Windranger
* 
Ball Lightning can escape quickly fear from 
Focus Fire. Windranger can not reach Storm Spirit although Windrun active catch him.
Additional:
* All abilities from Windranger can not reach from Ball Lightning. Storm Spirit can dodge especially from Powershot and Focus Fire.
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.
Windranger
* All abilities for Morphling can easily escape fear Focus Fire.
* Windranger weakness for agility can easily Morphling destroy against her.
Additional:
* 
Waveform can be used to escape from the reach of Focus Fire and to dodge 
Powershot.
* 
Adaptive Strike (Strength) can be used to stun Windranger even while 
Windrun is active.
* 
Morph is useful to morph into Windranger to copy her abilities.
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.
Windranger
* 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
* Viper is kind of a mixed package. Tinker is very good against him. but stands a better chance against him then 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.
Windranger
* 
Moon Glaives can ignore certain abilities that either trigger on attack or give evasion under the condition that the heroes who have them are not primary targets. Examples include: 
Centaur Warrunner, 
Windranger, 
Phantom Assassin, 
Hoodwink etc.
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.
Windranger
* Windranger's has bad against Hero heavily strong escape out of reach with windrun: 
Spirit Breaker, 
Lycan, 
Storm Spirit, 
Earth Spirit
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
Windranger
* With 
Bloodthorn, Clinkz becomes a strong counter to heroes who rely on evasion and blind such as Windranger, Phantom Assassin, 
Troll Warlord and 
Keeper of the Light.
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
Additional:
* 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.
Windranger
* With 
Normal Punch from 
Aghanim's Scepter, Dark Seer can gain an advantage against heroes who rely on evasion as Normal Punch has true strike: Phantom Assassin, Windranger, Hoodwink.
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
Windranger
* 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
* Heroes that can drain mana negatively affect Viper's ability to use Poison Attack, Nethertoxin and Viper Strike: Lion, 
Anti-Mage
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.
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.
Windranger
* 
Stampede can help his teammates escape from Windrun and Focus Fire.
* 
Retaliate will shred through Windranger's health if she chooses to attack him during Focus Fire.
Additional:
* Focus Fire grants Windranger a massive attack speed bonus, while her attack damage is generally quite low. This, combined with Windranger's low health pool and armor, makes Retaliate do absolutely massive damage over a short time, making Centaur a hero she can never expect to kill or harass.
* Windrun grants evasion, but Centaur Warrunner does not rely on successful attacks in order to do damage. Hoof Stomp, Double Edge, and Stampede all do large amounts of magical damage and can completely demolish Windranger in a moment.
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.
* 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.
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.
Windranger
* Windrun triggers the damage from Rupture.
Additional:
* 
Rupture turns Windranger's mobility against her.
* 
Blood Rite's silence makes Windranger totally useless, since she's extremely reliant on abilities.
Windranger
* 
Time Walk fast cooldown and will avoided from Focus Fire fast. Additionally, Faceless Void must not Time Walk reverse since build Aghanim's Shard for fear of Shackleshot.
* 
Time Dilation makes Windrun movement speed slowed useless.
* 
Chronosphere render Windranger's to never escape Windrun or attacking from Focus Fire to His and locked inside Chronosphere foolproof from his attacking her from inside Chronosphere.
Additional:
* Time Dilation while renders Windrun movement speed useless slow.
* Time Walk fast cooldown can escaping avoided to Focus Fire. Additionally, Time Walk can dodge to Powershot
* Chronosphere trap can attacking Windranger can not escaping with Windrun.
Windranger
* Windrun does not protect Windranger from 
Cursed Crown stun or Dark Willow's magical nukes.
* Focus Fire cannot target Dark Willow in 
Shadow Realm and will be interrupted if targeted earlier, wasting the ultimate.
Additional:
* Windrun does not protect Windranger from Cursed Crown's stun or Dark Willow's magical nukes.
