of 
Enchant Totem, deals magic damage. Corrosive Skin effectively blunts his killing potential with a standard Blink combo among other things.
* Viper Strike can disable 
Aftershock, which removes the stun and bonus damage from Enchant Totem and 
Echo Slam.
Viper
* Viper's poison abilities can slow Bounty Hunter's movement speed and allows to chase him with True Sight items.
* Nethertoxin can break Jinada, and the silence from level 25 prevents Bounty Hunter from using all of his spells.
Viper
* Nethertoxin disables Vengeance Aura.
* Vengeful Spirit has no mobility spells aside from Nether Swap, which Viper can take advantage of with his slows.
* Viper can easily bully Vengeful Spirit out of a lane with Poison Attack.
Additional:
* Viper Strike can disable the attack damage bonus from 
Vengeance Aura and the components of 
Nether Swap.
* Both 
Magic Missile and 
Wave of Terror are counteracted by Corrosive Skin, making Vengeful Spirit's fighting harder against Viper.
Enchantress
* Impetus will deal huge amounts of damage when he uses a 
Fire Remnant to escape.
* 
Flame Guard is useless against Impetus as it deals Pure damage.
* Enchant can be used to dispel Flame Guard.
Viper
* Poison Attack and Viper Strike slows Axe significantly, and puts his Blink Dagger on cooldown, preventing him from initiating. Viper Strike can also break from Counter Helix.
Additional:
* Viper Strike prevents 
Counter Helix from triggering, which significantly lowers Axe's damage output in the early to mid game.
* Viper's various slows and damage over time prevents Axe from initiating as well as putting his Blink Dagger on cooldown.
Viper
* Viper Strike can disable 
Gravekeeper's Cloak, Visage's primary defense mechanism.
* Viper can ignore 
Grave Chill's attack speed slow with his magic damage output.
Additional:
* Since Visage is a slow hero, Viper can easily kite him with Poison Attack and Viper Strike while successfully chipping away at Gravekeeper's Cloak.
* Nethertoxin removes all layers of Gravekeeper's Cloak, leaving Visage exposed.
* Corrosive Skin makes Viper highly resistant to Soul Assumption.
Viper
* Because Poison Attack has almost no cooldown, Aphotic Shield is ineffective as a hard dispel.
* Viper Strike can prevent 
Borrowed Time from activating passively and block 
Curse of Avernus.
Additional:
* Because Poison Attack has almost no cooldown, 
Aphotic Shield is ineffective as a hard dispel.
* Viper Strike can prevent Borrowed Time from activating passively and block Curse of Avernus.
Viper
* 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.
Viper
* Heroes with Attack speed decreasing skills: Jakiro, Viper Lich
Enchantress
* Untouchable will significantly slow down Chaos Knight's physical damage with Phantasm.
* Impetus deals double damage to illusions, making it effective against Phantasm.
Additional:
* Untouchable makes all of Chaos Knight's attacks slow therefore he is unable to deal damage, especially his critical damage of Chaos Strike, also enables Enchantress to escape easily from his attacks.
* However, Reality Rift can still pose a danger to Enchantress because Chaos Knight can decrease a good amount of armor, making it dangerous because of her little armor stat, as he can burst down Enchantress easily if any of Chaos Knight's allies can apply a break on Enchantress.
Enchantress
* Heroes that have an escape that doesn't disjoint projectiles: Mirana, Faceless Void, Magnus
Enchantress
* 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.
* Bear in mind, however, that Timber Chain can also work against Timbersaw if used to escape and that Impetus can ignore 
Reactive Armor if Enchantress is not a primary target for Timbersaw or if he is disabled.
* Timbersaw is a common wielder of 
Lotus Orb, which will allow him to reflect Enchant back at Enchantress and dispel most debuffs as well.
Viper
* Viper Strike prevents Timbersaw from gaining stacks on Reactive Armor.
Enchantress
* Timbersaw has a difficult time against magical and pure damage: Lina, Leshrac, Enchantress, Queen of Pain
Enchantress
* Range-reliant heroes: Sniper, Drow Ranger
Viper
* Heroes with damage-increasing passive abilities, such as Viper and 
Riki, will usually kill Silencer in a short time before he even has time to set up his abilities.
Viper
* Heroes that can apply early pressure before Phantom Assassin has farm are massive threats: 
Axe, Viper, Meepo, Jakiro, Pugna, Slark, Venomancer etc.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.
Enchantress
* Meepo can quickly kill Enchantress with a 
Poof combo, rendering Untouchable useless.
Viper
* Viper Strike prevents the lifesteal from Ransack.
* Meepo and his clones have a lack of magic resistance, so they're vulnerable to Poison Attack & Viper Strike directed onto one clone.
Enchantress
* Enchantress's Untouchable slows down Meepos attacks and Impetus can deal heavy pure damage to a single Meepo, however once Meepo has closed the gap she is an easy target for Poof.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.
Viper
* Illusion or summon-based heroes can be a problem to Viper due to his lack of AoE damage: Naga Siren, Phantom Lancer, 
Beastmaster
Enchantress
* Untouchable negates Inner Beast's attack speed bonus, making her hard to kill even if stunned by Primal Roar.
