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

* Fate's Edict gives full immunity from Ogre Magi's mostly magical damage.
* Fortune's End can dispel Ignite (when used on allies) and Bloodlust (when used on enemies).
* False Promise can dispel Ignite and Fireblast.

* 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.

* Oracle can negate all of Techies' skills with Fate's Edict, as they are all magic damage. Fate's Edict can also be used to search and trigger Proximity Mines when crossing mined territory.
* Oracle can dispel Reactive Tazer off Techies, as well as the silence from Blast Off!, with Fortune's End.
* Oracle can further delay Techies' burst damage capability with False Promise.
Additional:
* Fate's Edict gives 100% magic resistance, which prevents most of Techies' damage.
* Oracle's Fortune's End dispels Reactive Tazer buff from Techies allowing him to be attacked. However, Reactive Tazer will instantly perform the area of effect disarm that is normally applied at the end of the duration.
* Fortune's End will also dispel Blast Off silence, Techies' Etheral Blade, Proximity Mines' magic resistance reduction, and Sticky Bomb's slow. However beware that it will only dispel Sticky Bomb's first or second instance of slow and not the damage, which will trigger as normal.

* 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.

* False Promise can dispel the stun from Cold Feet and can save an ally that's about to shatter from Ice Blast, even allowing healing with Purifying Flames by delaying it until after the debuff expires.
* Purifying Flames allows Oracle to deny his allies if they're affected by Ice Blast. If he brings his allies' health to or below the shatter threshold, it will count as him denying the ally. However, this does not work on Oracle himself.
* Fate's Edict provides 100% magic resistance, making it good against all of Ancient Apparition's abilities at all stages of the game.
* Fortune's End can dispel Cold Feet from allies.
Additional:
* False Promise can prevent the shatter from Ice Blast and Fate's Edict can protect an ally from the magical damage over time for a while.
* Oracle can deny allies who are frostbitten. If he uses Purifying Flames to reach the shatter threshold, it will count as a deny.
* Fortune's End can dispel Cold Feet on affected allies, preventing them from getting frozen.

* 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.

* During the laning stage, Oracle's Purifying Flames nullifies any damage that Heartstopper Aura might inflict.
* Fate's Edict and False Promise can protect an ally from Reaper's Scythe.
* Oracle can dispel Ghost Shroud with Fortune's End.
Additional:
* Fortune's End can dispel Ghost Shroud, negating the skill's utility. Also it's worth noting that Necrophos takes additional magic damage when in Ethereal state, which makes Purifying Flames a powerful nuke against him.
* Fate's Edict fully negates the damage from Reaper's Scythe, which its own delayed animation makes it relatively easy to predict and nullify.

* 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.

* Phoenix does significant magic damage over time which can either be dispelled or negated by Fate's Edict.
* Oracle's burst damage potential can prove lethal to Phoenix, as they already have to sacrifice health to cast their basic skills.

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

* Fortune's End can catch out or impair position-based heroes with low mobility, such as Sniper or Razor.

* 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 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.

* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.

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

* Heroes that can purge his slow and disables are very difficult to go on and their team: Abaddon, Oracle.

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

* Fate's Edict can disarm Troll, rendering him useless in a teamfight, especially if he has already used Battle Trance.
* Fortune's End and Purifying Flames can provide ample magic damage to help burst down Troll Warlord quickly in the early to mid game.
* False Promise can save an ally from Troll Warlord's initiation, forcing him to switch targets and lose his Fervor stacks, or waste time during Battle Trance.

* 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.

* Fortune's End and False Promise easily dispel many crippling debuffs, such as Venomancer's Venomous Gale, or Skywrath Mage's Ancient Seal.

Additional:
* Fortune's End can dispel Venomous Gale and Poison Sting from allies.
* Fate's Edict grants 100% magic resistance to target, inhibiting the damage from Venomancer abilities.

* 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.

* Oracle with Fortune's End and False Promise
* Heroes that can remove the Track debuff with their skills:
* Abaddon with Aphotic Shield and Borrowed Time
* Huskar with Life Break
* Juggernaut with Blade Fury
* Legion Commander with Press the Attack
* Lifestealer with Rage and Infest
* Naga Siren with Mirror Image
* Omniknight with Heavenly Grace
* Oracle with Fortune's End and False Promise
* Phantom Lancer with Doppelganger
* Slark with Dark Pact
* Ursa with Enrage
* Weaver with Time Lapse
* Tidehunter with Kraken Shell when damage received reaches the threshold.