* Focus Fire cannot target Dark Willow in Shadow Realm and will be interrupted if targeted earlier, wasting the ultimate.
Windranger
* 
Rolling Thunder can help escaping from Focus Fire and Windrun reach.
* Disarm from 
Lucky Shot makes Focus Fire temporarily useless.
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.
Windranger
* Shadow Demon can waste precious seconds of Windrun with 
Disruption.
* Alternatively, 
Demonic Purge. can be used to dispel it altogether, leaving her completely defenseless.
* Disruption can be used to save an ally if they get stunned by Shackleshot.
Additional:
* Shadow Demon can waste precious seconds of Windrun with Disruption.
* Alternatively, Demonic Purge can be used to dispel it altogether, leaving her completely defenseless for 7 seconds.
* Disruption can be used to save an ally if they get stunned by 
Shackleshot.
Windranger
* Dream Coil leash can stop and stunned moving from Windrun.
* Combinated Wanning Rift and build Blink Dagger can easily avoid from Focus Fire
Windranger
* Power Cogs trap prevent Windranger from fleeing with Windrun.
* Battery Assault repeatedly interrupts Focus Fire, disrupting Windranger's damage output.
Additional:
* Power Cogs prevent Windranger from fleeing with Windrun.
* Battery Assault repeatedly interrupts Focus Fire, disrupting Windranger's damage output.
Windranger
* Drow Ranger build 
Shadow Blade can avoided from Focus Fire and upgrade with Silver Edge can also break from Windrun.
* 
Hurricane Pike allows her to close the gap and deal immenese damage and provides decent stats to her.
Additional:
* A well-timed from 
Gust is impossible Windranger's can not escaping from Windrun.
* Combinating 
Frost Arrows and 
Eye of Skadi will Windrun movement speed slow.
* Hurricane Pike allows Her to close the gap and deal damage from Focus Fire provides decent ststs to her.
* Drow Ranger build item Shadow Blade or Silver Edge makes easily two conditions from her can break from Windrun or avoided from Focus Fire and combinating build 
Nullifier in lategame makes Windranger's weakness from Windrun useless in lategame.
Windranger
* The high mobility provided by 
Fire Remnant makes it hard for Windranger to find a good position to land Shackleshot or a full duration of Focus Fire.
* 
Flame Guard and 
Searing Chains deal considerable magical damage to Windranger which she cannot avoid with Windrun.
* Searing chains also negates the mobility from Windrun.
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).
Windranger
* 
Slardar with 
Corrosive Haze.
* Windrun invisibility via Aghanim's Scepter is very risk from Windranger against Hero True Sight abilities
* 
Bounty Hunter with 
Track.
* Slardar with Corrosive Haze.
* 
Bloodseeker with 
Thirst.
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
Viper
* Ranged heroes will have a hard time hitting enemies inside Magnetic Field: 
Silencer, Viper.
Viper
* Viper cannot interrupt heroes with powerful channeling abilities: 
Bane, 
Enigma, 
Shadow Shaman, 
Warlock
Viper
* Viper cannot interrupt heroes with powerful channeling abilities: Bane, Enigma, Shadow Shaman, Warlock
Windranger
* 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.
Windranger
* Windranger heavily relies on her abilities for any form of tactical advantage and damage. A well timed silence will make her useless: 
Puck,Silencer, 
Death Prophet, Skywrath Mage, 
Drow Ranger, Earth Spirit, 
Grimstroke.
Windranger
* Windranger heavily relies on her abilities for any form of tactical advantage and damage. A well timed silence will make her useless: Puck,Silencer, Death Prophet, Skywrath Mage, Drow Ranger, Earth Spirit, Grimstroke.
Windranger
* Windranger's has bad against Hero heavily strong escape out of reach with windrun: Spirit Breaker, Lycan, Storm Spirit, Earth Spirit
Windranger
* 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
* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, Pugna, Nature's Prophet, Dark Seer, Lycan, Tusk
Additional:
* Viper Strike can be countered through Snowball, wasting Viper's mana through his ultimate.
