Sven
* Heroes that deal few, powerful instances of damage, like 
Oracle, 
Lion, or 
Sven, have a hard time breaking through Gravekeeper's Cloak.
Nyx Assassin
* Even though Visage's Familiars from 
Summon Familiars are fragile and can be killed quickly with Nyx Assassin's high burst damage, they can deal many instances of damage quickly, minimizing the effectiveness of Spiked Carapace.
* 
Gravekeeper's Cloak and tanky item builds make Visage hard for Nyx to kill with his burst damage. 
Aghanim's Shard upgraded Gravekeeper's Cloak also allows Visage to use 
Stone Form to both recover himself and stun Nyx Assassin if he is close enough to Visage.
* Visage's long range on 
Soul Assumption and 
Grave Chill make him hard to escape from, and Soul Assumption's low cooldown outmatches Spiked Carapace.
Sven
* Heroes that can prevent Sven from farming are very strong against him. Such as 
Riki and 
Bounty Hunter with their respective invisibility.
Nyx Assassin
* Nyx Assassin wants to start ganking as soon as he gets his 
Vendetta. Keeping him Tracked prevents him from ganking, and thus from doing his job in the game.
* Nyx Assassin has a lot of armor and health regen, making the nuke damage from Shuriken Toss very good against him.
Additional:
* 
Track hinders Nyx Assassin's ganking and escaping attempts with Vendetta, making him an easy kill for gold as well.
* Bounty Hunter can also use Track on Nyx Assassin while he has 
Spiked Carapace active without getting stunned as Track deals no damage at all before using 
Shuriken Toss.
Sven
* Heroes who thrive on teamfights can be a problem, such as 
Venomancer, 
Necrophos, 
Centaur Warrunner...
Nyx Assassin
* Centaur's low Intelligence makes 
Mind Flare do low damage.
* With some creative skill builds, Centaur's Hoof Stomp stun duration should always last longer than Spiked Carapace stun, so escaping unscathed is hard for Nyx.
* With 
Blink Dagger and detection, Centaur can devastate Nyx in the open.
* However, bear in mind that Nyx can also easily initiate on Centaur Warrunner as well if he uses Spiked Carapace in anticipation, and with Vendetta. The damage from Retaliate will be reflected back to Centaur Warrunner, stunning him with no chance to react after he's revealed himself, and should guarantee a successful 
Impale.
Sven
* 
Whirling Axes (Melee)'s blind makes Sven nearly useless in the early game and allows Troll Warlord to take him on comfortably.
* 
Battle Trance will mean Sven will never take Troll out in a 1vs1 with equal farm.
Additional:
* Berserker's Rage together with Troll Warlord's high attack speed gives Troll a high chance of rooting enemies, which allows Troll Warlord to man-fight Sven.
* Whirling Axes (Melee) provides a 60% miss chance, and the passive armor provided by Berserker's Rage makes Troll resilient to physical damage in early game. Sven's 
God's Strength is much less effective as a result.
* Beware that Sven can farm much faster than Troll Warlord by stacking ancients and clearing them with 
Great Cleave.
Nyx Assassin
* Heroes who build 
Black King Bar as either core or situational item will be able to fight back against Nyx Assassin and freely attack him as Spiked Carapace cannot pierce spell immunity at all: 
Axe, 
Broodmother, 
Dawnbreaker, 
Enigma, 
Huskar, 
Jakiro, 
Legion Commander, 
Lina, 
Luna, 
Lycan, 
Slardar, 
Slark, 
Troll Warlord, 
Witch Doctor.
Sven
* Heroes that rely on physical damage are ineffective against Dragon Knight due to his high armor: 
Phantom Assassin,
Bloodseeker, 
Lifestealer, Troll Warlord, Sven
Nyx Assassin
* Dragon Knight's heavy armor negates Vendetta's burst physical damage. His large HP pool also gives him a good chance of surviving Nyx Assassin's follow-up nuke damage.
Sven
* Melee heroes with low mobility can be kited and killed by Viper: 
Treant Protector, 
Kunkka, 
Alchemist, Troll Warlord, 
Wraith King, 
Tiny, Sven.
Nyx Assassin
* 
Corrosive Skin minimizes the damage from Impale and Mind Flare, and anything else Nyx Assassin tries to throw at Viper.
* Nyx Assassin cannot survive several poison damage-over-time output from 
Poison Attack, 
Nethertoxin, Corrosive Skin and 
Viper Strike, not even while he has Spiked Carapace active. And to make things worse, Nyx Assassin is not a common 
Silver Edge wielder to counter this problem at all.
Additional:
* Corrosive Skin minimizes the damage from Impale and Mind Flare, and anything else Nyx Assassin tries to throw at Viper.
* Nyx Assassin cannot survive several poison damage-over-time output from Poison Attack, Nethertoxin, Corrosive Skin and Viper Strike, not even while he has Spiked Carapace active. And to make things worse, Nyx Assassin is not a common Silver Edge wielder to counter this problem at all.
Sven
* Heroes who thrive on teamfights can be a problem, such as Venomancer, Necrophos, Centaur Warrunner...
Nyx Assassin
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, 
Viper, Venomancer, Huskar, 
Ember Spirit, 
Dark Seer, 
Sand King, 
Doom, Dawnbreaker. However, this also means they are easily stunned.
Sven
* 
Cold Embrace saves any ally Sven initiates on and wastes the duration of God's Strength in team fights.
* 
Winter's Curse can be devastating to Sven's team, as his massive damage can take out a teammate before there is much time to react.
Nyx Assassin
* 
Rage allows Lifestealer to freely attack Nyx Assassin and hunt him down if Vendetta is on cooldown. Nyx Assassin cannot counter Rage with Spiked Carapace because Rage gives Lifestealer spell immunity. And besides Vendetta, Nyx Assassin has no other way of dealing damage to Lifestealer while he is spell immune.
* 
Open Wounds from Aghanim's Shard allows Lifestealer to severely slow down Nyx Assassin while also allowing his team to recover themselves while attacking Nyx Assassin. Open Wounds can also fester and spread if Nyx Assassin takes enough damage that will trigger the spread while he is affected with Open Wounds.
* 
Infest combined with an ancient creep makes Nyx Assassin an easy target to surprise with 
Dust of Appearance or a 
Gem of True Sight. 
Aghanim's Scepter upgraded Infest can also allow Lifestealer to infest, disarm and freely attack Nyx Assassin from within. and Nyx Assassin cannot counter this with Spiked Carapace because Lifestealer is invulnerable while attacking the infested enemy hero from within.
* Overall, any attempt for Nyx Assassin to gank and kill Lifestealer will hurt Nyx Assassin more than Lifestealer.
