* Jumping on Axe with Waveform will make Morphling an easy target for a counter-initiation with Berserker's Call.
* Morphling is often played at low health to maximize the bonuses from Attribute Shift (Agility Gain), and also because his abilities cost health to use. This makes him especially vulnerable to Culling Blade.
* However, Morphling is a common Linken's Sphere carrier to block Culling Blade, which may force Axe to use Battle Hunger to pop the Spell Block first.
* Attribute Shift (Agility Gain) gives Morphling no protection against the pure damage of Culling Blade. Its attack speed bonus also means that Counter Helix will proc more often.

* A well-timed Berserker's Call can expose Nyx Assassin while he is invisible with Vendetta, and prevent him from using Spiked Carapace.
* Axe can use Battle Hunger's damage over time to minimialize effects of Spiked Carapace.
* 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 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.
Additional:
* A well-timed Berserker's Call can expose Nyx Assassin while he is invisible with Vendetta, and prevent him from using Spiked Carapace.
* Axe can use Battle Hunger's damage over time to minimialize effects of Spiked Carapace.
* 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 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.

* Time Dilation affects Morphling's low cooldown spells, making them unusable for a long time, rendering Morphling nearly useless.
* Morphling cannot use Attribute Shift while he is inside Chronosphere which makes it easy to kill him.

* Heroes who rely on invisibility, such as Bounty Hunter, Clinkz, Mirana, Nyx Assassin and Riki, as they will be revealed if caught by Chronosphere.

* Counterspell's bonus magic resistance causes the Waveform and Adaptive Strike combo to deal significantly less damage.
* Counterspell's active component can reflect the Adaptive Strike back into Morphling, dealing significant damage or even killing him.
* Mana Break combined with Manta Style can quickly burn away Morphling's mana, leaving him unable to use his spells. Black King Bar can no longer be reliably used against Anti mage due to its 50 mana cost.

* 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

* Morphling usually has low max health due to shifting strength into agility, which combined with Blast Off's silence will prevent him from using Waveform and Adaptive Strike (Strength), leaving him defenseless and making him an easy target to burst down.

* 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.

* Phantom Lancer can effortlessly overwhelm Morphling with a large number of illusions. It becomes even more effective with {Item ID:Diffusal Blade}, which takes away his mana in the process.
* Doppelganger can be used to dodge Adaptive Strike combo and create confusion with two additional illusions.
* Eye of Skadi can be bought to slow and negate the health regeneration from Attribute Shift, and a common item for Phantom Lancer.

* 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.

* Heroes that rely on right-clicks will find that their attacks will miss a lot, due to Whirling Axes (Melee)'s miss chance. Such heroes include Phantom Assassin, Terrorblade, and Morphling.

* 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.

* Jakiro's early pushing ability from Liquid Fire makes Jakiro very strong against heroes, that take a long time to get online: Morphling, Naga Siren, Spectre.

* 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.

* Heroes with blink or movement abilities, which are disabled by Pounce's leash: Anti-Mage, Earth Spirit, Faceless Void, Magnus, Mirana, Monkey King, Morphling, Pangolier, Phantom Assassin, Phoenix, Puck, Queen of Pain, Riki, Sand King, Spirit Breaker, Timbersaw, Tusk.

* 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.

* 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.

* Morphling's high armor is primarily from morphing agility, which is reduced by Natural Order therefore making the hero very vulnerable when it has morphed a lot into agility.
* Morphling usually will Morph into high agility and low strength. This can be taken advantage of with a good stun or silence or by bursting him down before he has the time to Morph back to strength.
* Morphling is very vulnerable to Blade Mail under Natural Order and can easily burst himself down with his own auto-attacks or his magical damage combo.
Additional:
* Most of Morphling's armor comes from his high agility and it is reduced by Natural Order.
* However, the aura has only 350 range and Elder Titan can be bursted down by Morphling's nuke combo if he isn't careful.

* Duel's long duration prevents Nyx Assassin escaping from Vendetta. With Aghanim's Scepter, she can also bypass Spiked Carapace.