* Nethertoxin is useless against Tusk as he has no passive abilities at all. And to make things worse, Nethertoxin cannot disable 
Walrus PUNCH! because it's an auto-cast ability.
Windranger
* Counterspell can reflects triggering with Focus Fire. Since Focus Fire target against Anti-Mage, Focus Fire damage can return to Anti-Mage easily destroy to Windranger's.
* Anti-Mage items 
Abyssal Blade and 
Monkey King Bar can useful for Anti-Mage's and easily complicated escaping Windranger's fighting against Anti-Mage's and also bypasses to Windrun evasion.
Additional:
* 
Counterspell can reflect Windranger's targeted spells such as Shackleshot and Focus Fire back to her.
* 
Blink can be used to avoid Shackleshot and Powershot, assuming an Anti-Mage player can react fast enough.
* 
Mana Break and 
Mana Void can punish high mana pool for Windranger's.
Viper
* Heroes that can drain mana negatively affect Viper's ability to use Poison Attack, Nethertoxin and Viper Strike: Lion, 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
* Illusion or summon-based heroes can be a problem to Viper due to his lack of AoE damage: 
Naga Siren, 
Phantom Lancer, 
Beastmaster
Viper
* Heroes with extremely slow movement speed will cripple against Solar Bind: 
Medusa, Viper
Viper
* Viper cannot interrupt heroes with powerful channeling abilities: Bane, Enigma, Shadow Shaman, Warlock
Windranger
* 
X Marks The Spot can easily escape Windrun turn the position and combo with 
Torrent or 
Ghostship trap. Additionally, Kunkka build Aghanim's Scepter 
Torrent Storm create Windranger's difficulty escaping.
Additional:
* Windranger can't escape Windrun X Marks the Spot with combo Torrent or Ghostship trap.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: 
Treant Protector, 
Kunkka, 
Alchemist, Troll Warlord, 
Wraith King, 
Tiny, 
Sven.
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.
* 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.
Windranger
* As long as Windranger is able to identify the real hero among the illusions, heroes relying on them can be easily tagged with Focus Fire: 
Chaos Knight, 
Terrorblade, Phantom Lancer, Naga Siren.
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.
Windranger
* 
Glaives of Wisdom can easily stealing permanently intelligence for Windranger's.
* Silencer's abilities hamper Windranger's effectiveness in battle, preventing her from comboing abilities and escaping using Windrun.
Additional:
* Silencer's abilities hamper Windranger's effectiveness in battle, preventing her from comboing abilities and escaping using Windrun.
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
* Voodoo Restoration heals to counter damage over time of Viper abilities.
* Viper has no way to cancel Death Ward, even through 
Rod of Atos.
Windranger
* Death Ward's first target (before it bounces) can evade it, therefore Windranger and Phantom Assassin are poor choices to use it on.
Viper
* 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.
Additional:
* 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.
Windranger
* As long as Windranger is able to identify the real hero among the illusions, heroes relying on them can be easily tagged with Focus Fire: Chaos Knight, Terrorblade, Phantom Lancer, Naga Siren.
Windranger
* Windranger can avoid Ursa's primary source of damage, 
Fury Swipes, by simply using Windrun. The slow from 
Earthshock is also rendered irrelevant by Windrun.
* Focus Fire and Windrun can be used to kite Ursa.
Additional:
* Ursa relies on the Blink-Earthshock combo to slow enemies to burst them, but Windranger can use Windrun to escape through Earthshock's duration.
* Windrun and Focus Fire can easily allow Windranger to kite Ursa and do good amounts of damage in the process.
Viper
* Nethertoxin breaks Fury Swipes, making Viper a decent counter to Ursa in a laning stage.
* Viper Strike is a strong, undispellable slow, making it much easier to kite Ursa for everyone.
