Dark Seer
* Dark Seer's strength lies in his high-mana cost skills. So 
Mana Break can be a great nuisance for him, since it can reduce his mana and prevent him from casting his spells.
* 
Mana Void can deal a lot of damage if Dark Seer spent a lot of mana on his abilities.
Ancient Apparition
* Anti-Mage can 
Blink away from Cold Feet or build a 
Manta Style to dispel it.
* 
Counterspell minimizes the damage Anti-Mage takes from all of Ancient Apparition's abilities.
* Mana Break and Mana Void deal a lot of damage to Ancient Apparition due to his high mana pool.
Additional:
* Anti-Mage easily Blinks out of 
Cold Feet's freeze radius.
* Ancient Apparition lacks mobility, thus making him fall easily to Mana Void.
* Counterspell reduces all Ancient Apparition's spell damage.
Dark Seer
* Dark Seer's only disable is Vacuum. Though he starts off with high armor and health, he'll eventually have a hard time dealing with high mobility heroes such as 
Weaver or 
Queen of Pain.
Ancient Apparition
* 
Time Lapse allows Weaver (or an ally if upgraded with 
Aghanim's Scepter) to regain HP while affected by Ice Blast.
* 
Shukuchi completely ignores the slow from Ice Vortex and helps him escape the freeze range of Cold Feet.
Additional:
* Cold Feet is extremely easy to nullify with Shukuchi.
* 
Ice Vortex does not slow Weaver in Shukuchi.
* Time Lapse will still affect his health, even when hit by 
Ice Blast.
* Ancient Apparition has no escapes or saves and is very squishy, making him an easy target for Weaver to get on top of.
Dark Seer
* Dark Seer's only disable is Vacuum. Though he starts off with high armor and health, he'll eventually have a hard time dealing with high mobility heroes such as Weaver or Queen of Pain.
Ancient Apparition
* Heroes with mobility/escape mechanisms to dodge Ancient Apparition abilites, or to easily jump on him: 
Riki, Queen of Pain, 
Phantom Assassin, 
Windranger, 
Bounty Hunter, 
Spirit Breaker, 
Night Stalker, 
Storm Spirit, 
Juggernaut, etc.
Dark Seer
* 
Flame Guard makes Dark Seer not deal any damage with his skills to Ember Spirit.
Ancient Apparition
* Lina builds 
Shadow Blade (and upgrades it into a 
Silver Edge), which makes it hard for Ancient Apparition to land his abilities.
* Laguna Blade can kill Ancient Apparition easily due to his low health pool and lack of mobility.
Dark Seer
* The constant dispel from Demonic Purge will make any attempt to save the victim or himself by 
Surge become futile. For what it's worth, Demonic Purge will also dispel 
Ion Shell.
Dark Seer
* 
X Marks the Spot prevents Dark Seer or his allies from escaping with Surge.
Ancient Apparition
* 
Dissimilate and 
Astral Step allow Void Spirit to quickly escape from Cold Feet.
* Void Spirit deals both magical and physical damage, which makes Ancient Apparition an easy target to ambush.
* If Void Spirit purchases Aghanim's Scepter, the silence provided by 
Resonant Pulse can disrupt Ancient Apparition during fights, as he is entirely reliant upon spells to contribute.
Ancient Apparition
* 
Primal Split makes Brewmaster invulnerable for the duration, rendering effects of Cold Feet and Ice Blast useless.
* 
Dispel Magic can dispel Cold Feet from allies.
* Brewmaster can easily run Ancient Apparition down with the slow from 
Thunder Clap and 
Cinder Brew.
Ancient Apparition
* 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.
Ancient Apparition
* Since Primal Beast is highly mobile with Onslaught alone, he will be difficult to catch with both Cold Feet and Ice Blast.
* Ice Blast is less effective due to Primal Beast's massive health pool and resistance to taking damage.
* While 
Chilling Touch can be used to slow Primal Beast briefly, it is not enough to beat him back, and can also contribute to his Uproar stacks.
* Primal Beast has a dispel talent at level 15 that will remove Cold Feet immediately when Uproar is used.
