* 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.

* Meepo is the hard counter for Queen of Pain - chain of Earthbinds prevents her from using Blink for a long time, and without any other escape options, Queen of Pain cannot survive several Poofs and attacks.
* Meepo tends to build items with attributes, mitigating Queen of Pain's magical burst.
Additional:
* Chain of Earthbinds prevents her from using Blink, allowing Meepo to quickly kill her with Poof and attacks.
* Meepo tends to buy items with attributes, mitigating Queen of Pain's magical burst.

* Necrophos struggles at clearing away durable illusions or summons. Meepo can overwhelm Necrophos with his many duplicates, especially in the later stages of the game, and his Earthbind will prevent Necrophos from getting away, even if he casts Ghost Shroud.
* Meepo's high burst damage from {Ability ID:Poof|Meepo} and {Item ID:Ethereal Blade} can make it difficult for to Necrophos to stay alive, and as Necrophos excels in extended fights, he will not be able to do as much damage as he intends to.

* 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 Mana Burn or Impale.

* Earthbind, like any root, inhibits usage of Ball Lightning, eliminating Storm Spirit's mobility.

* Mana Burn 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.
Additional:
* Mana Burn removes much-needed mana for Ball Lightning.
* Spiked Carapace triggers on Static Remnant for an easy stun.

* Heroes that can jump and kill him: Meepo, Clinkz, Templar Assassin

* Mana Burn is strong against Keeper of the Light due to his high mana pool.
* 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.

* Spiked Carapace stops Snapfire's Mortimer Kisses.
* Snapfire's low armor and agility gain means that Vendetta will deal a decent amount of damage.

* Heroes with high movement speeds like Pugna and Meepo can run around, to, or away from Snapfire during Mortimer Kisses and dodge the projectiles easily due to their slow speed.
* Heroes with mobility spells (such as Queen of Pain's Blink and Clockwerk with Hookshot) can easily avoid Lil' Shredder and Mortimer Kisses.
* Heroes with high movement speeds like Pugna and Meepo can run around, to, or away from Snapfire during Mortimer Kisses and dodge the projectiles easily due to their slow speed.

* Heroes with invisibility: (Riki, Clinkz, Nyx Assassin

* Meepo can net Nature's Prophet's treants with Earthbind and then he Poofs them. Putting an end to his pushing.
* Skilled Meepo can rival and even exceed Nature's Prophet's global presence by combining Poof with Boots of Travel, meaning that he can not only stop his push, but also can kill him if he is not careful.

* His whole skillset acts like a counter to Tinker:
* Impale prevents Tinker from blinding Nyx Assassin or fighting back, while giving Nyx' allies time to catch up to Tinker's position.
* Mana Burn 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.
Additional:
* March of the Machines and 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.

* Tinker who can't fight multiple heroes will suffer greatly against Ransack and Earthbind.

* Skywrath Mage's abilities are single targeted and he can't use Mystic Flare to its fullest potential, since all Meepos spread the damage between them. He also has no disables to prevent Meepo from Poofing to another one (unless he can get Ancient Seal off first).

* 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.
* Mana Burn is annoying at all stages of the game as it turns Skywrath Mage's high intelligence growth against him.
* Spiked Carapace gives Nyx some degree of protection against Skywrath's spells.

* Heroes with high mobility can be prevented from using it to their advantage with Earthbind, even if they pack a dangerous arsenal: Earth Spirit, Ember Spirit, Storm Spirit, Nature's Prophet, Phantom Assassin, Riki, Anti-Mage, Weaver.
* See items and abilities disabled by roots

* 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.

* Meepo is unlike any other multi-unit enemy Phoenix may face in the battlefield. Unlike illusion-based heroes like Phantom Lancer or Chaos Knight, Meepo's clones are not illusions, meaning they can deal full damage to the Phoenix Sun if all four (or five) are present.
Additional:
* Earthbind can prevent Phoenix from using Icarus Dive, the only escaping mechanism of this hero.
* Heavy burst damage from Poof can easily kill Phoenix even when it slows down all the Meepos with Fire Spirits.
* Meepo's clones destroy the Phoenix Sun from Supernova in no time, even when they are slowed down by Fire Spirits.
* Meepo's naturally high magic resistance gives Phoenix a hard time with bursting him down. He can even turn the tide if Icarus Dive is on cooldown.