Windranger
* Windranger's Focus Fire tears apart Templar Assassin's refraction very quickly and easily bursts her down due to her low health pool against Windranger's immense attack speed.
* Templar Assassin's Psionic Trap doesn't slow down Windranger due to her skill Windrun.
* Templar Assassin's high damage can also be easily evaded thanks to Windrun's 100% evasion.
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 traditionally forgoes health and armor items for damage. Outside of Black King Bar, Viper will almost always be able to kill her when Refraction is down.
Windranger
* Focus Fire can quickly attack target Meepo or clones instanly. Additionally, Windranger's can use combinated Shackleshot and Focus Fire since Poof wrong landing and stunned from Shackleshot affected Meepo and clones collateral damege from Focus Fire
* Escaping from Windrun make Earthbind roots can not reach.
Viper
* Nethertoxin 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.
Windranger
* Windrun can be used to dodge Earthshaker's abilities if Windranger has a quick reaction time.
* Focus Fire and Windrun allows Windranger to kite Earthshaker.
* A Windranger with fast fingers can prevent Earthshaker from using 
Fissure with Shackleshot.
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.
* Nethertoxin disables 
Aftershock, which removes the stun and bonus damage from Enchant Totem and 
Echo Slam.
Windranger
* Windranger prevents Huskar from landing 
Burning Spears by using Windrun.
* Because Huskar tends to be at low health, Focus Fire and Powershot are good abilities against him.
Additional:
* Windrun makes it impossible to hit Windranger with Burning Spears.
* Huskar cannot toggle 
Armlet of Mordiggian to regain health while taking constant damage from Focus Fire.
Viper
* Nethertoxin disables 
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.
Additional:
* 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.
Windranger
* 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
* Heroes with break can disable Untouchable for a while: 
Doom and 
Shadow Demon (via Aghanim's Scepter), Viper, Shadow Shaman with Hex Breaks talent.
Windranger
* Other heroes that rely on physical attacks to deal damage and not their abilities: Troll Warlord, 
Sniper, 
Monkey King, Sven.
Additional:
* Powershot destroys the tree Monkey King is standing on.
* Monkey King's natural reliance on trees makes him an easy target for Shackleshot.
* Windrun evades Monkey King's attacks, preventing him from building up Jingu Mastery.
Viper
* Nethertoxin 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.
Additional:
* 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.
Windranger
* Other heroes that rely on physical attacks to deal damage and not their abilities: Troll Warlord, Sniper, Monkey King, Sven.
Viper
* Nethertoxin 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.
* Viper Strike together with Poison Attack can slow Sniper and tears through his low health and mobility.
Windranger
* Heroes with mobility/escape mechanisms to dodge Ancient Apparition abilites, or to easily jump on him: Riki, 
Queen of Pain, Phantom Assassin, Windranger, Bounty Hunter, Spirit Breaker, 
Night Stalker, Storm Spirit, 
Juggernaut, etc.
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.
Windranger
* Phantom Assassin's 
Blur will be useless if Windranger managed to get Monkey King Bar or Bloodthorn, and other than Stifling Dagger, Phantom Assassin has no abilities that can bypass Windrun.
* Additionally, Phantom Assassin doesn't like building Monkey King Bar because her crits are reliant on attack damage.
* Focus Fire can still deal considerable damage despite Blur's evasion due to the increased attack speed.
Viper
* Heroes that can apply early pressure before Phantom Assassin has farm are massive threats: 
Axe, Viper, 
Meepo, Pugna, 
Slark etc.
Windranger
* Other heroes that rely on physical attacks to deal damage and not their abilities: Troll Warlord, Sniper, Monkey King, Sven.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.
Windranger
* Heroes with evasion will cause Chen and his creeps to struggle in attacking them and will waste much of Penitence's power: Phantom Assassin, Windranger, Hoodwink.
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.
Viper
* Nethertoxin prevents Timbersaw from gaining stacks on Reactive Armor.