* 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.

* Fortune's End can catch out or impair position-based heroes with low mobility, such as Sniper or Razor.

* Heroes who can harass Omniknight out of lane will keep him weak in the mid game: Viper, Venomancer, Clinkz.

* Fortune's End's AoE dispel will remove Heavenly Grace and Guardian Angel.
* Fate's Edict can give spell immunity for protection against Omniknight's abilities at the cost of being disarmed.
Additional:
* Oracle can dispel Heavenly Grace (which he can also bait out with Fate's Edict).
* With Fortune's End, Oracle can dispel Guardian Angel in an area of effect.

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

* Heroes with little health or magic resistance are easily picked off with Oracle's magic burst, such as Skywrath Mage, Crystal Maiden, or Enchantress.

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

* Fate's Edict cripples many heroes who rely on attacks, such as Phantom Assassin, Sven, or Enchantress, without a dispel or a Black King Bar.

* 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.

* Heroes with little health or magic resistance are easily picked off with Oracle's magic burst, such as Skywrath Mage, Crystal Maiden, or Enchantress.

* 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' 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.

* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: Sven, Omniknight, Enigma, Luna, Naga Siren, Mars, Jakiro, Venomancer, Elder Titan, Faceless Void, Rubick, Keeper of the Light, Pugna, Invoker, Spectre, Alchemist, Treant Protector, Lina, Oracle, Zeus, Shadow Shaman, Phoenix, Razor, Huskar, Batrider, Kunkka, Tidehunter, Wraith King, Sand King, Medusa, Dawnbreaker.

* 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.
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.

* 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.

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

* 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.

* Fortune's End dispells Marci's Sidekick, removing additional damage and lifesteal.
* Fate's Edict disarms Marci, preventing her from attacking with Unleash. Also it is useful against Marci or her ally affected by Sidekick.
* False Promise is a great tool to save an ally focused by Marci.

* 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.

* False Promise dispels Flaming Lasso.
* Fortune's End can root Batrider after he uses Flaming Lasso. It can also dispel Sticky Napalm and Flamebreak.
* Fate's Edict when used on a Lasso'd target will leave them immune to magical damage, making it difficult to burst them quickly before the Lasso ends.

* 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.

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

* Oracle can shut down both of Ember's early game abilities. Fortune's End can dispel Flame Guard on Ember Spirit and Searing Chains on allies.
* When Ember Spirit is affected by Fortune's End, his Fire Remnants move at 0 movement speed.
* Disarming him with Fate's Edict does affect Ember's Sleight of Fist ability, possibly making him useless for a few seconds in the late game without a dispel or spell immunity. This is especially good if he has a rapier or two. However, positioning for this is difficult when Ember plays far back.

* 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.

* 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.

* Oracle's Fate's Edict will protect an ally from Leshrac's nuking damage.
* Oracle's False Promise can dispel Leshrac's stun and slow from his abilities, allowing an ally to escape.
* Fortune's End can stop Leshrac from chasing opponents or running away.

* 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.

* Oracle can negate and shut down Primal Beast simply with Fate's Edict, especially in the early game, as a majority of his damage-dealing spells are magic.
* Oracle can interrupt Primal Beast's Onslaught charge with a well-timed Fortune's End.
* Primal Beast's lethal burst damage combos can be further stalled with False Promise; combined with Fate's Edict and regen from Purifying Flames, Oracle can even completely negate Primal Beast's offense.
Additional:
* Fate's Edict completely negates all of Primal Beast's major damage-dealing spells in the early game and can render Primal Beast useless when cast on a target he is focusing, or in Oracle's defense against Primal Beast himself.
* Fortune's End keeps Primal Beast in place, especially while trampling or in the middle of an Onslaught charge.
* False Promise can interrupt Primal Beast's Pulverize, as well as further delay Primal Beast from dealing lethal burst damage. In combination with Fortune's End, Oracle can potentially save an ally from Primal Beast's spell combos.

* Fate Edict can completely negate Skywrath Mage's heavy magic damage.
* Fortune End dispels Ancient Seal.

* Corrosive Skin minimizes the damage from Impale and Mana Burn.
* Nyx Assassin cannot survive several poison damage-over-time, even Spiked Carapace is activated.