* Silence (and mana burns) will be a persistent problem for Phoenix, as it is heavily reliant on its abilities whether defensively or offensively, so heroes like Death Prophet, Skywrath Mage, and even Nyx Assassin must be closely observed to prevent being shut down by these heroes.
* Hexes are a greater threat to Phoenix as they also disable items, preventing Phoenix from dispelling the debuff on its own.

Additional:
* Spiked Carapace reacts on any of the damage over time from Phoenix's abilities and can interrupt Sun Ray and Icarus Dive.

* Pugna's Nether Ward doesn't really hurt Meepo since he usually buys attribute items to tank up and can be killed very quickly by 4 clones. Decrepify can amplify Poof's damage should Pugna use it to avoid Meepo's right clicking.

* 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. Mana Burn 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.
Additional:
* 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.

* Vendetta breaks Untouchable and deals great damage against her.
* Enchantress' lack of mobility makes her a primary target for ganking with Vendetta.
* Spiked Carapace can reflect Impetus and stun Enchantress.
* Mana Burn can deal tremendous damage against her due to being an Intelligence hero.
Additional:
* Vendetta disables Untouchable.
* Spiked Carapace reflects the damage from Impetus.
* Enchantress is a rather squishy hero, making her fall easily to Nyx Assassin's high burst damage.

* Meepo can quickly kill Enchantress with a Poof combo, rendering Untouchable useless.

* 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 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 Devourer's high mana pool, high intelligence, and low health makes him a prime target for Mana Burn.
* If timed correctly, Spiked Carapace will return the full damage from Sanity's Eclipse back to Outworld Devourer. 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.

* Poof combined with Earthbind can be used to easily lockdown and burst Spectre down.
* As Meepo's playstyle is often to come online early to mid game and take over the whole game, Meepo will often be much further ahead of Spectre in farming.
* Meepo's global map presence allows him to effectively hunt for Spectre and disrupt her farm.
* Spectre has no strong AOE abilities or way to control or lock down Meepo.

* Poof will destroy Shadow Demon's illusions created by Disruption and quickly escapes from Shadow Poison & Demonic Purge.

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

* 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.

* Poof from multiple Meepos will destroy illusions quickly.
* Earthbind's area root can catch Phantom Lancer in a group of illusions and prevent him from using Doppelganger for a long time.
Additional:
* Poof will destroy Phantom Lancer's illusions within a short time.
* Earthbind prevents Phantom Lancer from using Doppelganger.

* Thundergod's Wrath strikes only the first Meepo.
* Zeus has low mobilty so consecutive Earthbinds are easy to hit and he'll quickly die from Poofs.

* Many of Nyx Assassin's abilities are good against Windranger.
* Impale is great for stunning Windranger and allowing additional disables to be landed.
* Mana Burn is useful against Windranger's decent intelligence growth and also burns some mana, preventing her from using more abilities.
* 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.

* Silencer is rather squishy and has poor mobility without items, making him an easy target for Nyx.
* Mana Burn will deal increasing damage for each 2 points of intelligence Silencer has stolen, turning Silencer's intelligence steal against him.

* Meepo can tank Eclipse because of his clones.
* Earthbind takes away Luna's mobility advantage.
* Meepo can shutdown Luna's split-push ability with his global presence.

* Nyx Assassin has a lot of burst damage from his Impale, Mana Burn, 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.

* 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 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:
* Spike 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.

* Earthbind prevents Mirana from Leaping or going invisible with Moonlight Shadow. She can be easily killed by Poof and Ransack while disabled.
* Landing a Sacred Arrow on Meepo does not render him helpless, as all of the other Meepos can still fight back.

* Ogre Magi has single-targeted magical-only damage and disables and is less effective against Meepo's clones.

* Root is a deadly threat to Riki, disabling both Blink Strike and Tricks of the Trade while making him fully revealed, making Earthbind a good ability against him.
* Smoke Screen may not be able to silence all the Meepo clones.
* Riki has no true area damage, as Tricks of the Trade's damage is distributed between all Meepo clones, so he cannot effectively fight Meepo or deal with his strong ability to push.

* Earthbind prevents Broodmother from escaping Meepo's attacks.
* Poof will quickly clear any nearby spiders.
* Broodmother wants to pick off single target heroes. With Meepo's Divided We Stand, it gets a lot harder once every Meepo Poofs in.