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.
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
* Nethertoxin disables 
Bulwark entirely, making Mars far less tanky. Using Nethertoxin inside 
Arena of Blood may discourage enemies from following up with Mars' initiation.
* Rod of Atos is currently common on Viper and keeps Mars in position long enough to be killed.
* Beware that Viper is not very tanky earlier in the game, so positioning against Mars is important since a well-timed 
Spear of Mars can be the end of Viper.
Additional:
* 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.
Windranger
* Powershot can destroy the trees to prevent 
Scurry's passive as well as end 
Bushwhack prematurely or prevent it completely.
* 
Acorn Shot creates a tree for Windranger to get an easy Shackleshot off.
* Acorn Shot does not grant True Strike, thus making it easy for Windranger to evade it with Windrun.
* Shackleshot stuns Hoodwink for a lengthy duration due to her often reliance on positioning with trees.
Additional:
* Powershot can destroy the trees to prevent Scurry's passive as well as end Bushwhack prematurely or prevent it completely.
* Acorn Shot does not grant True Strike, thus making it easy for Windranger to evade it with Windrun.
* Shackleshot stuns Hoodwink for a lengthy duration due to her often reliance on positioning with trees.
Viper
* Dragon Knight is easily harassed by Poison Attack after the laning stage ends.
* Corrosive Skin protects Viper from 
Breathe Fire and returns damage.
* Nethertoxin mitigates 
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.
Additional:
* 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.
* Corrosive Skin reduces damage from Dragon Fire and inflicts damage to him.
* Nethertoxin disables Dragon Blood, negating his main survivability.
* Viper Strike and Poison Attack can severely slow him down even with his Elder Dragon Form.
Viper
* Corrosive Skin minimizes the damage Viper takes from all of Disruptor's skills.
Viper
* Most of Magnus' 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.
Windranger
* Windrun quickly dodge Mirana's Sacred Arrow and misses her attacks.
* Shackleshot through tree with Focus Fire via Aghanim's Scepter​ combo can kill Mirana quickly, before using Leap or Moonlight Shadow.
Windranger
* {Ability ID:Windrun|Windranger|16px} negates the damage from {Ability ID:Omnislash|Juggernaut|16px}.
* {Ability ID:Windrun|Windranger|16px} gives Windranger enough movement speed to get out of {Ability ID:Blade fury|Juggernaut|16px} range.
* {Ability ID:Focus fire|Windranger|16px} goes through {Ability ID:Blade Fury|juggernaut|16px}.
Windranger
* Pudge relies on his hook to initiate his combo. As long as she's able to avoid the hook with Windrun and shackle him, Windranger can take him down easily. Pudge's low armor means that he won't be able to endure Focus Fire for long.
Viper
* Nethertoxin breaks 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 and Poison Attack. Poison Attack also serves as a great way to harass Shadow Fiend.
Viper
* Nethertoxin breaks Multicast.
* Corrosive Skin minimizes the damage from Ignite and Fireblast.
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.
Viper
* Because Poison Attack has no cooldown, 
Aphotic Shield is ineffective as a hard dispel.
* Nethertoxin prevents 
Borrowed Time from activating passively and blocks 
Curse of Avernus
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 Nercophos spells that deal magical damage, which is Necrophos's only source of damage.
Additional:
* Nethertoxin 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 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 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.
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:
* Nethertoxin prevents 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.
Viper
* Nethertoxin cuts off 
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
* 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.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.
Viper
* Heroes who can harass Omniknight out of lane will keep him weak in the mid game: Viper, Venomancer, Clinkz.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.
Windranger
* 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
* Nethertoxin prevents buildup of Fiery Soul stacks.
* Corrosive Skin provides magic resistance against Lina's spells.
* Poison Attack and Viper Strike can burn away Lina's small health pool.
Windranger
* Bounty Hunter with Track.