Additional:
* Like with Juggernaut's 
Blade Fury, Rage allows Lifestealer to freely attack Nyx Assassin and hunt him down if Vendetta is on cooldown. Nyx Assassin cannot counter Rage with Spiked Carapace because Rage gives Lifestealer spell immunity. And besides Vendetta, Nyx Assassin has no other way of dealing damage to Lifestealer while he is spell immune.
* Open Wounds from Aghanim's Shard allows Lifestealer to severely slow down Nyx Assassin while also allowing his team to recover themselves while attacking Nyx Assassin. Open Wounds can also fester and spread if Nyx Assassin takes enough damage that will trigger the spread while he is affected with Open Wounds.
* Infest combined with an ancient creep makes Nyx Assassin an easy target to surprise with Dust of Appearance or a Gem of True Sight. And similarly to Juggernaut's 
Omnislash and 
Swiftslash from Aghanim's Scepter, Aghanim's Scepter upgraded Infest can also allow Lifestealer to infest, disarm and freely attack Nyx Assassin from within. And Nyx Assassin cannot counter this with Spiked Carapace because Lifestealer is invulnerable while attacking the infested enemy hero from within.
* Like with Juggernaut, any attempt for Nyx Assassin to gank and kill Lifestealer will hurt Nyx Assassin more than Lifestealer.
Sven
* Sven has no easy way to burn 
Refraction charges and needs help from teammates to kill TA successfully.
Sven
* Undying can use Decay not only to reduce Sven's maximum health, but also to reduce the damage he can deal with his ultimate.
* Zombies spawned by Tombstone together with Flesh Golem slow Sven down significantly. Landing Sven's powerful but somewhat slow right-click on Tombstone would be a waste.
Nyx Assassin
* 
Corrosive Haze hinders Nyx Assassin's ganking attempts with Vendetta, as well as reducing his armor and make him very vulnerable due to his low health pool.
* 
Guardian Sprint allows Slardar to catch up with Nyx Asssassin and finish him off if he has vision over him.
Sven
* Multicast Fireblasts over the course of fights are a decent nuisance to stall Sven's massive damage output.
* Bloodlust and Ignite gives Ogre Magi's team the movement speed difference needed to chase and/or disengage against a Sven and his 
Warcry.
* Ignite provides strong damage over time to pressure Sven early on in the laning phase and keep his health low, delaying his transition into the jungle. Ignite is also an easy way to disrupt Blink Dagger, Sven's most popular way of initiation.
* Ogre Magi's presence in the laning phase both in terms of damage and durability keeps high pressure on Sven in lane.
* Purchasing an Aghanim's Shard allows Ogre Magi to greatly reduce the burst damage of Sven, who tends to build items focused on damage per hit instead of attack speed.
Sven
* 
Cloak and Dagger makes Sven unable to detect where Riki is until he shows or his team provides detection.
* 
Smoke Screen will make Sven miss attacks before he has his Black King Bar.
Nyx Assassin
* 
Cyclone from Storm in 
Primal Split can waste Nyx's Spiked Carapace, since its duration is shorter than the Cyclone's.
Sven
* Primal Roar takes Sven out of the fight completely, even with Black King Bar.
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.
Sven
* Heroes who can take advantage of God's Strength being on cooldown are also not great matchups, such as 
Templar Assassin, 
Morphling and Huskar.
Nyx Assassin
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, Viper, Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom, Dawnbreaker. However, this also means they are easily stunned.
Nyx Assassin
* 
Nyx Assassin can reflect Life Break with Spiked Carapace.
Sven
* Heroes who can stun Sven even with an activated Black King Bar can be an issue: 
Clockwerk, 
Beastmaster.
Sven
* Heroes who can take advantage of God's Strength being on cooldown are also not great matchups, such as Templar Assassin, Morphling and Huskar.
Sven
* Heroes who can fight back easily are not ideal matchups for Sven, such as Troll Warlord as mentioned above, 
Lone Druid and Templar Assassin.
Nyx Assassin
* Heroes with invisibility will be detected by Thirst when they have low enough health: Bounty Hunter, Templar Assassin, Riki, 
Clinkz, 
Weaver, Treant Protector, Nyx Assassin.
Additional:
* While Burrowing, Nyx is an easy target for a 
Blood Rite, and his only way to counter it is a well-timed Spiked Carapace.
* 
Thirst is always a threat to Nyx Assassin, hindering his attempt of escape using Vendetta and rendering him unable to surprise Bloodseeker's allies.
* 
Rupture also prevents Nyx Assassin from escaping with Vendetta, as it forces him to stay still.
Sven
* Sven is very vulnerable to chain stun such as Lion, 
Shadow Shaman or 
Magnus.
Nyx Assassin
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, Viper, Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom, Dawnbreaker. However, this also means they are easily stunned.
Nyx Assassin
* Heroes who build Black King Bar as either core or situational item will be able to fight back against Nyx Assassin and freely attack him as Spiked Carapace cannot pierce spell immunity at all: Axe, Broodmother, Dawnbreaker, Enigma, Huskar, Jakiro, Legion Commander, Lina, Luna, Lycan, Slardar, Slark, Troll Warlord, Witch Doctor.
Sven
* Heroes that relies on armor or other type of physical damage negation are easy for Gyrocopter to take down during the early game with his magical damage: Axe, 
Dragon Knight, Sven.
Nyx Assassin
* Heroes who rely on invisibility, such as Bounty Hunter, Clinkz, 
Mirana, Nyx Assassin and Riki, as they will be revealed if caught by Chronosphere.
Sven
* Heroes that lose a great amount of damage output and become less threatening: Phantom Assassin, Sven, Slark, 
Phantom Lancer.
* Once you have an Aghanim's Scepter, Shadow Demon instantly reaches a new power spike and becomes a counter for a variety of heroes that have strong passives.
* Heroes that lose a great amount of their tankiness and become easier to finish off: 
Bristleback, 
Spectre, Phantom Assassin, Enchantress, Dragon Knight.
* Heroes that lose a great amount of damage output and become less threatening: Phantom Assassin, Sven, Slark, Phantom Lancer.
* You can always stack camps and farm the scepter with Shadow Poison.
Nyx Assassin
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, Viper, Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom, Dawnbreaker. However, this also means they are easily stunned.
Sven
* Heroes that rely on right-clicks will find themselves unable to damage opponents seriously after being affected by Static Link, like Sven, Bloodseeker, and 
Juggernaut.
Additional:
* 
Static Link saps Sven's insane attack damage, and goes through Black King Bar.
Nyx Assassin
* Some abilities deals damage from an independent source and not from the hero itself, so Nyx cannot counter them with Spiked Carapace: illusions or summoning units, 
Homing Missile, 
Nimbus, 
Mass Serpent Ward, 
Death Ward and especially 
Techies's mines.