Dark Seer
* 
Spell Steal will easily steal all abilities from Dark Seer.
Additional:
* Spell Steal can perfect from Rubick's steal all abilities from Dark Seer. Rubick's always purchase Aghanim's Scepter can two stolens abilities from Dark Seer's and waiting for seconds for second stolen abilities (example: combinated Vacuum and Wall of Replica) and many different combination.
* A good positoning from Rubick's Spell Steal waiting steal abilities from Dark Seer 
Wall of Replica and illusion from Wall of Replica Dark Seer's can fighting with effect from outcome steal Wall of Replica from Rubick's.
* Combinated Rubick's steal Surge and 
Blink Dagger is very important catch from Dark Seer's and enemies.
* Rubick's 
Telekinesis can lifted up Dark Seer or enemy heroes and throw to Wall of Replica from Rubick's steal.
Ancient Apparition
* 
Shapeshift increases Lycan's movement speed and renders him unslowable, allowing him to easily avoid and escape Ancient Apparition's abilities.
* Lycan has fast summons, both his wolves from 
Summon Wolves can do heavy damage to Ancient Apparition due to his immobility and low armor.
Dark Seer
* A Sniper who is somewhat competent at positioning is hardly going to be affected by any of Dark Seer's spells thanks to 
Take Aim.
* However, an illusion of Sniper made with Wall of Replica is extremely powerful, and hard to deal with.
Ancient Apparition
* 
Leap allows Mirana to easily escape the freezing range of Cold Feet. Mirana also tends to build Manta Style which dispels Cold Feet.
* During 
Moonlight Shadow, the invisibility makes it hard to catch Mirana's team with Ice Blast.
* Ancient Apparition's lack of mobility/escape capabilities makes him an easy target for Mirana at any stage of the game.
Ancient Apparition
* Heroes with mobility/escape mechanisms to dodge Ancient Apparition abilites, or to easily jump on him: Riki, Queen of Pain, Phantom Assassin, Windranger, Bounty Hunter, Spirit Breaker, Night Stalker, Storm Spirit, Juggernaut, etc.
Ancient Apparition
* Lone Druid's early game is good against slow, squishy supports since his bear is very strong early game and an Entangling Claws proc almost always guarantees a kill: 
Ancient Apparition, 
Crystal Maiden, 
Shadow Shaman, etc.
Ancient Apparition
* 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.
Dark Seer
* Strong laners are usually at a disadvantage because of how well Sven can jungle. Heroes such as 
Dark Seer. 
Underlord and 
Legion Commander may find that later Sven takes care of them very quickly after some jungle farming.
Ancient Apparition
* Heroes with mobility/escape mechanisms to dodge Ancient Apparition abilites, or to easily jump on him: Riki, Queen of Pain, Phantom Assassin, Windranger, Bounty Hunter, Spirit Breaker, Night Stalker, Storm Spirit, Juggernaut, etc.
Dark Seer
* Heroes with fast movement abilities will suffer huge damage when afflicted by Rupture: Spirit Breaker, 
Earth Spirit, Dark Seer.
Additional:
* 
Rupture can deal a lot of damage to either a surged Dark Seer or his allies and prevent the target from getting into position.
Ancient Apparition
* 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.
Ancient Apparition
* 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.
Ancient Apparition
* Heroes with mobility/escape mechanisms to dodge Ancient Apparition abilites, or to easily jump on him: Riki, Queen of Pain, Phantom Assassin, Windranger, Bounty Hunter, Spirit Breaker, Night Stalker, Storm Spirit, Juggernaut, etc.
Dark Seer
* Dark Seer relies on Surge for most of his mobility, so he's not very vulnerable to slows, but much more to root effects and walls or pseudo-walls such as 
Disruptor's 
Kinetic Field or 
Slark's 
Pounce.
Ancient Apparition
* Heroes with mobility/escape mechanisms to dodge Ancient Apparition abilites, or to easily jump on him: Riki, Queen of Pain, Phantom Assassin, Windranger, Bounty Hunter, Spirit Breaker, Night Stalker, Storm Spirit, Juggernaut, etc.