* Windrun invisibility via Aghanim's Scepter is very risk from Windranger against Hero True Sight abilities
* Bounty Hunter with Track.
* Slardar with Corrosive Haze.
* Bloodseeker with Thirst.
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.
Windranger
* 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
* 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.
Additional:
* 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.
Windranger
* Sven with Aghanim's Scepter can easily chase down Windranger and dispel her Windrun at the same time.
Windranger
* Other heroes that rely on physical attacks to deal damage and not their abilities: Troll Warlord, Sniper, Monkey King, Sven.
Viper
* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.
Viper
* 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.
Additional:
* 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.
Windranger
* As long as Windranger is able to identify the real hero among the illusions, heroes relying on them can be easily tagged with Focus Fire: Chaos Knight, Terrorblade, Phantom Lancer, Naga Siren.
Viper
* Heroes with Attack speed decreasing skills: Jakiro, Viper 
Lich
Windranger
* 
Doom can shut down all active abilities from Windranger while can not escape with Windrun and Focus Fire since activated with Doom.
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.
Windranger
* Kraken Shell easily dispels the lengthy stun from Shackleshot.
* Kraken Shell (and possibly Anchor Smash) blocks huge amount of damage from Focus Fire.
* Anchor Smash is one of the few sources of True Strike, which means Tidehunter can deal significant damage through Windrun, while also reducing Windranger's damage output.
Viper
* Nethertoxin 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.
* Tidehunter relies on the threat of 
Ravage, which has an obscenely long cooldown. Viper can exploit the downtime with his short cooldowns.
Windranger
* Void Spirit deals entirely magical damage in the early game, ignoring her evasion from Windrun.
* A Void Spirit with fast reaction time can use Dissimilate or Astral Step to dodge Powershot.
Additional:
* Void Spirit deals entirely magical damage in the early game, ignoring her evasion from Windrun.
* A Void Spirit with fast reaction time can use Dissimilate or Astral Step to dodge Powershot.
Viper
* Poison Attack makes it hard for Void Spirit to lane against him.
* Corrosive Skin reduces the magical damage from Void Spirit's spells.
Windranger
* Static Link can lower the damage output from Focus Fire.
* Eye of the Storm strikes cannot miss, even if Windrun is active.
Additional:
* 
Static Link greatly lowers Windranger's damage output from Focus Fire.
* 
Eye of the Storm strikes cannot miss, even if Windrun is active.
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 Nethertoxin, leaving Razor without faster MS.
* Static Link's damage drain doesn't bother Viper a lot as most of his early to mid game damage is magical.
Windranger
* Focus Fire potentially trigger with 
Quill Spray very harassing and passive abilities from Bristleback 
Bristleback and 
Warpath stacked damage. Additionally,Combination Quill Spray and 
Blade Mail is very possible kill her's since Windranger's activated Focus Fire. At the same time,Windrun does not protect from Quill Spray.
* Bristleback's tanky in late game build 
Heart of Tarrasque and 
Vanguard until upgrade 
Crimson Guard or Abyssal Blade is very difficult for Windranger's kill Bristleback and her can need more damage.
* Spamming 
Viscous Nasal Goo is very harder Windranger's Windrun movement speed. Bristleback combinating build 
Assault Cuirass also render Windranger's loss armor.
* Bristleback must build 
Lotus Orb cause make reflects Windranger's target hard Shackleshot and Focus Fire.
Additional:
* Combo Quill Spray and items Blade Mail can easily trigger from Focus Fire damage.
Viper
* Nethertoxin disables 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.
Additional:
* Nethertoxin disables Bristleback's passive.
* Viper Strike and Poison Attack slow down Bristleback's movement speed, making him unable to get out from Nethertoxin.
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.
Windranger
* Windranger's highly mobile playstyle allows her to easily control Lifestealer from a distance, as he has no disables on his own. Windrun not only provides her with bonus move speed, but evasion as well, undoing Lifestealer's ability to attack her. In combination with Focus Fire, Windranger can easily dispose of Lifestealer without him being able to reach her.