Nyx Assassin
* Blade Fury makes Juggernaut immune to all Nyx's abilities, except Vendetta.
* Omnislash. and Swiftslash can burst Nyx down, ignoring Spiked Carapace. However, Vendetta can be used to escape, canceling Omnislash/Swiftslash.
Additional:
* Juggernaut's entire skillset greatly counters Nyx Assassin's Spiked Carapace, his most important ability.
* Blade Fury allows Juggernaut to freely attack Nyx Assassin, and deal heavy damage to Nyx Assassin. Nyx Assassin cannot counter Blade Fury with Spiked Carapace because Blade Fury gives Juggernaut spell immunity. And besides Vendetta, Nyx Assassin has no other way of dealing damage to Juggernaut while he is spell immune.
* 
Healing Ward allows Juggernaut to recover himself and his allies from Nyx Assassin's damage output.
* Omnislash and Swiftslash from Aghanim's Scepter can quickly finish off Nyx Assassin. And just like Blade Fury, Nyx Assassin cannot counter neither Omnislash and Swiftslash from Aghanim's Scepter with Spiked Carapace because both abilities render Juggernaut invulnerable. And if Nyx Assassin has no Vendetta available to use for escaping, both abilities will kill him very quickly before he can do anything.
* Overall, any attempt for Nyx Assassin to gank and kill Juggernaut will hurt Nyx Assassin more than Juggernaut.
Sven
* Heroes with high armor and/or durability can handle Juggernaut's ultimate, such as Sven and Dragon Knight.
Additional:
* Warcry allows Sven to tank the damage from Omnislash due to its high armor gain.
* However Blade Fury provides spell immunity which blocks the stun from 
Storm Hammer.
Nyx Assassin
* Impale and Spiked Carapace stun can be instantly dispelled by Aphotic Shield.
* Abaddon can use Borrowed Time and easily heal for the duration of Borrowed Time by Nyx's burst damage.
Nyx Assassin
* Nyx Assassin might not kill Abaddon with his nuke, but a support Abaddon will struggle to protect an ally from him.
Nyx Assassin
* Even though Nyx Assassin can easily kill Luna with his high burst damage, Luna can also do the same to him if he is not careful.
* 
Lucent Beam can deal a fair amount of damage to Nyx Assassin if he has no Spiked Carapace available to use. Although Luna should be patient using Lucent Beam on Nyx Assassin when he uses Spiked Carapace.
* As Luna commonly buys Black King Bar, she can use it to freely attack Nyx Assassin whenever he tries to defend himself with Spiked Carapace during teamfights. Luna can also buy 
Eye of Skadi and 
Manta Style to survive Nyx Assassin's burst damage and distract him.
* Though Vendetta can deal serious damage to Luna and avoid 
Eclipse, smart Luna will always buy Dust of Appearance to provide vision on Nyx Assassin to her and her team.
Additional:
* Even though Nyx Assassin can easily kill Luna with his high burst damage, Luna can also do the same to him if he is not careful.
* Lucent Beam can deal a fair amount of damage to Nyx Assassin if he has no Spiked Carapace available to use. Although Luna should be patient using Lucent Beam on Nyx Assassin when he uses Spiked Carapace.
* As Luna commonly buys Black King Bar, she can use it to freely attack Nyx Assassin whenever he tries to defend himself with Spiked Carapace during teamfights. Luna can also buy Eye of Skadi and Manta Style to survive Nyx Assassin's burst damage and distract him.
* Though Vendetta can deal serious damage to Luna and avoid Eclipse, smart Luna will always buy Dust of Appearance to provide vision on Nyx Assassin to her and her team.
Sven
* A couple of nukers and disablers on the same lane can finish a squishy Luna efficiently despite a teammate's assistance: Sven + Shadow Shaman.
Sven
* Storm Hammer stunned can stops Snapfire's 
Mortimer Kisses.
Nyx Assassin
* Spiked Carapace stops Snapfire's Mortimer Kisses.
Sven
* Great Cleave with God's Strength clears Terrorblade's illusions quickly.
* Storm Hammer's AoE stuns Terrorblade and his illusions.
* Warcry gives Sven and his allies armor to withstand Terrorblade's only-physical damage output.
Nyx Assassin
* Nyx Assassin deals large amounts of pure damage with Vendetta and magical damage with Impale and Mind Flare, allowing him to ignore Terrorblade's armor and burst his low health pool down before he can use 
Sunder.
* Nyx Assassin commonly buys 
Urn of Shadows, 
Dagon and 
Meteor Hammer which deal magic damage that ignore Terrorblade's armor.
* However, Terrorblade is a natural Eye of Skadi and Black King Bar wielder, and once he gets those items, Nyx Assassin's solo kill potential against Terrorblade will be gone.
Sven
* With God's Strength, Warlock's Golem from 
Chaotic Offering will go down in a matter of seconds. The two weaker golems granted by Aghanim's Scepter will fare worse due to Great Cleave hitting both.
* Aghanim's Scepter upgraded Storm Hammer Aghanim's Scepter can dispel 
Shadow Word.
Additional:
* God's Strength combined with Great Cleave destroys Chaotic Offering golems within seconds.
* Warcry gives Sven and his allies armor to help against Warlock's Golem's heavy physical damage and movement speed to help escape Upheaval.
* Storm Hammer disrupts Upheaval.
Nyx Assassin
* Impale and Spiked Carapace interrupts Upheaval with ease.
* Warlock's low health pool, mobility, and high intelligence gain makes him a prime target for Nyx Assassin's burst damage.
Sven
* Storm Hammer locks down Chen and his converted creeps.
* Great Cleave and God's Strength can destroy Chen and his creeps quickly.
* Warcry minimizes damage taken from creeps's attacks.
Additional:
* Great Cleave can quickly destroy Chen's creeps in team fights, before they have a chance to do much.
Nyx Assassin
* Heroes with either magical, physical or pure damage burst can often kill Chen or his allies before he can use Hand of God: Lina, Luna, Techies, 
Shadow Fiend, 
Pugna, Nyx Assassin.
Sven
* Heroes who cannot prevent Sven from killing towers will often struggle from a small map very early, such as Phantom Assassin, 
Storm Spirit and Phantom Lancer.
Nyx Assassin
* Mana Burn removes much-needed mana for 
Ball Lightning.
* Spiked Carapace triggers on 
Static Remnant for an easy stun.
Additional:
* Vendetta is capable of removing most of Storm Spirit's large mana pool, along with dealing heavy damage and quickly depleting his chances of escaping a gank or fight.
Sven
* Fragile supports who die in a few hits against Sven's high physical damage: 
Crystal Maiden, 
Vengeful Spirit, 
Dark Willow.
