* Sanity's Eclipse does massive damage to Wraith King who naturally has a low mana pool and typically doesn't build items to increase it.
* Wraithfire Blast's slow projectile speed makes it easy to avoid using Astral Imprisonment.

* Heroes with single-target abilities will be overwhelmed by Lycan and his summons: Wraith King, Bane, Phantom Assassin.

* Mirana's Leap is ineffective if Lycan uses Shapeshift. It also allows him to dodge Sacred Arrow.
* As a natural Necronomicon carrier, he can reveal Mirana and her allies hiding in Moonlight Shadow and the Necronomicon Warrior can kill Mirana from an unintentional Sacred Arrow or Starstorm upgraded with Aghanim's Scepter.

* Heroes that can protect or dispel stunned allies such as Legion Commander, Outworld Destroyer, Shadow Demon and Oracle can reduce the effectiveness of Sacred Arrow.

* Ursa struggles against heroes with strong (and especially undispellable) disables (Disruptor, Puck, Shadow Demon, Outworld Destroyer and etc).

* Lycan's ultimate makes him immune to slows from Ursa's Earthshock as well as allowing him to outmaneuver Ursa during Enrage. Lycan can also easily chase down Ursa while shapeshifted, should Ursa try to flee.

* Heroes with pure damage can kill Huskar when he inevitably gets low on health: Outworld Destroyer, Silencer.

Additional:
* Outworld Devourer can dodge Life Break with Astral Imprisonment, leaving him unharmed while Huskar loses HP.
* Sanity's Eclipse can deal massive damage to Huskar before he builds up his Berserker's Blood stacks due to Huskar's low mana pool.

* Heroes with low armor and little mobility, like Huskar, Io, etc. will also have an unfortunate fate.

* Arcane Orb deals heavy damage to both Lone Druid and the Spirit Bear.
* Astral Imprisonment can prevent the Spirit Bear from attacking, which is Lone Druid's main damage output.
* Sanity's Eclipse deals heavy damage to Lone Druid.

* 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.

* Arcane Orb deals pure damage against the real Terrorblade, bypassing his high base armor.
* Arcane Orb and Sanity's Eclipse will make very short work of Terrorblade and his illusions.

* Arcane Orb and Sanity's Eclipse quickly drains Pudge's limited mana pool, making him unable to use Meat Hook or Dismember and also bypasses Flesh Heap.
* Outworld Destroyer can save allies or himself caught by Dismember or Meat Hook with Astral Imprisonment.

* The movement speed granted from Shapeshift means that Spectre has no way to punish Lycan if he wants to splitpush or pick off supports. Furthermore, he will kite Haunt and cannot be slowed by Spectral Dagger.
* As Lycan typically has Summon Wolves out and builds Necronomicon, very rarely will he be damaged by Desolate if he does manage to get into a fight against her.
* Lycan is often part of an early game push strategy which is often the best counter to Spectre because she needs a lot of time and space to come online as a late game carry.

* Arcane Orb's pure damage ignores Mars' Bulwark.
* Astral Imprisonment can be used to stop Mars from being disruptive or save allies from his abilities.
* Sanity's Eclipse deals high damage to Mars, due to his low intelligence.

* Astral Imprisonment is a versatile nuisance:
* If it is cast on a low-enough-health unit at least 1 second into Shallow Grave's duration, the Shallow Grave will end during the imprisonment, and the target will take lethal damage when released.
* It can be used remove Dazzle from the fight at a time he could have saved someone.
* It lets himself or an ally dodge all of Poison Touch's effects, for long enough to recover their Blink Dagger.

* Lycan doesn't care much about Lich's slows thanks to Shapeshift.
* Chain Frost can bounce to the wolves that Lycan summons.
Additional:
* Lich possesses a lot of slows, which Lycan doesn't care about when he Shapeshifts.
* Lich has no in-built escape, which makes him a good target for Lycan.

* Shapeshift allows Lycan to chase down Earth Spirit.