* 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.

* 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.

* Earthbind disables Waveform, effectively keeping Morphling in place for an extended period of time, allowing Meepo to deal considerable damage with Poof.

* Geomagnetic Grip is not blocked by Linken's Sphere and can silence Morphling, preventing Morphling from using Waveform or Attribute Shift to escape from ganks.
* In addition, Boulder Smash and Rolling Boulder provide a solid lockdown if used together.

* Void Spirit can greatly pressure Morphling's farm, which is very bad for a hero who needs a large amount of space.
* Waveform does not provide better mobility than Astral Step.
* If Morphling shifted all of his strength to agility, he can be bursted down by Void Spirit before he can react.
* Doing an Ethereal Blade combo on Void Spirit is incredibly difficult, as Dissimilate and Astral Step can allow him to escape or dodge the projectile.

* 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.

* Cyclone from Storm in Primal Split can waste Nyx's Spiked Carapace, since its duration is shorter than the Cyclone's.

* 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.

* Rubick's ability to steal Attribute Shift (Strength Gain) makes him extremely annoying to deal with because Rubick's shifted attributes will remain even if he steals a new spell.
* If Rubick moves enough points to strength and then steals Adaptive Strike, he will have a powerful 3-second ranged stun in his arsenal as well.
* Waveform provides a reliable nuke/escape to Rubick.
* Rubick can steal most abilities Morphling uses while Morphed, allowing Rubick to steal his own allies' abilities if the Morphling is not careful.
Additional:
* Morphling's abilities can grant unrivaled utility for Rubick.
* Attribute Shift (Strength Gain) is a great spell that has a longlasting effect, since the attribute change is permanent even after losing the ability. By casting the spell, Rubick becomes significantly tanky after pumping all his agility into strength.
* As the cost of the shift, Rubick's attack speed as well as his armor is hindered. Since the right click damage of Rubick is relatively trival in teamfights, armor items such as Medallion of Courage or Buckler could greatly increase Rubick's effective health to physical damage.
* Rubick must be careful not to confuse Attribute Shift (Strength Gain) with Attribute Shift (Agility Gain).
* Adaptive Strike (Strength) is a long-ranged stun.
* If Attribute Shift (Strength Gain) has been stolen and cast, the spell can stun the enemy for 3 seconds. The stun counters mobile heroes such as Morphling.
* Waveform is a damaging pseudo-blink, giving Rubick much needed mobility and farming potential.

* 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.

* 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.

* Mana Drain rapidly saps Morphling's already low mana pool, making him unable to use Waveform or Adaptive Strike. Additionally, Hex prevents these abilities as well.
* An Earth Spike and Finger of Death combo can burst an unwary Morphling down if he has his strength fully shifted to agility.

* 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.

* Sacred Arrow's long stun duration can prevent Morphling from casting his Waveform or Morph Replicate, making him unable to escape and easier to gank.
* Moonlight Shadow also allows Mirana's team to surprise Morphling while he tries to push towers.
* Mirana usually buys Linken's Sphere to protect herself from single-target abilities, making Morphling's Adaptive Strike and Ethereal Blade harder to use on her.
* However, Mirana also provides a chance to become a good Morph target, allowing Morph to use Leap to run away, if necessary.

* Underlord's Atrophy Aura reduces Morphling's high base damage gained through agility shift.

* 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.

* Heroes that have a weak laning stage: Spectre, Nyx Assassin, Clockwerk, Spirit Breaker, Omniknight, Pudge.

* Winter Wyvern's Winter's Curse turns Morphling's high attack damage and attack speed against his targeted teammate.

* 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.

* 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.

* 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.

* Light Strike Array catches Morphling while he jumps in from Waveform and also prevents Morphling from using his abilities.
* Laguna Blade can kill Morphling quickly before he shifts into Attribute Shift (Strength Gain).

* 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.

* 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.

* 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.