Nyx Assassin
* Crystal Maiden has a very bad movement speed, so Impale is easy to land against her. Furthermore, even while trapped by Frostbite, Nyx Assassin can still cast Impale.
* Crystal Maiden has very low armor, so Vendetta is very effective.
* Nyx Assassin has two ways to stop Freezing Field, provided she doesn't get a Black King Bar. He can either pop Spiked Carapace and simply walk into the field, or he can use Impale to interrupt the field, since Crystal Maiden has to channel it.
Additional:
* Spiked Carapace easily interrupts 
Freezing Field.
* 
Frostbite's damage over time sets up an easy Spiked Carapace stun.
* Crystal Maiden is extremely fragile and dies quickly to Nyx Assassin's burst damage.
Sven
* Generally heroes who don't rely on magical damage, such as Sven, Phantom Assassin, and 
Outworld Destroyer, as they can practically ignore Flesh Heap's damage block.
Nyx Assassin
* Impale and Spiked Carapace can be used to cancel Dismember easily, and can even do so when Pudge uses it on Nyx Assassin, if timed correctly.
Sven
* Heroes with high burst damage and Black King Bar can take down Dark Willow quickly: Phantom Assassin, Sven, Wraith King
Nyx Assassin
* Nyx Assassin's high burst damage can be the bane of Dark Willow, as her low health makes it difficult to survive long enough to escape through Shadow Realm.
* Spiked Carapace can be triggered by walking deliberately into Bramble Maze, leaving Dark Willow stunned and defenseless.
Nyx Assassin
* Heroes who build Black King Bar as either core or situational item will be able to fight back against Nyx Assassin and freely attack him as Spiked Carapace cannot pierce spell immunity at all: Axe, Broodmother, Dawnbreaker, Enigma, Huskar, Jakiro, Legion Commander, Lina, Luna, Lycan, Slardar, Slark, Troll Warlord, Witch Doctor.
Sven
* Sven has a high health pool and is a natural Black King Bar holder and is very hard to kill for Lina.
* Sven also has high physical damage, making it easy for him to burst her down.
Nyx Assassin
* Mind Flare does tons of damage against Lina because of her high intelligence.
* Vendetta can deal heavy damage to Lina while also burning her mana, preventing Lina from casting her abilities.
* Spiked Carapace can easily be used to counter Lina's abilities because of their long cast animation, and could probably kill Lina outright if Laguna Blade is reflected. However, Lina can counter this with 
Eul's Scepter of Divinity, a common item on Lina.
Sven
* Other heroes that rely on physical attacks to deal damage and not their abilities: Troll Warlord, 
Sniper, 
Monkey King, Sven.
Sven
* Sven with Aghanim's Scepter-upgraded Storm Hammer can easily chase down Windranger and dispel her Windrun at the same time.
Nyx Assassin
* 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.
Sven
* Special mention to Sven as he may not be able to get close, but if he does, God's Strength will make very short work of Sniper.
Sven
* Past the early game, Sniper is an easy target for Sven to jump on with Aghanim's Scepter upgraded Storm Hammer, Blink Dagger, Silver Edge or 
Harpoon, common items on Sven.
* Sven's high armor and health pool makes it difficult for Sniper to focus, as his main source of damage is his right click, especially if Sven uses Warcry.
* Sniper is very squishy, and will not stand a chance against Sven head on.
Nyx Assassin
* 
Assassinate is easy to reflect with Spiked Carapace for massive damage.
* 
Shrapnel's area damage can set up an easy stun with Spiked Carapace, especially when combined with Vendetta.
* In the early game, Sniper's low health pool and high intelligence makes him easy prey for Nyx Assassin.
Sven
* Heroes who cannot prevent Sven from killing towers will often struggle from a small map very early, such as Phantom Assassin, Storm Spirit and Phantom Lancer.
Nyx Assassin
* Heroes with heavy early and mid-game magical damage are also problematic for Phantom Assassin due to being able to easily kill her before she can gain an item advantage over them: Lina, Necrophos, Nyx Assassin, 
Gyrocopter, Jakiro, 
Death Prophet.
Sven
* Late game heroes are Sven's favourite kind of opponent, such as 
Anti-Mage, Spectre and Shadow Fiend.
Nyx Assassin
* Large area-of-effect with delay or require channeling: Enigma, Crystal Maiden, 
Invoker, Shadow Fiend, Pugna, 
Keeper of the Light, Dawnbreaker.
Sven
* 
Avalanche and 
Toss will never be enough damage to take out Sven in a clean way.
* Tiny is very slow with low armour growth and does not buy items to sustain Sven's damage output.
Nyx Assassin
* Nyx's Spiked Carapace can reflect the damage of 
Sharpshooter, instantly killing hoodwink. Nyx can also use Vendetta to position himself in such a way to screen allies from Sharpshooter and catch Hoodwink by surprise.
Sven
* Storm Hammer's faster projectile speed and cast time allows Sven to stun Chaos Knight and his illusions before he can cast Chaos Bolt.
* Warcry's armor bonus counteracts Reality Rift's debuff and reduces Chaos Knight's damage output.
* Great Cleave and God's Strength devastates Phantasm illusions.
Additional:
* Great Cleave is very effective against Chaos Knight's illusions.
* Storm Hammer's radius can catch all of Chaos Knight's illusions at once, especially after 
Reality Rift.
* Warcry shields Sven and his teammates against Chaos Knight's physical damage output.
Nyx Assassin
* A good Nyx can reflect Queen of Pain's Sonic Wave with his Spiked Carapace, or even initiate a gank on her in Vendetta while she farms a creep wave with Scream of Pain.
* Her strength to intelligence ratio is bad enough that he should be able to kill her without even requiring a Dagon, provided he can get his full combo off.
Sven
* God's Strength allows Sven to take down Death Prophet quickly, reducing the damage dealt over time from 
Exorcism.
* Warcry's bonus armor and movement speed is very useful for Sven and his teammates against Exorcism, which deals physical damage.
Nyx Assassin
* Nyx Assassin's Spiked Carapace will stun Leshrac when hit by any of his AOE abilities.
* Mind Flare deals high damage due to Leshrac's high intelligence gain.
* Vendetta burns a large amount of Leshrac's essential mana pool.
Nyx Assassin
* Nyx Assassin has a lot of burst damage from his Impale, Mind Flare, Dagon, and the bonus damage from Vendetta. All of this damage is enough to kill Drow Ranger.
* Nyx Assassin is usually invisible most of the time thanks to his ability Vendetta, which allows him to gank Drow Ranger easily.