* Arcane Orb's pure damage goes through Counterspell, and deals splash damage to illusions spawned from Manta Style.
* Sanity's Eclipse hits Anti-Mage while he is disabled with Astral Imprisonment, and forces him to take heavy damage due to his low intelligence.
* Essence Flux keeps Outworld Destroyer at high mana, thus greatly reducing the damage from Mana Void.
Additional:
* Counterspell doesn't work versus Arcane Orb because it does pure damage.
* Anti-Mage cannot burn all of Outworld Devourer's mana without disables due to Essence Flux.
* Anti-Mage's Manta Style illusions are quickly destroyed by Arcane Orb.
* However, if the enemy has multiple means of removing mana, Mana Void becomes a threat to Outworld Devourer, Anti-Mage has better mobility than Outworld Devourer with Blink, and Counterspell blocks a large portion of the damage from Sanity's Eclipse.

* Shapeshift allows Lycan to escape from Upheaval with 650 movement speed.
* Warlock doesn't have a lot of AoE abilities to deal with Lycan's wolves from Summon Wolves.

* Astral Imprisonment can be used to protect allies by imprisoning either them or Spirit Breaker.
* Arcane Orb will heavily drain Spirit Breaker's intelligence, rendering him almost useless and unable to cast spells. Spirit Breaker's low intelligence also means Sanity's Eclipse will deal a lot of damage to him.

* Arcane Orb 's pure damage can do great damage to Underlord.
* Sanity's Eclipse can tear down Underlord's health by a large amount, since his mana pool is very low compare to OD's high mana pool.

* Astral Imprisonment wastes Borrowed Time's duration.
* Outworld Destroyer's Sanity's Eclipse can kill Abaddon before Borrowed Time triggers.

* Outworld Destroyer's pure damage from Arcane Orb is very effective at killing Troll Warlord quickly.
* Astral Imprisonment removes Troll Warlord from a fight for four seconds, minimizing his contribution to a teamfight, and potentially wasting over half of Battle Trance's duration.
* Troll Warlord gains a measly 1 intelligence point per level, meaning Sanity's Eclipse is especially effective, often instantly killing him.

* Shapeshift increases Lycan's movement speed and renders him unslowable, allowing him to easily avoid and escape Ancient Apparition's abilities.
* Lycan has many fast summons, both his wolves from Summon Wolves and from the frequently built Necronomicon, all of which can do heavy damage to Ancient Apparition due to his immobility and low armor.

* Magnetic Field is useless against melee heroes, so Lycan can attack Arc Warden without missing.
* Flux doesn't affect Lycan that much, because Shapeshift grants immunity to slows and because he is never alone.
* If their Tempest Double has been called, Lycan can still kill Arc Warden before the double expires.

* Outworld Destroyer doesn't care if Razor steals his damage because he does most of his damage through Arcane Orb.
* Astral Imprisonment can prevent Razor from using the stolen damage from Static Link or chasing with Eye of the Storm.
* Sanity's Eclipse will do a ton of damage to Razor due to his low mana pool.

* Zeus can deal a huge amount of damage, but he lacks defensive abilities, such as good mobility or resistance. Due to that, he doesn't like to be touched by any means. Heroes with higher damage output and good mobility will often get easily near Zeus and trade damage (eventually causing Zeus's downfall). Such Heroes include: Lycan, Slark, Storm Spirit, Spectre and others.

* Shadow Demon, Outworld Destroyer and Tusk can all save a Lasso'd teammate with their defensive spells.

* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, Pugna, Nature's Prophet, Dark Seer, Lycan, Tusk

* Lycan and Weaver has abilities that allow them to move at maximum movement speed, and those abilities can't be dispelled, potentially wasting the slow from Demonic Purge.
* You can potentially kill a fragile Weaver by using disruption during Shukuchi with a well-placed Sentry Ward, wasting the Shukuchi. But odds are he'll wait to get low health, Time Lapse the damage away and Shukuchi away once more.

* Heroes with summons like Broodmother,Enigma, Invoker, Nature's Prophet, Lycan, Visage;or illusions, like Naga Siren, Phantom Lancer, Terrorblade are effective at keeping the choke points and rune spawns safe from Proximity mines in the early game.

Additional:
* He can send wolves to defuse Proximity Mines, and he can catch up Techies and kill him before they can deny themselves. Even if the suicide is successful, Lycan can still survive because of his tankiness.

* Heroes with mana burn: Nyx Assassin, Invoker, Outworld Destroyer, Pugna

* Heroes who possess abilities that can save targets from being killed by Reaper's Scythe: Abaddon, Bane, Outworld Destroyer, Shadow Demon, Omniknight, etc.

