* Mana Drain is very effective against heroes that have mana burn abilities such as Anti-Mage, Nyx Assassin and Keeper of the Light.

* Anti-Mage can easily withstand heavy magical burst due to Counterspell, but he is still somewhat vulnerable to physical damage. Phantom Assassin's burst physical damage can destroy Anti-Mage while Blink is on cooldown or while he is stunned or hexed.
* Blur makes Anti-Mage unable to deal significant damage to her.
* Phantom Assassin has an abysmal mana pool and intelligence gain, making Mana Break and Mana Void deal minimal damage.

* Dazzle's lack of a true disable makes him a relatively vulnerable target for Phantom Assassin.
* Coup de Grace will often kill Dazzle's teammates before he has a chance to use Shallow Grave.

* Heroes with high burst damage through their physical attacks or spells can kill Dazzle or his allies before he has a chance to use Shallow Grave. (Lina, Lion, etc.)

* Generally, heroes that can close the gap on Drow Ranger to cancel her Marksmanship such as Phantom Assassin, Spirit Breaker, and Tusk are effective at limiting her power and bursting her down.

* Drow has a very low health pool, allowing Lion to burst her down.
* Drow has no innate escape mechanism, making her an easy target for Lion's disables.
* Lion should be wary of Drow's Gust however, as he has no natural means to deal with it.

* Lion has two low cast point disables (Hex and Earth Spike) to control Ursa before he buys a Black King Bar.
* Hex is one of the few abilities that cannot be dispelled even with an Aghanim's Scepter upgraded Enrage.
* Lion can control Ursa's low mana pool via Mana Drain.

* Assuming they have not bought anti-evasion items, attack dependent heroes such as Viper, Ursa or Clinkz can be a minor threat for Phantom Assassin early in the game, and may even be completely dominated by her thanks to her evasion.

* Cleave heroes will clear her illusions. Such heroes include Sven, Magnus, Dragon Knight in Elder Dragon Form, Ember Spirit (via item), Phantom Assassin (via talent or item), etc.

* Both Hex and Mana Drain destroys Naga Siren's illusions in an instant, making it hard to teamfight or push against a team with Lion. If Lion chooses the AoE effect talent for Hex or the multi-target Mana Drain, it can negate her pushing potential entirely.
* Earth Spike is an AoE disable with good damage. If used well, it can help distinguish the true Naga Siren by the damage they take (illusions take more damage).

* Finger of Death's burst damage can kill him due to his low health pool, and Ethereal Blade only makes it worse. If Lion purchased an Aghanim's Scepter, the situation only grows worse.
* If Meepo ganks Lion with Poof and Earthbind, he will be an easy target for Earth Spike & AoE Hex from his level 25 talent.

* Phantom Strike allows Phantom Assassin to jump on his clones.
* Meepo's low health pool can burst down by Coup de Grace critical strike.

* Heroes with teleports to escape Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit

* Mana Drain is very effective against heroes that have mana burn abilities such as Anti-Mage, Nyx Assassin and Keeper of the Light.

* Heroes who lack escape mechanisms or disables are all easy targets for Phantom Assassin if they are not careful. Look for Luna, Venomancer and Shadow Fiend and try to catch them off guard.

* Heroes with high burst damage: Lina, Lion, Luna, Nyx Assassin, Queen of Pain.

* Heroes with high magical burst can easily kill Huskar when he is at low health: Lion, Lina, Skywrath Mage

* Carries that can out damage Huskar will do well against him: Legion Commander, Faceless Void, Troll Warlord, Phantom Assassin.

* Ancient Apparition has no escape or reliable control and is very fragile, which makes him an easy target for anyone who can get on top of him, like Phantom Assassin or Clinkz.

* Finger of Death can instantly shred many targets especially fragile Heroes like Keeper of the Light, Ancient Apparition, or Bounty Hunter.