* However, 
Gust is extremely dangerous for Nyx Assassin, as it's silence can render Nyx Assassin unable to lock down Drow Ranger. And if Gust hits Nyx Assassin while he is invisible with Vendetta, Drow Ranger will be able to detect him and foil his ganking attempts on her because Gust reveals invisible units.
Nyx Assassin
* Spiked Carapace reacts on any of the damage over time from Phoenix's abilities and can interrupt 
Sun Ray and 
Icarus Dive.
Nyx Assassin
* Ravage's travel time allows Nyx Assassin to easily stun Tidehunter with Spiked Carapace.
* Vendetta can instantly deplete Tidehunter's low mana pool, especially in the early game, potentially preventing Tidehunter from casting Ravage.
Nyx Assassin
* 
Last Word is extremely easy to reflect with Spiked Carapace for large amounts damage, due to triggering when Nyx Assassin casts a spell, but can still silence Nyx Assassin. It also has the added bonus of dealing more damage the more Intelligence Silencer has.
* 
Glaives of Wisdom quickly builds Silencer's Intelligence, making him a particularly prime target for Mana Burn.
* Silencer rarely builds survivability items, nor is he able to steal much Intelligence while surrounded by his team, and so is an excellent target for Vendetta.
* Silencer has no reliable way of dealing with a burrowed Nyx, and also lacks the ability to prevent Nyx from escaping with Vendetta,
Additional:
* Silencer is rather squishy and has poor mobility without items, making him an easy target for Nyx.
* Silencer's intelligence steal ability is a complete disadvantage against Nyx Assassin as Mind Flare will deal increasing damage for each point of intelligence Silencer has stolen, turning Silencer's intelligence steal against him.
Nyx Assassin
* 
Heat-Seeking Missile allow easy Spiked Carapace stuns.
* As a fragile hero that relies on mana and intelligence items, Tinker is vulnerable to Mana Burn.
* Nyx Assassin's stuns can interrupt 
Rearm and leave Tinker helpless.
Additional:
* Nyx Assassin's whole skillset is good against Tinker:
* Impale prevents Tinker from blinding Nyx Assassin or fighting back, while giving Nyx' allies time to catch up to Tinker's position.
* Mind Flare generally deals more damage to intelligence based heroes like Tinker.
* Spiked Carapace can stun Tinker at a moment of Nyx Assassin's choosing if March of the Machines has been cast. It is also quite easy to time Spiked Carapace against Heat Seeking Missiles.
* Vendetta allows Nyx to approach Tinker in the trees or wait for him in common hiding spots and deal heavy damage to his low armor.
Sven
* With the exception of Magic Missile (unless the player takes the Level 25 Talent "Magic Missile Pierces Spell Immunity"), all of Vengeful Spirit's spells ignore Spell Immunity. This also makes her good against heroes with built-in Spell Immunity like Lifestealer or Juggernaut or heroes that tend to pick up Black King Bar, like Sven.
Sven
* Fragile supports who die in a few hits against Sven's high physical damage: Crystal Maiden, Vengeful Spirit, Dark Willow.
Nyx Assassin
* Vendetta disables Vengeance Aura and allows him to attack Vengeful Spirit with Impale and Mind Flare.
* Spiked Carapace is easy to use against a Wave of Terror or Magic Missile.
Sven
* Storm Hammer interrupts Echo Stomp.
Sven
* Great Cleave and God's Strength can take down Meepo and his clones very quickly.
* The lack of spell immunity for Meepo's clones makes them vulnerable to Storm Hammer.
Additional:
* Great Cleave will devastate Meepo's clones. Against a closely packed group, Sven does not even need to target the clone with the lowest health.
Sven
* Sprout is good for trapping melee carries with no escape abilities: Sven, Alchemist, Lifestealer etc.
Sven
* Heroes with cleave damage: Sven, Magnus, Kunkka.
Nyx Assassin
* Heroes with invisibility: (Riki, Clinkz, Nyx Assassin.
Sven
* Side lanes with disables will greatly reduce the likeliness Void Spirit will be willing to rotate: Sven, Tiny, Wraith King, 
Ogre Magi.
Sven
* Heroes who cannot prevent Sven from killing supports will always be at a disadvantage in fights such as Lina, Slark and 
Zeus.
Nyx Assassin
* Slow-moving projectiles: 
Skywrath Mage, 
Tinker, Necrophos
Additional:
* Skywrath Mage's low health makes him rather easy prey for Nyx Assassin and his lack of armor generally means he'll take the full brunt of a Vendetta strike.
* Mind Flare turns Skywrath Mage's high intelligence growth against him and deals heavy damage.
* Spiked Carapace gives Nyx some degree of protection against Skywrath's spells.
Sven
* Heroes who struggle to fight back against Sven at any point in the game are at a severe disadvantage: Alchemist, Anti-Mage, Crystal Maiden.
Sven
* Melee carries who usually buy an early Black King Bar, and have gap closing abilities can be good against the Arc Warden, such as Slark, Riki, 
Earthshaker with Aghanim's Scepter, Sven with Aghanim's Scepter etc.
Sven
* Late game heroes are Sven's favourite kind of opponent, such as Anti-Mage, Spectre and Shadow Fiend.
Sven
* 
Purification can heal allies while dealing pure damage to Sven.
* 
Heavenly Grace can remove Storm Hammer's debuff immediately or make it a very mediocre stun.
* 
Guardian Angel negates Sven's massive damage during God's Strength.
* It should also be noted Sven can remove Omniknight's active spells with Aghanim's Scepter.
Sven
* Although Sven relies often on physical damage, an Aghanim's Scepter upgraded Storm Hammer can dispel Guardian Angel with its wide radius.
Nyx Assassin
* Heroes who can drain mana can make Omniknight useless after he uses one or two abilities: Lion, Anti-Mage, Nyx Assassin.
Nyx Assassin
* Heroes with either magical, physical or pure damage burst: 
Bane, Ember Spirit, 
Leshrac, Lina, Luna, Nyx Assassin, Phantom Assassin, Skywrath Mage, Tinker, 
Ursa, 
Void Spirit.
Nyx Assassin
* Heroes that can pick you off: Clinkz, Nyx Assassin, 
Puck, Riki.
Nyx Assassin
* Heroes with silence and mana drain abilites, as Ancient Apparition relies entirely on his abilities: Invoker, 
Silencer, Nyx Assassin, Skywrath Mage, Shadow Shaman, Lion and etc.
Nyx Assassin
* Nyx Assassin's skillset is mostly single-targeted, therefore he will have difficulties against heroes with illusions and summons: 
Naga Siren, Broodmother, Lycan, 
Visage, Phantom Lancer. And to make things worse, Nyx Asassin is not a common 
Battle Fury, 
Maelstrom, 
Mjollnir, 
Gleipnir or 
Radiance wielder to counter this problem.
