* Heroes with abilities that blind or cause Legion Commander to miss will prevent her from winning Duels: Arc Warden, Keeper of the Light, Riki, Tinker

* All assassin-type carries in a one against one situation: Meepo, Phantom Assassin, Riki, Ursa. Luna's only chances are that she buys Ethereal Blade or Black King Bar to gain a slight edge against them, or both items if necessary.

* 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.

* Nyx Assassin might not kill Abaddon with his nuke, but a support Abaddon will struggle to protect an ally from him.

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

* Heroes with escaping and disjointing abilities can be good against Juggernaut:Anti-Mage Riki, Queen of Pain, Puck, Storm Spirit, Ember Spirit, Slark etc.

* Riki usually buys Diffusal Blade to initiate, which renders Enchantress' movement speed useless, and is usually followed with Smoke Screen.
* Riki can effectively hit Enchantress by Tricks of the Trade alongside with Diffusal Blade and Smoke Screen's initiation. For a hero like Enchantress, 3 to 4 hits from Riki is a big deal, unless Enchantress built Force Staff earlier.

* 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.

* Sniper has no natural escape and relies on his range and slows to keep himself safe, which Riki can bypass with Blink Strike and quickly deplete his miniature HP pool.

* 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.

* Smoke Cloud prevents Storm Spirit from using any of his offensive and defensive spells, rendering him unable to effectively react to Riki's attack.
Additional:
* Smoke Screen prevents Storm Spirit from using his abilities once inside the radius. Riki can utilize this ability to allow his team to fight around Smoke Screen so that Storm Spirit cannot spam his spells to proc Overload.

* 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.

* Smoke Cloud prevents Queen of Pain from using any of her offensive and defensive spells, rendering her unable to effectively react to Riki's attack.
* It's easy to dodge Sonic Wave by using Blink Strike & Tricks of the Trade.

* 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.

* Blink Strike gets Riki close to Drow Ranger and disable Marksmanship.
* Cloak and Dagger allow Riki stay close to Drow Ranger without her noticing him, which allows him to disable Marksmanship.
Additional:
* With Blink Strike, Riki can get close to Drow Ranger and disable her Marksmanship, and Smoke Screen will prevent her from using Gust.

* 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.

* Smoke Screen prevents Dark Willow from using her abilities, rendering her defenseless and unable to deal any serious damage.
* Blink Strike lets Riki jump past Bramble Maze.

* 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.

* Smoke Cloud prevents Shukuchi and Time Lapse, leaving Weaver helpless against Riki.
* The Swarm is ineffective against Riki because invisibility instantly removes the beetles.

* 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.

* With Smoke Screen, Riki will silence and catch Medusa in a surprise with high miss chance flushing her from positions easily in team fights.
* He can deal a huge amount of damage through Cloak and Dagger, even through Mana Shield.

* 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.

* Heroes with silence: Death Prophet, Riki, Drow Ranger.

* 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.

* Riki and Disruptor: Smoke Screen and Static Storm, respectively, can be thrown wherever Puck used Phase Shift, making Puck an easy target if it doesn't have Blink Dagger or is on cooldown. Puck is also very susceptible to Riki's high attack damage when attacking from the back. Glimpse also prevents Puck from escaping altogether.

* 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.

* Heroes with silences: Puck, Doom, Riki.

* 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.

* Heroes with a high degree of mobility and invisibility are hard to catch with Meat Hook: Ember Spirit, Riki, Clinkz, Queen of Pain.

* 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.

* Heroes with damage-increasing passive abilities, such as Viper and Riki, will usually kill Silencer in a short time before he even has time to set up his abilities.

* 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.

* Riki can get on top of Ancient Apparition very easily with Blink Strike. This can also double as a way to dodge Ice Blast, along with Tricks of the Trade.
* Ancient Apparition will frequently resort to casting Ice Blast right before dying. Smoke Screen can be used to prevent this, stopping Ancient Apparition from having any impact.

* 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.

* Due to his low health and armor, Riki can easily kill Skywrath Mage.
* Smoke Screen prevents Skywrath from using all of his abilities, as he does not tend to buy Black King Bar.
* However, Skywrath Mage can easily kill Riki if he manages to root Riki with Rod of Atos or Gleipnir, followed by Dust of Appearance, Ancient Seal and Mystic Flare.

* 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.

* Warlock is a very strong hero when positioned correctly, and his long cast range helps him with this. However, some heroes might disrupt or sneakily pass through his allies and deal with him, preventing him from doing his job. Such heroes include Chaos Knight, Spirit Breaker, Riki, and more.

* 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.

