* Though Slark's large damage output is most certainly a concern for the squishy Crystal Maiden, she does perform fairly well against him when coupled with aid from her team.
* Slark has no innate way to cancel Freezing Field, but the common purchase of Skull Basher does make Slark a substantially greater threat to Crystal Maiden as the game progresses.
* Freezing Field can still hit Slark while he is under the effect of Shadow Dance, and for the early and mid game, the damage output of Crystal Maiden's ultimate outscales Slark's passive regeneration, making a quick use of Freezing Field as soon as Slark uses Shadow Dance a great way to combat him.
* Crystal Maiden's Frostbite and Crystal Nova are helpful in disabling and slowing the slippery Slark so he can be killed by her teammates.

* 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.

* 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.

* Heroes who can slow and kite Axe will severely inhibit his presence in fights: Bristleback, Crystal Maiden, Batrider, Arc Warden, Winter Wyvern, Clockwerk

* 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.

* Heroes with mobility spells like Queen of Pain, Anti-Mage, Riki, Puck, and Spirit Breaker that are cancelled by Frostbite can suffer greatly from the presence of Crystal Maiden. It is absolutely critical, however, to have followup from teammates, as all of the above heroes can make quick work of the squishy Crystal Maiden after they are released from her grip.

* Frostbite can disarm and root Troll Warlord if he doesn't have a Black King Bar or a Manta Style to dispel it.
* Crystal Nova and Freezing Field both significantly slow Troll Warlord, making him much more vulnerable to ganks or stuns.
* The magical damage from Freezing Field does a large amount of AoE damage, and Troll Warlord is not capable of cancelling Crystal Maiden's channel.

* 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.

* 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.

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

* 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.

* 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.

* 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.

* 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.

* 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.

* Heroes with mobility spells like Queen of Pain, Anti-Mage, Riki, Puck, and Spirit Breaker that are cancelled by Frostbite can suffer greatly from the presence of Crystal Maiden. It is absolutely critical, however, to have followup from teammates, as all of the above heroes can make quick work of the squishy Crystal Maiden after they are released from her grip.

* 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.

* Heroes with powerful rooting abilities will disable most of Pangolier's skill, a bonus point if it pierce spell immunity since it will also be able to stop Pangolier during his Rolling Thunder: Treant Protector, Meepo, Crystal Maiden, Dark Willow, Underlord, Naga Siren

* 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.

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

* 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.

* 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.

* Frostbite kills boars instantly on the laning stage leading to either experience lead or disabling Beastmaster from using Boar
* Crystal Nova nukes and slows down the attack and movement speed of Beastmaster's summons.
* Freezing Field grants improved self armor, nukes and slows down Beastmaster and his summons.

* 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.

* Though certainly not a "hard counter", Crystal Maiden's skillset (magical damage nukes) does pose a substantial threat to Phantom Assassin through the mid game, especially if followed up with engagement by her team.
* A quick use of Freezing Field directly after Phantom Strike can leave Phantom Assassin trapped inside the area of effect, capitalizing on Phantom Assassin's relatively low HP pool when she is not protected by Blur.
* If Phantom Assassin chooses not to buy a Black King Bar relatively early, the attack slow from Freezing Field can greatly hinder the proc chance of Coup de Grace in a teamfight.
* However, Phantom Assassin's massive damage, and her tendency to build both Black King Bar and Skull Basher makes her a formidable foe the later the game goes, and fighting her without a team is almost never a good choice.

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

* Heroes like Enchantress and Chen, or heroes that make use of Helm of the Dominator are weak to Crystal Maiden, as Frostbite can do wonders against Enchant, Holy Persuasion, or dominated creeps. Careful though, as an army of carefully controlled creeps (Enchantress and Chen) can hold many stuns that will cancel Freezing Field.

Additional:
* Frostbite does 1000 magical damage to Enchantress's creeps and roots them for 10 seconds, which hinders her ability to gank.

* Heroes with mobility spells like Queen of Pain, Anti-Mage, Riki, Puck, and Spirit Breaker that are cancelled by Frostbite can suffer greatly from the presence of Crystal Maiden. It is absolutely critical, however, to have followup from teammates, as all of the above heroes can make quick work of the squishy Crystal Maiden after they are released from her grip.

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

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

* Frostbite will reveal invisible heroes for its duration, making it a good tool against any such hero (Riki, Bounty Hunter, Weaver, or Clinkz for example), or as a soft counter to Shadow Blade, if it is used first. This can be an amazing tool to ensure that Dust of Appearance is used on the unit in question, and not wasted in not catching anything.

* Heroes the make heavy use of illusions, like Chaos Knight, Phantom Lancer, or Spectre can suffer from Crystal Maiden, as Freezing Field can quickly kill off the entire horde if not stopped.

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

* Heroes the make heavy use of illusions, like Chaos Knight, Phantom Lancer, or Spectre can suffer from Crystal Maiden, as Freezing Field can quickly kill off the entire horde if not stopped.

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

* Heroes like Enchantress and Chen, or heroes that make use of Helm of the Dominator are weak to Crystal Maiden, as Frostbite can do wonders against Enchant, Holy Persuasion, or dominated creeps. Careful though, as an army of carefully controlled creeps (Enchantress and Chen) can hold many stuns that will cancel Freezing Field.

Additional:
* Frostbite instantly kills your creeps.
* Crystal Maiden has a lot of AOE dmg between Crystal Nova and Freezing Field to clear your creeps out side and during team fights.

* 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 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.

* 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.

* 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.

* 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.

* Tanky melee heroes that can easily be kited, which allows Outworld Devourer to deal heavy damage with Arcane Orb from a distance: Sven, Underlord, Bristleback.

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

* 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.

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

* 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.

* Frostbite will reveal invisible heroes for its duration, making it a good tool against any such hero (Riki, Bounty Hunter, Weaver, or Clinkz for example), or as a soft counter to Shadow Blade, if it is used first. This can be an amazing tool to ensure that Dust of Appearance is used on the unit in question, and not wasted in not catching anything.

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

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