* 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.

* Fortune's End applies a basic dispel which can be used to dispel Corrosive Haze, or even Slardar's own Guardian Sprint.
* False Promise is able to dispel Corrosive Haze and Slithereen Crush stun/slow from any allies Oracle chooses to cast it on.
* Fate's Edict can also be cast on Slardar to prevent him from proccing his Bash of the Deep.

* Nethertoxin disables Dawnbreaker's Luminosity|Dawnbreaker. 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.

* 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

* Fate's Edict allows Oracle to make allies spell immune, allowing him to save allies from Jakiro's spells.
* Fate's Edict can be cast onto Jakiro to disarm him and prevent him from pushing with his Liquid Fire.
* False Promise allows Oracle to free allies from Jakiro's Ice Path.

* 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.

* Fortune's End not being disjointable is almost an ensured disable if Dark Willow tries to escape with Shadow Realm. Dispels Cursed Crown and Terrorize.
* Fate's Edict negates all her magic damage in case she catches a single hero.
* False Promise's strong dispel removes Dark Willow's disables.
Additional:
* Fortune's End can easily dispel Cursed Crown before it times out and stuns. He can also save a stunned ally with False Promise.
* Fate's Edict can easily negate Bedlam's over-time damage, since the spell provides no form of control. Similarly, he can also negate the magic burst from Shadow Realm.
* Fortune's End can dispel the fear effect from Terrorize, and it can remove the root from Bramble Maze if cast quick enough. Be mindful that Fortune's End only dispels your allies' debuffs on the primary target.

* 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.

* 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.

* 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.

* 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.

* Heroes that can apply early pressure before Phantom Assassin has farm are massive threats: Axe, Viper, Meepo, Pugna, Slark etc.

* Fate's Edict cripples many heroes who rely on attacks, such as Phantom Assassin, Sven, or Enchantress, without a dispel or a Black King Bar.

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

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

* Heroes with abilities that can save teammates are also effective such as Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.

* Heroes with Break abilities will prevent Slark from regenerating and gaining Essence Shift stacks: Viper, Shadow Demon, etc.

Additional:
* 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).

* 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 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.

* Fortune's End can nullify Arcane Curse, Last Word, and Global Silence, if cast at the right time with the right targets.
* Fate's Edict can prevent Silencer from attacking, which he relies on with Glaives of Wisdom, for a lot of his damage.

* Heroes that can protect or dispel stunned allies such as Legion Commander, Outworld Destroyer, Shadow Demon and Oracle can reduce the effectiveness of Sacred Arrow.

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

* Nethertoxin prevents Timbersaw from gaining stacks on Reactive Armor.

* 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.

* False Promise effectively nullifies Primal Roar's single-target initiation on allies.
* Purifying Flames kills Beastmaster's Hawk instantly and Boar with two casts.

* Fortune's End dispels Ion Shell and Surge, making any gank attempt on Dark Seer in the laning phase likely to succeed.
* Fate's Edict prevents all magical damage that comes from Dark Seer's abilities.
* Fortune's End dispels Ion Shell on creeps, which Dark Seer relies on to farm and zone.
Additional:
* Fortune's End can dispel Ion Shell, a skill that helps Dark Seer immensely in the laning phase, as well as Surge, a move-speed buff, effectively allowing Oracle to control Dark Seer, especially in the laning phase.

* 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.

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

* Heroes with area dispel can kill multiple skeletons at once: Brewmaster, Oracle.

* 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 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.

* Oracle's high magic damage output can easily take down Rubick's low health pool.
* Because Oracle can combo spells in rapid succession (due to low cooldowns), it may be difficult for Rubick to Spell Steal False Promise. This scenario can even be avoided by shift queueing Fortune's End and casting it immediately, as it has no cast point, or by staying in the back line of fights if out of mana.
* As a position based hero, Rubick will have a very hard time against Fortune's End due to its absurd range and very long root duration.

* All of Pugna's damage is magical, which can get blocked by Fate's Edict's 100% magic resistance.
* Oracle has two abilities that apply a dispel, which can easily remove Decrepify on his ally or Oracle.

* It is especially easy for Oracle to negate the damage from Maledict, and even heal through it with Fate's Edict and Purifying Flames.
* If by some miracle an enemy is still about to die because of Maledict, he can still save him with False Promise.

* 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.

* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer

* 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.

* 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:
* 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.