* Riki is known for being a successful support killer, something Shadow Shaman is very vulnerable to.
* Smoke Screen is particularly devastating to Shadow Shaman. With neither his various disables nor a solid health pool Shadow Shaman is usually dead. This forces Shadow Shaman to buy a Force Staff if he finds himself in this scenario and buy Sentry Wards if you have the money.

* 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.

* Frail heroes who lacks mobility: Crystal Maiden, Enigma, Dark Willow, Vengeful Spirit.

* 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.

* Smoke Screen effectively disables Crystal Maiden's channeling spell: Freezing Field.
* Due to her low health and armor throughout the game, Riki can kill her 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 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.

* Heroes that can easily bypass Chen's creeps to get to Chen: Riki, Tusk, Clinkz, Sniper, Slark, Phantom Assassin, Void Spirit, Storm Spirit, Ember Spirit, Earth Spirit, Spirit Breaker.

Additional:
* Chen is basically Riki's natural prey: he has little HP, low armor and relies on his persuaded creeps to fight, which in most situations will not save Chen from Riki. Just be wary of {U:Centaur Conqueror}, who can stun Riki outside of Smoke Screen and ruin his attempt at Chen's life.

* 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.

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

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

* Heroes that can gank Shadow Fiend in the early game: Earth Spirit, Nyx Assassin, Riki, Spirit Breaker.

* Large area-of-effect with delay or require channeling: Enigma, Crystal Maiden, Invoker, Shadow Fiend, Pugna, Keeper of the Light, Dawnbreaker.

* Riki with Tricks of the Trade
* Heroes that can dodge Glimpse:
* Puck with Phase Shift
* Riki with Tricks of the Trade
* Phantom Lancer with Doppelganger
* Ember Spirit with Sleight of Fist and Activate Fire Remnant
* Chaos Knight with Phantasm
* Naga Siren with Mirror Image
* Tusk with Snowball
* Juggernaut with Omnislash
* Brewmaster with Primal Split
* Lifestealer with Infest
* Phoenix with Supernova

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

* Heroes that can easily bypass Io's allies to get to Io: Riki, Tusk, Clinkz, Sniper, Slark, Phantom Assassin, Void Spirit, Storm Spirit, Ember Spirit, Earth Spirit, Spirit Breaker, Lifestealer.

* 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 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.

* Spiked Carapace stops Snapfire's Mortimer Kisses.

* Heroes with abilities that can lock down Terrorblade and prevent him from using Sunder: Bane, Batrider, Earthshaker, Elder Titan, Faceless Void, Invoker, Legion Commander, Mars, Primal Beast, Riki, Shadow Shaman, Silencer, Vengeful Spirit, Void Spirit.

* 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.

* 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.

* 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.

* Riki has high damage and invisibility, meaning he can easily gank Rubick and kill him before Rubick has the chance to react.
* Cloak and Dagger renders Riki invisible, which makes his spells hard to steal if not being initiated.
* Similar to Clinkz, Rubick has to buy a large amount of Sentry Wards to keep track of Riki due to Cloak and Dagger, preventing Rubick from getting better items.

* 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.

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

* 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.

* 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.

* Riki can potentially catch an Enigma out of position and prevent him from properly blinking and initiating, thanks to Cloak and Dagger.
* Before Enigma gets his Black King Bar, Smoke Screen can be used to cancel Black Hole. After Enigma gets Black King Bar, Riki can also cancel Black Hole with Abyssal Blade, which is a common item built on him.
* Tricks of the Trade renders Riki hidden and invulnerable, which in combination with Abyssal Blade allows Riki to cancel Black Hole with little to no worries of getting caught in it.
* Enigma's fragility during all stages of the game makes him extremely prone to Riki's ganking.

* 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.

* 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.

* 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.

* Riki is a natural Diffusal Blade carrier, and it doesn't help that he's easily capable of sneaking up on Wraith King due to Cloak and Dagger.
* Riki can use Smoke Screen on top of Wraith King as he is reincarnating, making him a sitting duck for his second life. In addition, the blind prevents Wraith King from landing critical hits from Mortal Strike.
* Wraithfire Blast is quite predictable, and if Riki can react fast, he will disjoint it with Tricks of the Trade. There is also a chance he will become invisible again as the projectile travels, disjointing it.

* Riki can detect early Roshan attempts because of Cloak and Dagger if he frequently checks the Pit.
* Ursa cannot Enrage when in Smoke Screen (Black King Bar will help though).
* Even if Ursa gets vision over him, Riki can Blink Strike away or use Tricks of the Trade after Ursa's initiation to avoid all Fury Swipes damage until Earthshock's slow is gone.
Additional:
* Riki can detect early Roshan attempts because of Cloak and Dagger if he frequently checks the Pit.
* Ursa cannot Enrage when caught in Smoke Screen and will miss his attacks (although Black King Bar will help with this issue).
* Even if Ursa gets vision over him and initiates with Earthshock, Riki can Blink Strike away or use Tricks of the Trade after Ursa's initiation to avoid Fury Swipes' damage until Earthshock's slow is gone.