* Enchantress can also take control of Beastmaster's summons.
Additional:
* Enchant can control Beastmaster's boars with Enchant, mitigating his effectiveness during the laning stage and teamfights.
Enchantress
* Heroes with nukes that can jump her: Clockwerk, Snapfire, Spirit Breaker, Techies
Additional:
* Techies does huge amounts of magical damage, which will bypass Untouchable.
* Enchantress depends on abilities to do damage and heal, which Blast Off's silence prevents.
Viper
* Corrosive Skin will protect Viper from Techies' magical damage.
* Even though Reactive Tazer will disarm Viper if he attacks Techies with Poison Attack, he does lots of damage with his other abilities that can still kill Techies.
Enchantress
* 
Doom with the {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent} talent can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, Enchantress, Huskar, 
Underlord.
Additional:
* 
Devour can easily eat creeps controlled by Enchant, limiting her ganking potential.
* Doom reduces the amount of healing received by Enchantress and her allies from Nature's Attendants. In addition, when Doom chooses the Doom applies Break talent, it can also disable Untouchable.
Viper
* 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.
Enchantress
* Untouchable won't mitigate Venomancer's magical damage, and Enchantress is vulnerable to magic damage.
* Both 
Venomous Gale and 
Poison Nova lower the amount of healing received by Enchantress and her allies from Nature's Attendants.
Viper
* Corrosive Skin means Viper can often outlast Venomancer in a battle of attrition.
* Venomancer has no mobility without items, which makes him vulnerable to constant slows.
Enchantress
* Mirana can instantly kill creeps with Sacred Arrow, making her decent at crippling the armies of Chen or Enchantress.
Enchantress
* Heroes that have an escape that doesn't disjoint projectiles: Mirana, Faceless Void, Magnus
Viper
* 
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.
Viper
* Corrosive Skin makes Viper receive less damage from Invoker's spells
* Viper can harass Invoker with his Poison Attack in the early game.
* Viper Strike and Poison Attack can kill Invoker easily if Ghost Walk is on cooldown.
Enchantress
* Enchantress has a very low health pool, allowing Zeus to burst her down quickly before she can heal off the damage with Nature's Attendants.
* Zeus will not be affected by Untouchable, as he won't try to attack her with right clicks anyway.
* Zeus can stay out of her attack range while trying to kill her, especially if he has bought an 
Aether Lens.
* Most heroes would want to get on top of Zeus to kill him, but Enchantress does not have this option as doing so would severely limit her damage from Impetus.
* The exception is the laning phase, where Enchantress can gank Zeus if she Enchants a good creep.
Additional:
* Enchantress has a very low health pool, allowing Zeus to burst her down quickly before she can heal off the damage.
* Zeus will not be affected by Untouchable, as he won't try to attack her with right clicks anyway.
* Zeus can stay out of her attack range while trying to kill her, especially if he has bought an Aether Lens.
* Most heroes would want to get on top of Zeus to kill him, but Enchantress does not have this option as doing so would severely limit her Impetus damage.
* The exception is the laning phase, where Enchantress can gank Zeus if she Enchants a good creep.
Viper
* Corrosive Skin severely reduces Zeus's damage output throughout the game.
* During the laning stage, Viper can abuse Zeus' reliance on spells by hugging the creep wave. Zeus will take constant damage over time from Corrosive Skin unless he drives Viper from the lane or returns to farming in his absence.
* Prior to buying Blink Dagger or 
Force Staff, Zeus is fragile and possesses low mobility. Any of Viper's numerous slows can set up an easy kill.
Additional:
* Corrosive Skin counters Zeus in lane by canceling the effects of 
Clarity as Zeus relies on Arc Lightning to farm and secure last hits.
* Corrosive Skin also increases Viper's magic resistance to shrug off Zeus's magical nukes.
* Nethertoxin breaks Static Field.
* Due to Zeus' poor mobility, Viper Strike will cripple Zeus and will allow Viper and his teammates to land a lot of attacks.
Enchantress
* Heroes like Enchantress and Chen, or heroes that make use of 
Helm of the Dominator are weak to Crystal Maiden, as Frostbite can do wonders against Enchant, Holy Persuasion, or dominated creeps. Careful though, as an army of carefully controlled creeps (Enchantress and Chen) can hold many stuns that will cancel Freezing Field.
Additional:
* 
Frostbite does 1000 magical damage to Enchantress's creeps and roots them for 10 seconds, which hinders her ability to gank.
Viper
* Heroes who can easily harass Crystal Maiden out of lane in the early game (Clinkz, Viper) can prevent Crystal Maiden from being able to level effectively, and can ultimately slow down her level 6, 12, and 18 to a point where enemy carries already have items to address her ultimate.
Enchantress
* Heroes that can jump on her: Slark, Queen of Pain, Anti-Mage
Viper
* Heroes with Break abilities will prevent Slark from regenerating and gaining Essence Shift stacks: Viper, Shadow Demon, etc.