Sven
* Great Cleave and God's Strength destroys illusions in just a few hits.
* Storm Hammer's AoE stun will hit Phantom Lancer when he's grouped up with illusions.
* Sven's low mana causes him to take less damage from 
Diffusal Blade. This is further reduced by the armor bonus from Warcry.
Additional:
* Great Cleave and God's Strength cuts through Phantom Lancer's illusions in no time.
* Storm Hammer's AoE stun will hit Phantom Lancer and his illusions.
Sven
* Batrider often hides in the trees to initiate on a target. As such, he has a slight edge against heroes that have no scouting tools and cannot see him coming, such as Lion or Sven.
Nyx Assassin
* Nyx can walk into Firefly with Spiked Carapace and stun Batrider if he has no Spell Immunity, even if Batrider is focusing on other enemy hero.
Sven
* Heroes who rely on burst physical damage are affected by Lucky Shot's disarm: 
Terrorblade, Sven, Clinkz, 
Windranger, Alchemist, Dragon Knight, Legion Commander
Sven
* Warcry can protect Sven and his teammates from 
Swashbuckle.
* With Black King Bar, Sven will be able to protect himself from most of Pangolier's skills.
Nyx Assassin
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, Viper, Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom, Dawnbreaker. However, this also means they are easily stunned.
Nyx Assassin
* With Vendetta, Nyx Assassin can move closely to Ember Spirit when he's farming with his Flame Guard and use Spiked Carapace with Impale to provide a reliable and long disable.
Additional:
* Spiked Carapace can be easily triggered by 
Flame Guard or Battle Fury, setting up a deadly Impale.
Sven
* Melee carries during the laning phase: Sven, Slark
Nyx Assassin
* Spiked Carapace can be used to reflect Illuminate damage and stun Keeper of the Light.
* Vendetta allows Nyx Assassin to follow Keeper of the Light around if he tries to split-push.
* Keeper of the Light is very squishy and will very quickly die to Vendetta and it's followup abilities.
Nyx Assassin
* Heroes that have a weak laning stage: Spectre, Nyx Assassin, Clockwerk, 
Spirit Breaker, 
Omniknight, 
Pudge.
Sven
* Warcry makes it difficult to burst Sven down with both the passive (with Aghanim's Shard) and active component.
* Sven under the effect of God's Strength and his massive physical damage make Sven very dangerous to engage in the mid game.
Sven
* Melee heroes that get kited easily have hard times dealing with Puck without any lockdowns, as Puck is one of the most mobile heroes. Heroes like Sven, Lifestealer, Ursa and Alchemist may have problems to get to Puck without proper initiation items. They also lack reliable lockdowns, as their disables are easily avoidable for Puck, or are just a soft disable.
Nyx Assassin
* 
Illusory Orb is easy to reflect with Spiked Carapace, either stunning Puck and setting up an easy Impale or forcing a premature 
Phase Shift.
* Puck is an intelligence hero that tends to build intelligence items, making it vulnerable to Mana Burn.
* An ill-timed Phase Shift can easily set Puck up to be stunned by Impale.
* Puck's low base armor and below average agility gain mean it is always susceptible to Vendetta.
Additional:
* Nyx Assassin can take advantage of every one of Puck's weaknesses. His entire skill set is very effective in countering Puck.
* Because Illusory Orb is such a slow moving projectile, Nyx Assassin can simply walk into the orb and activate Spiked Carapace, stunning Puck and setting up an easy Impale. This can be circumvented by using Phase Shift while the orb is traveling, however, that means that Puck cannot use Phase Shift to dodge any other skill nor use it to safely blink away from a fight.
* Puck is an intelligence hero that likes to build intelligence items such as Eul's Scepter of Divinity, 
Scythe of Vyse, and Dagon. This makes Mind Flare that much more deadly against Puck.
* An ill-timed Phase Shift can turn into an easy setup for Impale.
Nyx Assassin
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, Viper, Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom, Dawnbreaker. However, this also means they are easily stunned.
Nyx Assassin
* Spiked Carapace can stop Dawnbreaker's Solar Guardian which will eliminate her global presence and limits her movement around the map.
Additional:
* Spiked Carapace interrupts 
Starbreaker before Dawnbreaker has her Aghanim's Shard, as well as 
Solar Guardian during the initial channel, making her ineffective at joining and dealing damage in teamfights.
* The slow projectile and damage over time effect of 
Celestial Hammer makes it easy to stun Dawnbreaker if she attemps to engage or chase.
Sven
* Heroes with naturally low mana can be easily shut down by E.M.P.: Sven, Tiny, Wraith King, Omniknight
Nyx Assassin
* Nyx Assassin can simply activate Spiked Carapace while under many Invoker's abilities to stun him.
* Nyx Assassin takes advantage of Invoker's massive intelligence gain to do tons of damage using Mind Flare, as the spell does more damage based on the target's intelligence.
* Vendetta burns a large amount of Invoker's essential mana pool.
Nyx Assassin
* With Aghanim's Scepter, Broodmother will gain access to 
Spinner's Snare, which will allow her to create invisible lines on her webs from 
Spin Web that will root, deal damage over time, and reveal enemy heroes if they unwittingly step on them. This allows Broodmother to keep her allies alerted on heroes who rely on invisibility-themed and movement-themed abilities and items to surprise enemy heroes and disrupt ganking attempts of enemy heroes: Phantom Assassin, Nyx Assassin, Mirana, Bounty Hunter, Templar Assassin, Riki, Spirit Breaker, Anti-Mage, 
Tusk, Ursa, 
Nature's Prophet, Enigma, Void Spirit, Magnus etc.
Sven
* Great Cleave cleans up Spiderlings quicker than most spells, as it ignores their magic resistance.
* Sven is a natural Black King Bar carrier, protecting him from Silken Bola, Spawn Spiderlings and 
Orchid Malevolence.
* Warcry and God's Strength allow Sven to easily out-damage Broodmother.
Additional:
* Great Cleave can clear Spiderlings very quickly, and give Sven lot of gold.
* Warcry shields Sven and his allies against Broodmother and her Spiderlings.
Sven
* Tanky melee heroes that can easily be kited, which allows Outworld Destroyer to deal heavy damage with Arcane Orb from a distance: Sven, 
Underlord, Bristleback.
Nyx Assassin
* Outworld Destroyer's high intelligence gain and fragility makes him an easy target for a massive Mana Burn, as well as killing him outwards with Nyx Assassin's high burst damage.