* Arc Warden can counter Morphling's strong pushing capabilities by using Magnetic Field to protect buildings.
* Arc Warden also often builds an Orchid Malevolence or Bloodthorn, which can prove dangerous for Morphling.
* Arc Warden can easily break Linken's Sphere with Flux and then slow him with Spark Wraith, making Arc Warden's Tempest Double a legitimate threat as well.

* Arcane Bolt's low cooldown allows him to deal consistent damage to Morphling, and is a viable way to disable Linken's Sphere.
* Ancient Seal prevents Morphling from using any of his skills, giving Skywrath Mage and his team ample time to burst Morphling down.
* Mystic Flare coupled with a stun/root can easily burst Morphling down, especially if he has more stats shifted to Agility.
* Alternatively, Morphling can use Morph to use Skywrath Mage's own silence and nukes against him.

* While Morphling can burst her down with Adaptive Strike (Agility), Death Prophet does have tools to disrupt him. A Morphling affected by Silence makes it unable to use Attribute Shift (Strength Gain) to increase its health pool or use Waveform to escape.

* Ice Blast stops Morphling from gaining additional health with Attribute Shift.
* Using Attribute Shift would even bring Morphling closer to the shatter threshold.
* In the lane, Ice Vortex slows Morphling's already poor movement speed to a crawl; this, coupled with the amplification of magic damage, can set up an early kill on Morphling if Ancient Apparition has a suitable lane partner.
Additional:
* Ice Blast stops Attribute Shift (Strength Gain) from recovering adional health, and using it will even bring Morphling closer to the shatter threshold.
* In lane, Ice Vortex slows Morphling's already poor movement speed to a crawl; this, coupled with the amplification of magic damage, can set up an early kill on Morphling if Ancient Apparition has a suitable lane partner.

* 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.

* Heroes with high base damage (Morphling, Tiny, Drow Ranger), heroes with mana burning abilities (Anti-Mage), and Diffusal Blade users (Juggernaut or Riki) will suffer from Reflection's illusions.

* Attribute Shift (Strength Gain) may not be quick enough to fend off an attacking Drow Ranger.
* Morphling likes to sit on low health with high agility, something Drow Ranger does not particularly care for and will still hit him hard with Marksmanship procs.
* Morph is a similar story, none of Drow Ranger's spells are particularly good against her.

* 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.

* Heroes with silencing abilities that are not blocked by Linken's Sphere, like Puck's Waning Rift, Death Prophet's Silence or Silencer's Global Silence.

* Necrophos's Reaper's Scythe can finish off a low-health Morphling.

* Heroes with silencing abilities that are not blocked by Linken's Sphere, like Puck's Waning Rift, Death Prophet's Silence or Silencer's Global Silence.

* 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.

* 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.

* 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.

* 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.

* Heroes who just want to farm and avoid Lone Druid early will find it very hard to do so when he starts knocking on towers: Templar Assassin, Phantom Assassin, Ember Spirit, Morphling.

* Sharpshooter can kill easy when Morphling is going on full agility strategy (Only in early and mid game).
* Scurry can help to catch up Morphling when using Waveform or for escape.

* 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.

* 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.

* Low-health, normally mobile carries who rely entirely on raw attack damage are vulnerable to Bane's nukes and disables: Anti-Mage, Clinkz, Drow Ranger, Faceless Void, Gyrocopter, Juggernaut, Meepo, Mirana, Monkey King, Morphling, Phantom Assassin, Phantom Lancer, Riki, Shadow Fiend, Slark, Sniper, Terrorblade, Troll Warlord, Weaver.

* 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.

* Arcane Orb deals pure damage, effectively bypassing Morphling's high armor from Attribute Shift (Agility Gain).
* Sanity's Eclipse is more effective against a low health and mana pool Morphling, enabling Outworld Destroyer to burst Morphling down before he can shift to Strength.
Additional:
* Arcane Orb deals high damage regardless of Morphling's high armor from Attribute Shift (Agility Gain).
* Because of Morphling's very low intelligence gain and base intelligence, Sanity's Eclipse will almost always be effective against Morphling.

* 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.