* Heroes with high mobility can be prevented from using it to their advantage with Earthbind, even if they pack a dangerous arsenal: Earth Spirit, Ember Spirit, Storm Spirit, Nature's Prophet, Phantom Assassin, Riki, Anti-Mage, Weaver.
* See items and abilities disabled by roots

* 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.
* Mana Burn is also good, as Ember Spirit relies on his limited mana pool for the early to midgame.
Additional:
* Spiked Carapace can be easily triggered by Flame Guard or Battle Fury, setting up a deadly Impale.

* Slark's Dark Pact and Pounce can deny only one Earthbind and Poof can penetrate Shadow Dance if he doesn't build Black King Bar.

Additional:
* Earthbind and Poof will still hit Slark in Shadow Dance.
* Dark Pact can only remove one Earthbind.
* Ransack will still affect Slark, even if he has a Black King Bar.

* Nyx Assassin can reflect Life Break with Spiked Carapace.

* Heroes that can pick you off: Clinkz, Nyx Assassin, Puck, Riki.

* Heroes with high mobility can be prevented from using it to their advantage with Earthbind, even if they pack a dangerous arsenal: Earth Spirit, Ember Spirit, Storm Spirit, Nature's Prophet, Phantom Assassin, Riki, Anti-Mage, Weaver.
* See items and abilities disabled by roots

* Multiple attackers thanks to summoned units or clones: Meepo, Witch Doctor, Lycan, Enigma, Shadow Shaman
* Heroes that can quickly deal damage to her, regardless of how weak they are, can easily break through her Refraction:
* Multiple attackers thanks to summoned units or clones: Meepo, Witch Doctor, Lycan, Enigma, Shadow Shaman
* Multiple attackers thanks to illusions: Phantom Lancer, Chaos Knight, Naga Siren (bonus for her Ensnare). Also despite the visual effects, Templar Assassin does not spill damage against illusions or buildings, so she is not a really good hero to clean up illusions.
* Weak damage but high tick rate or persist in a long time: Slark, Gyrocopter, Queen of Pain, Shadow Shaman (Shackles), Pugna

* Heroes who can drain mana can make Omniknight useless after he uses one or two abilities: Lion, Anti-Mage, Nyx Assassin

* Heroes with damage burst can often kill Chen or his allies before he can use Hand of God: Lina, Techies, Shadow Fiend, Pugna, Nyx Assassin.

* Meepo can quickly destroy Tombstone thanks to Divided We Stand.

* Meepo can just mess up Naga Siren entirely: His Earthbind is AoE, which can bind her illusions, his Poof is a powerful AoE nuke and will clear her illusions. He is also 2/3/4 Meepos, not one, so her Ensnare will not work efficiently against him.

* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Meepo, Broodmother

* Arc Warden's Flux is meaningless against Meepo who loves to group up. Meepo is also a very good gap closer, so Arc Warden's Magnetic Field becomes useless.

Additional:
* Flux is severely impaired against Meepo because of Divided We Stand.
* Meepo's farming speed and early powerspikes allows him to pressure Arc Warden before he is capable of fighting effectively.
* Without Black King Bar, Earthbind and Poof can finish Arc Warden quickly before he has time to do much.

* Nyx Assassin, Bounty Hunter and Slark can all sneak up and kill you, Nyx being particularly deadly. Watch Slark carefully, as he can break either (but not both unless you are making a mistake) of your 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 you from prey to predator.

* 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.

* Meepo has a better advantage in farm with Divided We Stand, as well as having a higher attack speed due to his tendency to build items that give attributes. In addition, Wraithfire Blast stuns only one target, and choosing to engage one Meepo will most certainly mean engaging them all.

* Nyx can walk into Firefly with Spiked Carapace and stun Batrider if he has no Spell Immunity.

* Mana Burn completely drains Pudge's little mana which may render Meat Hook & Dismember unusable.
* Impale and Spiked Carapace used to cancel Dismember if timed perfectly.
* Vendetta grants Nyx Assassin invisibility and a high degree of mobility for a long time, which can make Nyx a difficult target to hook. In addition, it also scouts out Pudge's location and surprising him with his attack, Impale and Mana Burn.