* Skywrath mage also has a terrible time fighting against anything that isn't a hero. As Mystic Flare only affects heroes, his skills are mostly target-based and he has terrible strength and agility, he can easily be kited or harassed by illusion-based heroes like Chaos Knight and Phantom Lancer, or by Heroes that summon other units like Lone Druid, Lycan and Beastmaster.

* Heroes with low armor and little mobility, like Huskar, Io, etc. will also have an unfortunate fate.

* Every hero that can withstand or prevent Eclipse at level 7: Juggernaut, Riki, Clockwerk, Drow Ranger, Abaddon, Faceless Void, Weaver, Outworld Destroyer.

* Illusion based heroes (like Chaos Knight and Terrorblade) can't use their illusion beneficially against Sanity's Eclipse's high AoE burst damage.

* Illusion and heroes with summons are difficult to kill with Chen's single-target offensive spells: Terrorblade, Phantom Lancer, Chaos Knight, Broodmother, Naga Siren, Lycan, Visage. However, Chen can convert enemy summons with Holy Persuasion, as long as they don't bunch up.

* Heroes with single-target abilities will be overwhelmed by Lycan and his summons: Wraith King, Bane, Phantom Assassin.

* Heroes with hiding abilities can protect disabled allies: Outworld Destroyer, Shadow Demon, Tusk, Phoenix with Aghanim's Scepter

* The pure damage provided by Arcane Orb is a great addition for killing Ember Spirit.
* Astral Imprisonment fully negates all magic damage of Flame Guard and Searing Chains and will temporarily save himself from Sleight of Fist's physical damage, and Ember Spirit is not a hero that can counter these skills.

* Shapeshift allows Lycan to get close and disable Marksmanship.
* Shapeshift also makes him immune to slows like Drow Ranger's Frost Arrows.
Additional:
* The Wolves' speed causes the knockback from Gust to be ineffective.
* She lacks escapes and loses her Marksmanship when someone is near her. Lycan takes advantage of these weaknesses.

* Arcane Orb's pure damage penetrates Guardian Angel's defense.
* Outworld Destroyer's intelligence steal is also devastating to Omniknight's already low mana pool.

* Outworld Destroyer's pure and magical damage is particularly effective against Axe.
* Astral Imprisonment is an excellent way to defend against an initiating Axe.
* Sanity's Eclipse deals high damage to Axe due to his low mana pool.
Additional:
* Berserker's Call bonus armor doesn't block Arcane Orb's pure damage.
* Astral Imprisonment can be used to prevent an ally or Outworld Devourer himself from an Axe initiation.
* Axe's low mana means he's susceptible to a powerful Sanity's Eclipse.

* Arcane Orb's constant pure damage output is devastating to Dragon Knight.
* Dragon Knight's relatively low mana pool leads to heavy damage from Sanity's Eclipse, which also bypasses his armor.

* Arcane Orb deals pure damage, which ignores armor granted from permanent agility stacks.
* Astral Imprisonment can disrupt any Pounce attempt by banishing the leashed ally.
* Slark's low intelligence and therefore mana pool makes him more susceptible to Sanity's Eclipse.

* Arcane Orb deals constant pure damage, which bypasses Timbersaw's Reactive Armor.
* Sanity's Eclipse can hit targets inside Astral Imprisonment, which helps Outworld Destroyer finish off Timbersaw before he escapes with Timber Chain. It can also drain his mana, limiting his ability to escape should he survive.
Additional:
* Arcane Orb's pure damage ignores Timbersaw's Reactive Armor.
* Astral Imprisonment, if timed correctly, can interrupt Timber Chain, preventing him from escaping.

* Astral Imprisonment protects an ally for much of Rolling Thunder's duration, especially at the lower levels. As Rolling Thunder has a considerable cast animation, an Outworld Destroyer with Blink Dagger can initiate on him and destroy his timing.

* Astral Imprisonment allows Outworld Destroyer to save himself or ally from Invoker's combo, or remove Invoker from a fight temporarily.
* Arcane Orb's pure damage will deal a lot of damage against Invoker's mediocre strength gain.
* EMP is useless against Outworld Destroyer by activating Equilibrium.
* However, be aware that Sanity's Eclipse will most likely not deal any damage at all, due to Invoker's high intelligence gain compared to Outworld Destroyer's.