* 
Astral Imprisonment can be easily exploited by Nyx Assassin with his abilities. As long as Astral Imprisonment was not cast on Nyx Assassin, it will make an opportunity for an easy stun, either by Spiked Carapace (if Outworld Destroyer hid his allies or your allies) or Impale (if he hid himself). If Astral Imprisonment was cast on Nyx Assassin, using Spiked Carapace while banished will proc the stun after the disable, since Spike Carapace has a 0 second cast time and Astral Imprisonment deals damage right after the disable ends.
* An ill-timed 
Sanity's Eclipse and/or well timed Spiked Carapace can deal a lot of damage to Outworld Destroyer and stun him, unless Outworld Destroyer used Black King Bar beforehand.
Additional:
* Outworld Destroyer's high intelligence makes him a good target for Mind Flare.
* If timed correctly, Spiked Carapace will return the full damage from Sanity's Eclipse back to Outworld Destroyer. Even a reflected Arcane Orb can deal significant damage and make him vulnerable to a follow-up from Nyx Assassin.
* Spiked Carapace is also the perfect tool against Astral Imprisonment: if used on Nyx, he can reflect the damage back as he comes out of the prison by casting the ability while imprisoned.
Nyx Assassin
* A well-timed 
Doom prevents Nyx Assassin escaping with Vendetta and fighting back with Spiked Carapace.
* Doom's high health also allows him to easily shrug off Nyx Assassin's burst damage and fend him off.
Sven
* Doom generally does not impede Sven in almost any way, provided he has activated God's Strength beforehand.
Nyx Assassin
* Nyx Assassin's skillset is mostly single-targeted, therefore he will have difficulties against heroes with illusions and summons: Naga Siren, Broodmother, Lycan, Visage, Phantom Lancer. And to make things worse, Nyx Asassin is not a common Battle Fury, Maelstrom, Mjollnir, Gleipnir or Radiance wielder to counter this problem.
Sven
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, 
Medusa, Templar Assassin, Gyrocopter, 
Muerta.
Sven
* Muerta's attacks during 
Pierce the Veil ignore Sven's Warcry.
* Sven using God's Strength can be completely ignored by using Pierce the Veil.
* Sven with Aghanim's Scepter will still not be able to dispel Muerta's Ethereal form during Pierce the Veil.
* However, Sven is a natural purchaser of Black King Bar that can protect him from Pierce the Veil and the rest of Muerta's kit.
Nyx Assassin
* Nyx Assassin's high burst damage, excellent ganking potential and multiple disables pose a threat to Muerta at all stages of the game.
* Mind Flare allows Nyx Assassin to take advantage of Muerta's high intelligence and make a short work of her low health.
* Spiked Carapace and Vendetta allow Nyx to escape or initiate well against Muerta's low mobility.
* As with most retaliation based abilities, Spiked Carapace can easily take advantage of 
Gunslinger's stray shots.
* However, Muerta is a natural Black King Bar wielder. And if she succeeds to activate it before Nyx Assassin can ambush her, he will go down very quickly against Muerta as Spiked Carapace cannot pierce through debuff immunity at all.
Sven
* Against her Untouchable, Sven is barely able to hit Enchantress even with his Black King Bar.
Nyx Assassin
* Vendetta can deal great damage against her. However, it requires an direct attack, so Nyx Assassin may have difficulties applying Vendetta on her.
* Enchantress's lack of mobility makes her a primary target for ganking with Vendetta.
* Mind Flare can deal a great damage against her due to being an Intelligence hero.
* Spiked Carapace can reflect Impetus and stun Enchantress.
Additional:
* Spiked Carapace reflects the damage from 
Impetus.
* Enchantress is a rather squishy hero, making her fall easily to Nyx Assassin's high burst damage.
Sven
* Heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him thanks to his 
Atrophy Aura, and will also be unable to ambush Underlord and his team if Underlord chooses to use 
Fiend's Gate to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, 
Drow Ranger, Phantom Lancer, 
Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.
Nyx Assassin
* Heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him thanks to his Atrophy Aura, and will also be unable to ambush Underlord and his team if Underlord chooses to use Fiend's Gate to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.
Sven
* Strong laners are usually at a disadvantage because of how well Sven can jungle. Heroes such as Dark Seer. Underlord and Legion Commander may find that later Sven takes care of them very quickly after some jungle farming.
Nyx Assassin
* Heroes with magical or pure damage output will not have any problems against Atrophy Aura at all: Luna, Lina, Jakiro, Pugna, Bane, 
Snapfire, Muerta, Nyx Assassin, Enigma, Tinker, Witch Doctor, Zeus, Crystal Maiden.
Sven
* Sven is very vulnerable to chain stun such as Lion, Shadow Shaman or Magnus.
Sven
* 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.
Nyx Assassin
* Heroes who build Black King Bar as either core or situational item will be able to fight back against Nyx Assassin and freely attack him as Spiked Carapace cannot pierce spell immunity at all: Axe, Broodmother, Dawnbreaker, Enigma, Huskar, Jakiro, Legion Commander, Lina, Luna, Lycan, Slardar, Slark, Troll Warlord, Witch Doctor.
Sven
* Heroes who cannot prevent Sven from killing supports will always be at a disadvantage in fights such as Lina, Slark and Zeus.
Sven
* Sven can be easily kited since Weaver is a natural 
Linken's Sphere carrier and Sven relies on Storm Hammer to disable and kill a hero.
Nyx Assassin
* Spiked Carapace allows Nyx to get an easy long-duration stun on Weaver once he uses Shukuchi, and then he can follow up with Impale.
* Vendetta works as a great setup for both Impale and Spiked Carapace and can deal decent damage to Weaver. Additionally he can neutralize The Swarm beetles due to his invisibility duration.
Sven
* His Heartstopper Aura deals the same gradual damage over time no matter how high Sven builds his strength or health pool up, and should he fall down to a certain percentage, his high health will no longer matter if Necrophos manages to land his Reaper's Scythe, killing him instantly. But it is best if Necrophos can either catch him off guard before he can possibly use his Black King Bar (which is an item Sven players commonly purchase), or bait him out of it.
* Ghost Shroud prevents Sven from hitting Necrophos, and if he doesn't have his Storm Hammer available, it could make him completely immune to Sven and allow Necrophos to easily kite him around.
Nyx Assassin
* The huge physical damage taken from Vendetta will force Necrophos to use Ghost Shroud, which is good for a followup with Dagon and 
Ethereal Blade, both of which are common items on Nyx Assassin.
* Using Ghost Shroud also sets Necrophos up for a Mind Flare or Impale.
Nyx Assassin
* Lycan's high health allows him to easily shrug off Nyx Assassin's burst damage and fend him off.
* As Lycan commonly buys Black King Bar, he can use it to freely attack Nyx Assassin and chase after him with 
Shapeshift.
* Lycan can also use his wolves from 
Summon Wolves to attack Nyx Assassin while he has Spiked Carapace active without getting stunned himself.