* Multiple Earthbinds allows Meepo to lock down Anti-Mage almost indefinitely.
* Meepo's clones can only use their mana for Poof, keeping their mana pool nearly full and thus making them a bad target for a Mana Void.
Additional:
* Earthbind can prevent Anti-Mage from using Blink, allowing Meepo to kill him with attacks and Ransack.

* Meepo's Earthbind can easily lockdown Void Spirit.
* Meepo and his clones can easily burst Void Spirit's Resonant Pulse.

* Earthbind's root prevents/interrupts Charge of Darkness.
* As a single target focused hero without much damage output, Spirit Breaker is ineffective in general against Meepo. Consider upgrading Nether Strike with Aghanim's Scepter to spam AoE stuns against Meepo clones.
Additional:
* Spirit Breaker heavily relies on disabling one enemy at a time therefore rendering him useless against five Meepos at once.

* Mana Burn can instantly deplete Tidehunter's low mana pool, especially in the early game, potentially preventing Tidehunter from casting Ravage.
* Ravage's travel time allows Nyx Assassin to easily stun Tidehunter with Spiked Carapace.
* Vendetta offers a very rare break effect, which fully disables Kraken Shell and makes Tidehunter susceptible to follow-up disables.

* 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 Mana Burn that much more deadly against Puck.
* An ill-timed Phase Shift can easily set himself up to be stunned by Impale.
Additional:
* 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.

* Heroes with high mobility can be prevented from using it to their advantage with Earthbind, even if they pack a dangerous arsenal: Earth Spirit, Ember Spirit, Storm Spirit, Nature's Prophet, Phantom Assassin, Riki, Anti-Mage, Weaver.
* See items and abilities disabled by roots

* Ethereal state disarms the target and makes them more vulnerable to magic damage, both of which Phantom Assassin despises. Especially Pugna and any hero that is wielding Ethereal Blade, such as Mirana, Nyx Assassin or Morphling.

* 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.
Additional:
* Level 4 Mana Burn burns 38,5% of Medusa's mana every 4 seconds if Medusa only increases her mana pool with intelligence. Additionally, 60% of the Mana Burn damage gets mitigated by Mana Shield, burning even more mana.
* 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.

* Mana Burn does tons of damage against Lina because of her high intelligence. The mana burn also prevents Lina from casting her full combo.
* 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.

* Vendetta disables Vengeance Aura and allows him to attack Vengeful Spirit with Impale and Mana Burn.
* Spiked Carapace is easy to use against a Wave of Terror or Magic Missile.

* Once you've taken a point in Retaliate, Nyx can easily initiate on you: he can use Spiked Carapace and hit you with Vendetta. The damage from Retaliate will be reflected back to you, stunning you with no chance to react after he's revealed himself, and should guarantee a successful Impale.

* When Legion Commander uses Duel on one Meepo, he can use his other Meepos to kill her. If he wasn't dueled, he can help the teammate who was duelled to give the teammate the damage instead of Legion Commander.
* However, if Legion Commander picked up an Aghanim's Scepter and she duels one Meepo, that might be the end of Meepo if Legion managed to gather enough damage from previous duels.

* Large area-of-effect with delay or require channeling: Enigma, Crystal Maiden, Invoker, Shadow Fiend, Pugna, Keeper of the Light
* The nature of some abilities turn them into an easy target for a turnover from Spiked Carapace:
* Slow-moving projectiles: Skywrath Mage, Tinker, Necrophos
* Large area-of-effect with delay or require channeling: Enigma, Crystal Maiden, Invoker, Shadow Fiend, Pugna, Keeper of the Light
* Deals damage over time: Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom

Additional:
* Nyx Assassin takes advantage of Invoker's massive intelligence gain and mana pool to do tons of damage using Mana Burn, as the spell does more damage based on the target's intelligence.
* Nyx Assassin can simply activate Spiked Carapace while under many Invoker's abilities to stun him.

* Nyx Assassin's Spiked Carapace will stun Leshrac when hit by any of his AOE abilities.
* Mana Burn deals high damage due to Leshrac's high intelligence gain and burns a large amount of Leshrac's essential mana pool.

* Impale interrupts Upheaval.
* Nyx Assassin Vendetta allows him to escape from Warlock's Upheaval with maximum move speed.
* Warlock's low health pool and mobility can easily take down by Nyx Assassin's burst damage.

* 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.

* Night Stalker's most skills are single targeted which allows other Meepos to Poof, Earthbind and kill him.

* 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, 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.