* Nethertoxin breaks Sniper's passives.
* Viper Strike together with Poison Attack can slow Sniper and tears through his low health and mobility.

* Haunt instantly allows her to get up and close with Sniper, and Spectral Dagger makes it difficult to escape from her.
* Spectre outcarries Sniper in the late game, so Sniper must try to end the game early before Spectre comes online.
Additional:
* Spectre can reach him easily in the backlines with Spectral Dagger or teleport to him with Haunt.
* He is usually a fair distance away from his allies, so Desolate will quickly tear Sniper down.

* 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.

* Spectral Dagger and Haunt allow Spectre to get close to Lina.
* Desolate is very strong against Lina, who's usually a bit isolated in fights because of her high attack and cast range.
* Dispersion can mitigate a good portion of Lina's burst damage, allowing Spectre to turn on her afterwards.
Additional:
* Spectre can very easily close the distance on Lina with Haunt and Spectral Dagger, and due to Lina's abysmal mobility without a Blink Dagger and terrible health pool and armor, Lina easily gets slaughtered due to Desolate.
* Dispersion can mitigate a good portion of Lina's burst damage, allowing Spectre to turn against her afterwards.

* Dispersion makes Spectre very tanky, making it much less likely for Axe to bring her low enough for Culling Blade.
* Spectre can simply use Spectral Dagger to escape against an Axe gank.

* 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.

* Spectral Dagger can be used to traverse past Fissure.
* Haunt will usually disable Earthshaker's Blink Dagger prior to a teamfight, preventing him from initiating.
* On the other hand, Haunt will amplify damage done from Echo Slam. Use this to your advantage.
Additional:
* Spectre can use Haunt to intercept and disrupt Earthshaker's initiation attempts.
* Spectral Dagger can be used to traverse past Fissure.
* Earthshaker often travels alone when he is trying to initiate, so Desolate can be very effective against him.
* Beware that the Haunt illusions amplify the damage done from Echo Slam, which can prove fatal for Spectre's own team.

* 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. Additionally the level 25 talent will silence Earthshaker, making him vulnerable to Viper's teammates without stuns.

* Spectre can instantly reveal Bounty Hunter's position on the activation of her ultimate Haunt. She can also semi-reveal(visible but not target-able) Bounty Hunter by hitting him with Spectral Dagger.

* 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 preventing Bounty Hunter from using all of his spells.

* Spectre can use Haunt to intercept and disrupt Magnus's initiation attempts.
* Spectral Dagger can severely slow down Magnus after he uses Skewer.
* Magnus often travels alone when he is trying to initiate, so Desolate can be very effective against him.
Additional:
* Spectre disables Magnus' Blink Dagger using her ultimate, and later into the game can usually outlive Reverse Polarity's duration.

* 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.

* 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.

* As Ancient Apparition likes to stay far away from the fight to get full effectiveness from Ice Blast, he is a very good target for a Haunt gank. Ancient Apparition also has no hard disables and escape spells, making him an easy kill for Spectre.

* Spectral Dagger hinders Sven's low movement speed, and can be an easy tool to escape against his high damage.
* Dispersion makes it harder for Sven to burst down Spectre in one on one fights, and can reflect Sven's high damage back to him or his nearby teammates.
* Haunt and Radiance disables Sven's Blink Dagger.
* Desolate's pure damage ignores Sven's high armor.
* Spectre should not attempt to stand up to a full slotted Sven, since she will get shredded.

* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.

* Spectral Dagger give vision over Slark, slows strong with the talent, can not be dispelled and can not be missed if targeted. With the cooldown reduction talent Spectre can keep constant vision over slark, so he has to use his Shadow Dance to disengage so he cant be targeted by the dagger, which can still latch on to him when ground targeted.
* Spectre deals a lot of AOE damage in teamfights which still goes through Shadow dance.

* 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).

* Nethertoxin breaks Phantom Assassin's passive skills.
* Viper Strike goes through Black King Bar.

* Black King Bar is useless, since all of the Spectre's abilities go through spell immunity,
* Phantom Assassin's Blur cannot evade Desolate because its damage is a separate damage instance and is applied before the attack hits.
* Spectre's high durability provided by Dispersion and damage block items makes her one of the hardest carries to take down.
Additional:
* Dispersion makes it hard for Phantom Assassin to burst down Spectre while also reflecting back Phantom Assassin's high burst damage against herself.
* Desolate ignores the evasion from Blur.
* Black King Bar is useless against Spectre as all of her skills pierce spell immunity.

* Heroes that rely on evasion are slightly countered by Desolate: Phantom Assassin, Troll Warlord.

* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.

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

* 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.

* Tiny has low movespeed and attack speed, making him vulnerable to Viper's slows.
* Corrosive Skin provides magic resistance to lower Tiny's magic burst damage.

* 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.