* Lion will continuously Mana Drain Tiny, depleting his small mana pool for his abilities.
* Hex will keep Tiny from using his high damage spells and attack damage.

* Due to Tiny's non-existent agility gain, high physical damage heroes are more effective against him (Clinkz, Phantom Assassin, Templar Assassin, Ursa, Wraith King etc).

* Mana Drain is a headache for Bristleback to deal with during the laning stage, as it denies him the ability to get last hits with Quill Spray.
* Finger of Death deals high damage to Bristleback, and only triggers his passive once.

* Medusa lacks mobility or escape mechanisms. Earth Spike and Hex can neutralize her strong damage potential and allow for Lion's team to focus her down.
* In addition to easily breaking her commonly bought Linken's Sphere with its low cooldown, Mana Drain can quickly drain her Mana Shield, making her far less tanky.

* Nature's Prophet's low mobility and health pool allows Phantom Assassin to destroy him in the early game.
* Phantom Strike allows Phantom Assassin to jump in and out of Sprout, provided she has vision.

* Lion possesses two strong disables in Earth Spike and Hex and heavy magic burst with Finger of Death which help lock him down and prevent him from escaping with Activate Fire Remnant. When getting his Blink Dagger Lion can punish Ember Spirit's overextension immediately, or initiate a fight on him with disables.
Additional:
* Ember lacks any protection against Lion's disables early in the game and often does not acquire any later, allowing Lion to Hex or Earth Spike him before he escapes through his Fire Remnant.
* Although Flame Guard can prevent magic damage, it does not stop Lion's disables, and Lion can usually break through it with Finger of Death.

* Phantom Strike allows Phantom Assassin jump directly to Io.
* Coup de Grace makes short work of Io's low health and armor.

* Phantom Strike allows her to jump on Sniper with increased attack speed.
* Coup de Grace and Desolator shreds Sniper's low health and armor.
* Blur can be activated to get within Phantom Strike's range, surprising Sniper before he has a chance to react. Its passive also reduces Sniper's overall effectiveness against Phantom Assassin, provided he hasn't purchased a Monkey King Bar.
Additional:
* Sniper's lack of mobility and reliance on attack range makes him an easy target for Phantom Assassin to jump on.

* Phantom Assassin can easily escape Lich's slows with Phantom Strike.
* Phantom Assassin's Coup De Grace can be used to burst down the squishy Lich.

* With a lot of disables with good range, he might cancel your Echo Stomp.
* Mana Drain can be used to drain Elder Titan's already low mana pool.

* Although Weaver can potentially Time Lapse out of any burst, Weaver has a fragile health pool, and Lion's disables can kill him before.
* Weaver is very mana dependent and has a rather small mana pool in the beginning of the game. Mana Drain can deplete him of mana and lessen his early game presence.
* Earth Spike can be point targeted and hits through Shukuchi to make him vulnerable.
* Linken's Sphere is easily broken by targeted spells with low cooldown.

* Blur allows Phantom Assassin to escape from Lone Druid and the spirit bear. Additionally, it provides evasion which effectively reduce the damage output from the Spirit Bear and reduce the chances to root her, forcing him to invest in Monkey King Bar
* At late game, Phantom Assassin out carry Lone Druid.

* Hex and Earth Spike can hold Clinkz down, giving him no chance to use Black King Bar or Skeleton Walk.
* Finger of Death quickly kills Clinkz due to his low health.

* Assuming they have not bought anti-evasion items, attack dependent heroes such as Viper, Ursa or Clinkz can be a minor threat for Phantom Assassin early in the game, and may even be completely dominated by her thanks to her evasion.

* Wraith King has a very low mana pool and depends on it to cast Reincarnation. Mana Drain will render him useless.
* Wraith King has very low mobility, making it easy for Lion to disable and harass him.
Additional:
* While not being able to confront Wraith King by himself, Lion's Mana Drain helps in draining Wraith King's mana, preventing him from reincarnating unless he has his Aghanim's Shard.
* Lion's Earth Spike and Hex provide decent lockdown against Wraith King as well, preventing the latter from benefiting from Vampiric Aura bonuses.