Windranger
* Pounce's leash prevents Windranger from use Windrun,making hard for Windranger escape from Slark. Additionally, Pounce charge upgraded to Aghanim's Scepter also avoided catch from Windrun.
* Shadow Dance combinated Shadow Blade and also upgrade Silver Edge can avoid Windranger's attack from Focus Fire.
* Dark Pact will dispell from stunned Shackleshot.
Viper
* Nethertoxin negates 
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).
Windranger
* Windranger's has bad against Hero heavily strong escape out of reach with windrun: Spirit Breaker, Lycan, Storm Spirit, Earth Spirit
Viper
* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, 
Arc WardenLion
Windranger
* Windrun does not provide protection against 
Counter Helix and 
Berserker's Call. Her fast attack speed with Focus Fire will also quickly trigger Counter Helix multiple times.
Viper
* Poison Attack and Viper Strike slows Axe significantly, and puts his Blink Dagger on cooldown, preventing him from initiating.
* Nethertoxin can break Counter Helix.
Additional:
* Nethertoxin 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.
Windranger
* Spectre can instantly escape Focus Fire or hunt a Windranger with 
Haunt.
* Spectre can catch up to her with 
Spectral Dagger, even if she uses Windrun.
* 
Desolate allows Spectre to hit Windranger through Windrun.
* 
Dispersion combined with Blade Mail and or Vanguard before Vanguard upgrade to Abyssal Blade makes Spectre tanky and or also reflects some damage back to Windranger.
Additional:
* Spectre can catch up to her with Spectral Dagger, even if she uses Windrun.
* Spectre can instantly reach a ratting Windranger with Haunt.
* Dispersion can reflect some of her damage, especially from her Focus Fire.
Viper
* Nethertoxin disables 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.
Additional:
* 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.
Windranger
* Due to lack of magic resistance, Venomancer abilities eats through Windranger's health.
* Venomancer's multiple slows, to an extent, negates Windrun's mobility.
Additional:
* Due to lack of magic resistance, Venomancer poisons eats through Windranger's health.
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.
Windranger
* Jakiro's reliance on his abilities can cause struggles for heroes who rely on evasion or blinds to get upper hand: Phantom Assassin, Windranger, Riki, Troll Warlord, Keeper of the Light.
Windranger
* Heroes with good counter-push abilities to clear creep waves can hinder Jakiro's early pushing ability: Death Prophet, Sniper, Tinker, Windranger.
Viper
* Illusion or summon-based heroes can be a problem to Viper due to his lack of AoE damage: Naga Siren, Phantom Lancer, Beastmaster
Additional:
* 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.
Windranger
* As long as Windranger is able to identify the real hero among the illusions, heroes relying on them can be easily tagged with Focus Fire: Chaos Knight, Terrorblade, Phantom Lancer, Naga Siren.
Windranger
* Many of Nyx Assassin's abilities are good against Windranger.
* 
Impale is great for stunning Windranger and allowing additional disables to be landed.
* 
Mind Flare is useful against Windranger's decent intelligence growth.
* 
Spiked Carapace is easy to use against Powershot.
* 
Vendetta allows Nyx Assassin to sneak up on and deal massive damage to Windranger without giving Windranger a chance to use Windrun to evade it.
* Nyx Assassin's item build allows him to easily deal with Windranger.
Viper
* Corrosive Skin minimizes the damage from Impale and Mind Flare.
* Nyx Assassin cannot survive several poison damage-over-time, even Spiked Carapace is activated.
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.
Windranger
*
Press The Attack can save allies dispell from Shackleshot.
Duel can lock before escape with Windrun.
Blade Mail can Windranger's useless.
*
* Focus Fire potentially trigger with
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.
Poison Attack.
* Press the Attack can dispel
* Viper slows can easily negate by Overwhelming Odds movement speed.