* Spectral Dagger maintains vision on Monkey King, and allows Spectre to chase Monkey King into the trees.
* Haunt will still spawn an illusion next to Monkey King while under the effects of Mischief, removing the disguise.
* Monkey King attack range is exactly 300. The best range for Dispersion buff.

* 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:
* 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.

* In the early game, a Dragon Knight without Black King Bar is basically defenseless against Viper.
Additional:
* 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.

* Nethertoxin prevents Timbersaw from gaining stacks on Reactive Armor with silence talent also prevents Timbersaw using his abilities.

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

* His global teleportation with Boots of Travel and Rearm is easily countered with Haunt, and Spectre can reach him anywhere on the map.
* He is squishy, and if alone Desolate will kill him very fast.
* Laser's blind isn't reliable, since Desolate cannot miss.

* 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.

* Oracle's burst damage is ineffective against Dispersion.
* Disarm provided by Fate's Edict is not as significant debilitation for Spectre as it might be for other carries since She can do damage even without landing attacks.

* 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.

* Spectral Dagger follows Riki even after he goes invisible and stays on him through Tricks of the Trade, revealing his location.
* Desolate grants Spectre the ability to damage Riki with right clicks regardless of Smoke Screen's blind.
* Riki relies on his high damage to kill is opponents, which is countered by Dispersion.
* Haunt can find Riki globally at any time, negating much of his ganking potential.

* 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:
* 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.

* Corrosive Skin minimizes the damage from Impale and Mana Burn.
* Nyx Assassin cannot survive several poison damage-over-time, even Spiked Carapace is activated.
* However the Vendetta break can be dangerous for Viper.

* Because Poison Attack has a low cooldown at all levels, Aphotic Shield is ineffective as a hard dispel.
* Nethertoxin prevents Borrowed Time from activating passively and blocks Curse of Avernus

* 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.

* As Crystal Maiden is squishy with very bad movement speed, Spectre can easily stay on Crystal Maiden with Haunt and Spectral Dagger.
* Late game, with enough farm, Spectre can withstand an entire Freezing Field, possibly even causing Crystal Maiden to kill herself from Dispersion.

* 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.

* 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 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.

* Nethertoxin breaks Multicast.
* Corrosive Skin minimizes the damage during Ignite and Fireblast.

* Spectre can easily close the distance on Drow Ranger with Haunt and stick on her with Spectral Dagger, negating the bonus agility from Marksmanship.

* 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.

* Zeus can deal a huge amount of damage, but he lacks defensive abilities, such as good mobility or resistance. Due to that, he doesn't like to be touched by any means. Heroes with higher damage output and good mobility will often get easily near Zeus and trade damage (eventually causing Zeus's downfall). Such Heroes include: Lycan, Slark, Storm Spirit, Spectre and others.

* 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.

* Heroes with break can disable Untouchable for a while: Doom and Shadow Demon (via Aghanim's Scepter), Viper

* Spectre's entire ability set is designed to get to and destroy heroes that stay in the backlines, both carries (like the aforementioned Drow Ranger and Sniper) and supports (like Dazzle and Shadow Shaman).

* 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.

* 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.

* 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.

* 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 makes Spectre tanky and 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.
* Windrun's miss chance is countered by Desolate.

* Heroes that create illusions (such as 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 and the aforementioned 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).

* 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.

* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden

* Enemies that possess high defenses through magic resistance, damage reduction, or high regeneration will make it difficult to whittle their health down to get to Reaper's Scythe's threshold. Such heroes include Bristleback (although only from behind), Spectre, Ursa, and Dragon Knight.

* 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.

* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.

* Nature's Prophet can literally do nothing against Spectre, because she can chase him from anywhere with Haunt.
* Spectre, just like Naga Siren loves buying Radiance, which can kill Nature's Prophet's treants, and grant her farm simultaneously.
Additional:
* Spectre can get to him anywhere on the map with Haunt.
* Spectre can pass through his trees with Spectral Dagger.
* Desolate's damage will melt him quickly, as he's alone most of the time.

* Corrosive Skin minimizes the damage Viper takes from all of Disruptor's skills.

* Poison Attack makes it hard for Void Spirit to lane against him.
* Corrosive Skin reduces the magical damage from Void Spirit's spells.

* Haunt can ruin Enigma's initiation with Blink Dagger, no matter where he is on the map.
* Dispersion reflects the damage of Midnight Pulse and Black Hole inflicted back to Enigma.

* None of Spectre's spells are very good for Rubick to Spell Steal.

* 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.

* 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:
* Nethertoxin breaks 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.
* 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.

* 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.

* Nethertoxin prevents the lifesteal from Ransack. The silence from Viper's level 25 talent also prevents Meepo escaping with Poof.
* Meepo and his clones have a lack of magic resistance, so they're vulnerable to Poison Attack & Viper Strike directed onto one clone.

* 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.

* 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.