* Blink Strike does not grant Riki a mobility advantage over Phantom Assassin, as her Phantom Strike serves the same purpose, but with a higher range.
* A Carry Riki usually has a hard time dealing with Blur, as a Monkey King Bar or Bloodthorn are unfavourable item picks for him (or, even more unlikely, a Silver Edge).
* A Black King Bar is a very common pick for Phantom Assassin, fully countering Smoke Screen and Diffusal Blade while activated.

* Blur makes it hard for Monkey King to stack Jingu Mastery.
* Phantom Strike allows Phantom Assassin to blink directly to Monkey King during Wukong's Command, bypassing all his clones.
* Coup de Grace's high damage can kill Monkey King quickly, thus ending Wukong's Command prematurely.

* Heroes with nukes: Bane, Lich, Lion, Skywrath Mage

Additional:
* Enchantress is very fragile without any form of magic resistance, allowing Lion to easily burst her down.
* Nature's Attendants is a slow heal, making it ineffective against Lion's burst.
* Enchantress lacks any escape mechanism apart from her raw movement speed, allowing Lion to disable her.
* Since Lion's damage comes mostly from his skills, Untouchable does nothing to mitigate it.

* Death Ward's first target (before it bounces) can evade it, therefore Windranger and Phantom Assassin are poor choices to use it on.
* However, once the first hit landed, the bounces can no longer miss. Don't forget to manually aim for a target with no evasion !

* In general, heroes such as Lion, Silencer, Skywrath Mage, Sven, Ogre Magi and others with reliable disables are crucial to killing Techies before they can suicide.

* High priority targets like Queen of Pain, Drow Ranger and even Anti-Mage can't get caught out from Lion's long range disables.

* Heroes with good mobility to avoid Jakiro's abilities and with good chase to punish Jakiro from pushing a tower: Bloodseeker, Ember Spirit, Juggernaut, Phantom Assassin, Weaver.

* All assassin-type carries in a one against one situation: Meepo, Phantom Assassin, Riki, Ursa.

* Any heroes with stuns or silences: Death Prophet, Lion, Shadow Shaman, Skywrath Mage

* Crystal Maiden's low health pool and slow movement speed make her a tempting and easy target.
* However, it may be wise to build Black King Bar first before attempting to fight her alone, as she can disable you and retaliate with Freezing Field.

* Lion's disables are also really effective against channeling Heroes, like Enigma or Crystal Maiden.

* Heroes who lack escape mechanisms or disables are all easy targets for Phantom Assassin if they are not careful. Look for Luna, Venomancer and Shadow Fiend and try to catch them off guard.

* Heroes with high burst damage and Black King Bar can take down Dark Willow quickly: Phantom Assassin, Sven, Wraith King

* Finger of Death can instantly shred many targets especially fragile Heroes like Keeper of the Light, Ancient Apparition, or Bounty Hunter.

* All of Lion's abilities are active making Demonic Purge break from Aghanim's Scepter useless.
* Hex and Mana Drain can make quick work of whatever illusions you're creating, especially when he acquires his Talents at level 20 and 25.
* An attempt to save an ally using Disruption can easily become a perfect setup for a Earth Spike or Finger of Death with Aghanim's Scepter for the enemy.

* Hex's instant cast time will force Brewmaster into the awkward situation of needing some form of spell immunity or block to prevent being immediately hex upon blinking in, or wait until Lion has used all his crowd control before entering a fight. His direct magic burst also makes Brewmaster's Drunken Brawler worthless versus Lion.

* Mana Drain depletes Nercophos' mana pool, preventing him from using his abilities.
* Finger of Death deals high magical damage, which becomes amplified by Ghost Shroud.