Sven
* Great Cleave will kill Lycan's summons very rapidly.
* Warcry will allow Sven and his allies to tank Lycan's damage, which is mainly physical.
* Storm Hammer will damage and stun Lycan's as well as his summons.
Nyx Assassin
* Heroes who build Black King Bar as either core or situational item will be able to fight back against Nyx Assassin and freely attack him as Spiked Carapace cannot pierce spell immunity at all: Axe, Broodmother, Dawnbreaker, Enigma, Huskar, Jakiro, Legion Commander, Lina, Luna, Lycan, Slardar, Slark, Troll Warlord, Witch Doctor.
Nyx Assassin
* Enigma is fragile, and lacks escapes, being dependent on Blink Dagger for mobility. Ganking Heroes or Heroes with burst damage will likely kill him before he can do anything. Such Heroes include: Lina, Lion, Luna, Puck, Slark, Nyx Assassin, etc.
Additional:
* Enigma's uncontrollable damage from 
Malefice and 
Midnight Pulse make him easy to stun with Spiked Carapace.
* 
Black Hole can be easily interrupted by Impale or Spiked Carapace.
Nyx Assassin
* Heroes who build mana boosting items but have low mana regeneration are especially vulnerable against Mana Break and Mana Void: 
Timbersaw, Slark, Shadow Fiend, Clinkz, Bristleback Nyx Assassin, Magnus
Sven
* Sven's Great Cleave can clear Anti-Mage's illusions from Manta Style and his high health pool and low mana, making Mana Void very ineffective, although keep in mind that Storm Hammer is extremely easy to reflect with a well-timed Counterspell.
Additional:
* Anti-Mage is fairly fragile, and cannot stand against Sven in a prolonged fight.
* Sven's Black King Bar and low base mana can protect Sven from the effects of 
Mana Break and 
Mana Void.
* Great Cleave destroys the illusions from Anti-Mage's Manta Style.
* Although Sven should be careful as a well-timed 
Counterspell can block and reflect Storm Hammer back at Sven.
Nyx Assassin
* Duel's long duration prevents Nyx Assassin escaping from Vendetta. With Aghanim's Scepter, she can also bypass Spiked Carapace.
Sven
* God's Strength makes Sven one of the worst heroes to Duel.
* Storm Hammer can be used to interrupt Duels.
* Warcry gives a big boost in passive defensive ability with the active component to nearby allies.
* With the Aghanim Shard Warcry also gives nearby allies passive increases.
Sven
* Pugna can save allies with both healing or by making them ethereal but needs to be careful of Sven's Aghanim's Scepter purge.
Nyx Assassin
* 
Nether Blast's animation makes it easy to time Spiked Carapace for a stun.
* Pugna has the largest intelligence gain in the game, making him a prime target for Mana Burn.
* Pugna needs to channel 
Life Drain, making him easy to hit with Impale.
Additional:
* Due to Pugna's incredible intelligence growth and terrible strength growth, Nyx should always be able to take you out with his combo, with or without an added Dagon. Mind Flare will deal a large amount of damage in particular, especially in the late game.
* Spiked Carapace is also a great tool versus Pugna. A good player will wait for you in Vendetta until you farm a creep wave with Nether Blast and reflect it back at you as their initiation and setup for Impale.
Sven
* Stone Gaze allows Medusa to easily kite and kill Sven.
* Mana Shield negates much of Sven's burst damage.
Additional:
* 
Mana Shield makes it very hard for Sven to burst her within Storm Hammer's stun duration.
* 
Stone Gaze makes it very difficult for Sven to fight Medusa at any stage of the game.
* 
Mystic Snake can slow Sven down enough for allies to capitalize on his commitment in a fight.
Nyx Assassin
* Vendetta burns a significant amount of mana on hit, and the damage from the ability drains Medusa's mana pool even further.
* Due to the passive nature of Mystic Snake and Split Shot, it can possibly proc Nyx's Spiked Carapace if he's within range of Medusa's abilities and isn't invisible.
* Medusa lacks single target damage, making Nyx with Aghanim's Scepter extremely hard to deal with if Medusa is the team's main damage source.
Additional:
* With her passive 
Split Shot, Medusa can be easily interrupted by Spiked Carapace during combat, especially during her precious Stone Gaze.
* Mana Burn quickly destroys Mana Shield, especially if Medusa only increases her mana pool by bolstering intelligence (which has the added bonus of increasing Mana Burn's damage).
* Uncontrollable damage from Mystic Snake and Split Shot can trigger Spiked Carapace.
* Medusa lacks single target damage, making a Burrowed Nyx Assassin hard to kill.
Nyx Assassin
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, Viper, Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom, Dawnbreaker. However, this also means they are easily stunned.
Sven
* Strong laners are usually at a disadvantage because of how well Sven can jungle. Heroes such as Dark Seer. Underlord and Legion Commander may find that later Sven takes care of them very quickly after some jungle farming.
Sven
* Sven is very vulnerable to chain stun such as Lion, Shadow Shaman or Magnus.
Nyx Assassin
* Nyx Assassin, Bounty Hunter and Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with 
Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.
Sven
*
Berserker's Call prevents Sven from bursting his targets before Axe can interfere. The worst kind of opponent for Sven is one who can stop him from attacking who he wants to, which is exactly what Axe does.
Culling Blade may finish off Sven before he has the chance to lifesteal or run with Warcry.
Blade Mail carrier which will make very short work of a Sven with God's Strength activated.
*
* Axe is a very common
Nyx Assassin
* A well-timed
Berserker's Call can expose Nyx Assassin while he is invisible with Vendetta, and prevent him from using Spiked Carapace.
Battle Hunger's damage over time to minimialize effects of Spiked Carapace.
Heart of Tarrasque wielder, which can completely eliminate any chance for Nyx Assassin to kill Axe alone.
Culling Blade can often kill Nyx Assassin as he is very fragile and vulnerable to damage while Spiked Carapace is on cooldown.
Berserker's Call can expose Nyx Assassin while he is invisible with 
Vendetta, and prevent him from using 
Spiked Carapace.
Battle Hunger's damage over time to minimialize effects of 
Spiked Carapace.
Heart of Tarrasque wielder, which can completely eliminate any chance for Nyx Assassin to kill Axe alone.
Culling Blade can often kill Nyx Assassin as he is very fragile and vulnerable to damage while Spiked Carapace is on cooldown.
* Axe can use
* Axe's high health also allows him to easily shrug off Nyx Assassin's burst damage and fend him off. Especially since Axe is a common
*
Additional:
* A well-timed
* Axe can use
* Axe's high health also allows him to easily shrug off Nyx Assassin's burst damage and fend him off. Especially since Axe is a common
*