* Smoke Screen combined with Diffusal Blade leaves Arc Warden effectively useless for a while as he struggles to escape the silence with low mobility.
* With Arc Warden's low mobility, Tricks of the Trade often deal decent damage to him before he moves out of it.

* Heroes that have superior mobility that can easily catch up with Mirana even after she used Leap to escape: Anti-Mage, Queen of Pain, Storm Spirit, Riki.

* Because Templar Assassin does not have escape potential in lane, any support hero with roaming potential and a Dust of Appearance can be great at shutting her down early game: Earth Spirit, Spirit Breaker, Tusk, Bounty Hunter, Riki, Warlock.

* Like above, supports with reliable stuns can be a massive problem and force Black King Bar in fights unideally, such as Shadow Shaman, Lion, Nyx Assassin.

* Riki is another good hero to shutdown Death Prophet with Diffusal Blade as his core item. His Smoke Screen stops her from initiating and casting spells.

* Earthshaker must be careful not to use Blink Dagger or Aghanim's Scepter upgraded Enchant Totem to blink into Riki's Smoke Screen or Night Stalker's Crippling Fear, as these field effects will instantly silence Earthshaker and prevent him from initiating.

* Heroes with high armor like Dragon Knight, or with abilities to cause attacks to miss like Phantom Assassin, Riki and Tinker will be hard to deal with, as Clinkz relies almost entirely on physical attacks.

Additional:
* Smoke Cloud prevents the use of Death Pact, Searing Arrows and Skeleton Walk, so Clinkz can neither defend himself against Riki nor fight back effectively.
* It's hard to gank Riki as Clinkz has to find him first.

* Riki: Smoke Screen can prevent Lone Druid from using True Form and Savage Roar, additionally it cause the spirit bear to miss on attacks which reduce the chances of getting rooted from it, with diffusal Blade, he can keep Lone Druid or the Spirit Bear inside the Smoke.

* Blink Strike gives bonus backstab damage and can bypass Bulwark. Defensively, it could be used to teleport away from Mars, especially while inside Arena of Blood.
* Smoke Screen can interrupt Mars' skill combos, especially when cast inside Arena of Blood.
* Tricks of the Trade can be used to evade Mars' skills, which have a slight delay to them. It could also be used to buy himself time while trapped inside of Arena of Blood.
Additional:
* Bulwark is generally irrelevant against Riki as he primarily deals bonus damage from behind.

* 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.

* 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.

* 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.

* Without Dust of Appearance or Sentry Wards, Riki is able to silence Witch Doctor with Smoke Screen, and is likely to build a Diffusal Blade, leaving Witch Doctor without mana to cast Voodoo Restoration, as well as Skull Basher to interrupt Death Ward.

* 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.

* 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.

* 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.

* Heroes with blind of some sort can be a bad choice for Monkey King to go on: Broodmother, Riki, Keeper of the Light.

* Riki's Smoke Screen can make it hard for Spectre to escape or burst down Riki with auto attacks.
* Riki can build Aghanim's Scepter and jump inside an allied carry or offlane tank with Tricks of the Trade to do a lot of damage to Spectre while completely avoiding Dispersion.
* Riki is great at destroying supports which are often needed to keep Spectre safe until she comes online. He can take them down quickly in team fights, which will leave Spectre alone against your whole team, a fight that she will most likely not win.
* While on Tricks of the Trade, Riki does not take damage from Dispersion.

* Nyx Assassin can reflect Life Break with Spiked Carapace.

* Heroes with abilities or items that can silence or disable Anti-Mage for long periods of time will prevent him from Blinking away: Lion, Silencer, Shadow Shaman, Grimstroke, Witch Doctor, Riki, Faceless Void, Skywrath Mage, Puck.

Additional:
* Anti-Mage can use neither Blink nor Manta Style to escape from Smoke Cloud.
* Even if he activates a Black King Bar, his Manta Style illusions will still be blinded by Smoke Cloud.
* Riki has a very small mana pool and generally doesn't buy many items that increase it, making Mana Void ineffective.

* Lifestealer cannot use Rage, Infest or Open Wounds when affected by Smoke Cloud's silence, and Feast cannot heal him effectively because of the blind, leaving him very weak both offensively and defensively.
* Infest ganks are harder when the enemy team has a Riki, as there are often only four heroes on the map that you can initiate on.