* Phantom Assassin doesn't care about Silencer's spells as she relies on right-clicks more than spells.
* Phantom Assassin often builds Black King Bar, which allows her to remove Global Silence before engaging.

* Blur is a real problem for Lycan, while she deals critical hits.

* Heroes that can drain mana negatively affect Viper's ability to use Poison Attack, Nethertoxin and Viper Strike: Lion, Anti-Mage

* Assuming they have not bought anti-evasion items, attack dependent heroes such as Viper, Ursa or Clinkz can be a minor threat for Phantom Assassin early in the game, and may even be completely dominated by her thanks to her evasion.

* One of Lion's level 20 talents lets Mana Drain affect 2 secondary targets. This can make things difficult for heroes like Phantom Lancer, Chaos Knight, and Terrorblade who rely on illusion armies.
* Mana Drain and Hex instantly kill any illusions. Finger of Death upgraded with Aghanim's Scepter also shreds most illusions.
* One of Lion's level 20 talents lets Mana Drain affect 2 secondary targets. This can make things difficult for heroes like Phantom Lancer, Chaos Knight, and Terrorblade who rely on illusion armies.

* Hex and Mana Drain can be used to immediately destroy Spectre's illusion when she Haunts. A fast fingered Lion can protect himself and a teammate.
* Hex and Earth Spike are good lockdown spells to control and kill Spectre, especially if she doesn't buy defensive items like Linken's Sphere and Black King Bar.
* Finger of Death can be used to burst down Spectre when she is low on life as she has very poor magic resistance.

* Fragile support heroes are all ideal targets for the Phantom Assassin. Heroes such as Lina and Witch Doctor are all prime targets that may not be able to react quickly and fight back due to Phantom Assassin's sudden appearance.

* 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.

* Heroes with high magical burst damage will kill Gyrocopter before he gets to do much: Lina, Lion, Zeus

* One of Lion's level 20 talents lets Mana Drain affect 2 secondary targets. This can make things difficult for heroes like Phantom Lancer, Chaos Knight, and Terrorblade who rely on illusion armies.
* Mana Drain and Hex instantly kill any illusions. Finger of Death upgraded with Aghanim's Scepter also shreds most illusions.
* One of Lion's level 20 talents lets Mana Drain affect 2 secondary targets. This can make things difficult for heroes like Phantom Lancer, Chaos Knight, and Terrorblade who rely on illusion armies.

* Heroes with long or multiple disables will prevent Legion Commander from winning Duels: Shadow Shaman, Lion

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

* Heroes that can kill Death Prophet with nukes can prevent her from using Exorcism to its full duration or using it at all: Lina, Lion, Puck, Morphling.

* Hex greatly reduces Timbersaw's mobility.
* In addition, Lion can follow up with his Earth Spike and Mana Drain combo, preventing Timbersaw to escape with Timber Chain. And he can finish Timbersaw off with Finger of Death if the latter's HP is low enough.

* Mana Drain has an extremely long range and low cooldown. It can easily deplete most heroes of their entire mana pools, especially those with smaller mana pools such as Tiny or Spirit Breaker.

* One of Lion's level 20 talents lets Mana Drain affect 2 secondary targets. This can make things difficult for heroes like Phantom Lancer, Chaos Knight, and Terrorblade who rely on illusion armies.
* Mana Drain and Hex instantly kill any illusions. Finger of Death upgraded with Aghanim's Scepter also shreds most illusions.
* One of Lion's level 20 talents lets Mana Drain affect 2 secondary targets. This can make things difficult for heroes like Phantom Lancer, Chaos Knight, and Terrorblade who rely on illusion armies.

Additional:
* Mana Drain is a real problem to Chaos Knight early game, considering his already low mana pool.
* Aghanim's Scepter upgraded Finger of Death is an AoE ability, which can deal a tremendous amount of damage to his illusions.

* Lion's disables are also really effective against channeling Heroes, like Enigma or Crystal Maiden.