Additional:
* Viper Strike can disable 
Essence Shift and the regeneration aspect of 
Shadow Dance.
* 
Dark Pact doesn't mean a lot against Viper's ubiquitous slows.
* Viper becomes a relevant presence in team fights before Slark can procure his standard items (e.g. 
Shadow Blade).
Enchantress
* Riki usually buys Diffusal Blade to initiate, which renders Enchantress' movement speed useless, and is usually followed with 
Smoke Screen.
* Riki can effectively hit Enchantress by 
Tricks of the Trade alongside with Diffusal Blade and Smoke Screen's initiation. For a hero like Enchantress, 3 to 4 hits from Riki is a big deal, unless Enchantress built Force Staff earlier.
Viper
* Viper's Nethertoxin disables 
Cloak and Dagger, negating Riki's invisibility and much of his damage. It also makes him more vulnerable to magic damage, which does not go well with Riki's low health pool. With the talent applied, he can't even blink to safety or hide with Tricks of the Trade.
* Corrosive Skin makes it hard for Riki to chase Viper and attack him due to the attack speed slow.
* Viper Strike stays on Riki even after he goes invisible.
* Poison Attack makes it risky for Riki to get last hits and can make the laning phase difficult for him.
Enchantress
* 
Vendetta can deal great damage against her. However, it requires an direct attack, so Nyx Assassin may have difficulties applying Vendetta on her.
* Enchantress's lack of mobility makes her a primary target for ganking with Vendetta.
* 
Mind Flare can deal a great damage against her due to being an Intelligence hero.
* 
Spiked Carapace can reflect Impetus and stun Enchantress.
Additional:
* Spiked Carapace reflects the damage from Impetus.
* Enchantress is a rather squishy hero, making her fall easily to Nyx Assassin's high burst damage.
Viper
* Corrosive Skin minimizes the damage from 
Impale and Mind Flare, and anything else Nyx Assassin tries to throw at Viper.
* Nyx Assassin cannot survive several poison damage-over-time output from Poison Attack, Nethertoxin, Corrosive Skin and Viper Strike, not even while he has Spiked Carapace active. And to make things worse, Nyx Assassin is not a common Silver Edge wielder to counter this problem at all.
Additional:
* Corrosive Skin minimizes the damage from Impale and Mind Flare, and anything else Nyx Assassin tries to throw at Viper.
* Nyx Assassin cannot survive several poison damage-over-time output from Poison Attack, Nethertoxin, Corrosive Skin and Viper Strike, not even while he has Spiked Carapace active. And to make things worse, Nyx Assassin is not a common Silver Edge wielder to counter this problem at all.
Enchantress
* Enchantress has a very small health pool and cannot tank Lina's heavy magic burst.
* Untouchable is decently countered by 
Fiery Soul, exposing Enchantress's weakness to physical damage due to her low armor.
* Lina is decent at clearing creeps and can kill Enchantress's creeps quickly.
Additional:
* Enchantress has pitiful health, and cannot tank Lina's heavy magic damage.
* Untouchable is decently countered by Fiery Soul, exposing Enchantress's weakness to physical damage due to her low armor.
* Lina is decent at clearing creeps and can kill Enchantress' creeps quickly.
Viper
* Viper Strike prevents buildup of Fiery Soul stacks.
* Corrosive Skin provides magic resistance against Lina's spells. However, Lina can counter this with Silver Edge, a common item on Lina.
* Poison Attack and Viper Strike can burn away Lina's small health pool.
Viper
* 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.
Enchantress
* Untouchable prevents Clinkz from harassing Enchantress in lane by lowering his attack speed.
* Nature's Attendants helps Enchantress to sustain through Clinkz's harassment in lane.
Viper
* 
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.
Enchantress
* Since Untouchable pierces Spell Immunity, Lifestealer cannot burst her down even with Rage; meaning she can heal herself back to full HP.
Viper
* 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.
Enchantress
* Untouchable makes her heavily reduce Elder Titan's physical damage output on her without Spell Immunity.
* Enchant can purge 
Astral Spirit's buff without Spell immunity.
* Nature's Attendants can protect her if she survives the full combo and manages to juke around.
Viper
* Viper is kind of a mixed package. Tinker is very good against him. but stands a better chance against him than most heroes.
Corrosive Skin will prevent Tinker from blinking.
Viper Strike and 
Poison Attack will also have a hard time damaging allies through Tinker's constant casting of 
Defense Matrix.
Rearm nor any of Tinker's escape attempts with 
Boots of Travel
* 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
* Viper's
* Viper has no solutions to cancel
* However, if Viper gets a jump on Tinker first. Tinker will unlikely survive versus Viper.
Enchantress
* All of Tinker's damage is magic/pure and completely ignores Enchantress's
Untouchable. And Tinker's nukes can quickly decimate her small HP pool, sometimes even preventing Enchantress from even responding.
* As Enchantress relies solely on her primary attacks to deal damage, and rarely builds something to dispel it, Laser's Blind is particularly effective.
* However, Enchantress will probably build a Linken's Sphere against Tinker's Laser, so getting an additional disable is highly recommended.