* A Lycan with Shapeshift can always run down Puck and kill him very quickly due to his low armor. It is important to abuse as many cliffs and trees as possible to escape from a Lycan.

* Astral Imprisonment allows Outworld Destroyer to save himself or his teamates during Omnislash.
* Juggernaut's low mana from his low intelligence gain means that he'll take a lot of damage from Sanity's Eclipse.

* Void's slow is useless against Lycan by activating Shapeshift.
* Night Stalker's single target abilities (with the exception of Void upgraded by Aghanim's Scepter) is not very effective against Lycan's Summon Wolves and Necronomicon minions during the early and mid game.

* Sanity's Eclipse will likely instantly kill all illusions.

* Heroes with single-target abilities will be overwhelmed by Lycan and his summons: Wraith King, Bane, Phantom Assassin.

* Any heroes with low mana pools will die quickly or even instantly to Sanity's Eclipse: Doom, Phantom Assassin, Troll Warlord.

* Any hero that can nullify effects of Chronosphere: (Omniknight, Keeper of the Light with Aghanim's Scepter during daytime, Winter Wyvern), banishing him or Faceless Void (Outworld Destroyer, Shadow Demon, Earth Spirit with Aghanim's Scepter) or protecting him in other ways (Dazzle, Oracle, Abaddon) can greatly limit Chronosphere's potential.

* Astral Imprisonment can allow Outworld Destroyer to save himself or allies from Kunkka's full kit.
* Sanity's Eclipse deal a large amount of damage, as Kunkka's mana pool is much smaller than Outworld Destroyer's.
* Arcane Orb deals pure damage, shredding through Kunkka and his team even with Ghostship's buff.

* Any heroes with low mana pools will die quickly or even instantly to Sanity's Eclipse: Doom, Phantom Assassin, Troll Warlord.

* Sanity's Eclipse only triggers Bristleback's passive once, and deals high damage against Bristleback's low intelligence.

* Heroes who can hide the Dueled target (Outworld Destroyer, Shadow Demon, Tusk, Phoenix with Aghanim's Scepter etc).

Additional:
* Outworld Devourer can save an ally hero caught by Duel with Astral Imprisonment, and he can inflict heavy damage on Legion Commander with Arcane Orb to aid his ally. However, if he gets caught, he is unlikely to survive the duel, due to his lack of durability.

* Heroes with summons: Lycan, Broodmother, Visage.

* Outworld Destroyer's pure and magical damage is particularly effective against Earthshaker.
* Astral Imprisonment catches Earthshaker while he blinks in, preventing him from executing his combo.
* Earthshaker has mana troubles, and Outworld Destroyer's abilities can press this by stealing intelligence comes from Arcane Orb, therefore depleting his mana pool and mana regeneration.
* Sanity's Eclipse deals high damage to Earthshaker, due to his low intelligence and mana pool.

* Shapeshift is useful for killing or escaping Silencer.
* Summon Wolves, and later Necronomicon units, can be used to hunt a badly wounded Silencer down - even when Lycan himself can't fight.

* Outworld Devourer's pure damage from Arcane Orb can go through Cold Embrace.
* Outworld Devourer can negate the healing from Cold Embrace using Astral Imprisonment, and steal mana while doing so.
* Outworld Devourer's damage during Winter's Curse is reduced due to Arcane Orb being unable to target allies.
Additional:
* Winter Wyvern must never put her allies in Cold Embrace against Outworld Destroyer as Arcane Orb will continue to steal Intelligence and deal damage to the defenseless hero.
* Arcane Orb does not hit his allies when he is taunted by Winter's Curse, making it weak against allies, but strong versus enemies.
* Astral Imprisonment can protect a target inflicted with Winter's Curse.

* Outworld Destroyer's pure damage will mop up Primal Split's units very quickly.

* 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

* Lycan is a common Necronomicon 3 carrier, hindering his attempt of initiate or escape using Vendetta.
* And the Last Will can be killed quickly with Nyx Assassin's high burst damage, although he can at least partially counter it with a well-timed Spiked Carapace.
* Lycan's high HP easily shrug off Nyx Assassin's burst damage and fend him off.