Ancient Apparition
* 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.
Dark Seer
* Abilities that deal low damage with high amounts of instances are irrelevant against Pudge during Flesh Heap's active: 
Gyrocopter's 
Rocket Barrage and Dark Seer's Ion Shell are just a couple examples.
Ancient Apparition
* Heroes with mobility/escape mechanisms to dodge Ancient Apparition abilites, or to easily jump on him: Riki, Queen of Pain, Phantom Assassin, Windranger, Bounty Hunter, Spirit Breaker, Night Stalker, Storm Spirit, Juggernaut, etc.
Additional:
* Ancient Apparition's only skill to stop Storm Spirit is Cold Feet, which is bad in general when trying to stop a Storm Spirit without any other disable.
* As a fragile support with low Strength gain and no magic resistance, Ancient Apparition is vulnerable to Storm Spirit's combos.
Ancient Apparition
* 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.
Ancient Apparition
* Squishy heroes, usually supports, like Lion, Ancient Apparition, 
Keeper of the Light etc can die quickly to Tiny's magic burst.
Ancient Apparition
* 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.
Dark Seer
* In general, heroes who are melee with no way to fight back can be very easily poked by Monkey King to gain his Jingu Mastery stacks: Dark Seer, Riki, 
Rubick.
Ancient Apparition
* For the same reason, he has to be slightly more cunning when playing against heroes that can scout the treeline, such as Ancient Apparition and his Ice Vortex and 
Shadow Demon and his 
Shadow Poison.
Ancient Apparition
* 
Corrosive Skin minimizes the damage Viper takes from all of Ancient Apparition's abilities.
* Ancient Apparition's slow movement speed, squishy nature, and lack of escape abilities can easily be taken advantage of through 
Poison Attack and 
Viper Strike.
Dark Seer
* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, 
Pugna, 
Nature's Prophet, Dark Seer, 
Lycan, 
Tusk
Ancient Apparition
* 
Icarus Dive helps Phoenix escape from Cold Feet.
* However, all of Pheonix's basic abilities do cost health, which can be harmful under the effects of Ice Blast.
* 
Supernova can save Phoenix from Ice Blast.
Additional:
* Supernova with or without Aghanim's Scepter allows to save ally or himself through Ice Blast.
* Icarus Dive quickly escapes from Cold Feet.
Ancient Apparition
* Since all of Phoenix's abilities (except for Supernova) have health costs, heroes like Ancient Apparition or 
Necrophos can turn Phoenix's abilities against it. However, Supernova does completely protect Phoenix from Ice Blast.
Ancient Apparition
* As Ancient Apparition likes to stay far away from the fight to get full effectiveness from Ice Blast, he is a very good target for a 
Haunt gank.
* Ancient Apparition also has no hard disables and escape spells, making him an easy kill for Spectre.
Dark Seer
* Dark Seer can pull together Spectre's illusions with 
Vacuum, and Wall of Replica creates an illusion of Spectre that deals massive damage.
Dark Seer
* Dark Seer's Vacuum and Ion Shell can clear a wave of Chen's Creeps effectively.
* Surge applies haste movement and negates the slow from 
Penitence, allowing Dark Seer to easily escape from Chen and his creeps.
* Dark Seer's full combo from Dark Seer's Vacuum, Wall of Replica and 
Normal Punch from Aghanim's Scepter can often kill Chen or any of his allies before he can save them with 
Hand of God.
Additional:
* Dark Seer's Vacuum and Ion Shell can clear a wave of Chen's Creeps effectively.
* Surge applies haste movement and negates the slow from Penitence, allowing Dark Seer to easily escape from Chen and his creeps.
* Dark Seer's full combo from Dark Seer's Vacuum, Wall of Replica and Normal Punch from Aghanim's Scepter can often kill Chen or any of his allies before he can save them with Hand of God.
Ancient Apparition
* Ice Blast prevents 
Divine Favor and Hand of God from healing his allies or himself.
Additional:
* Ice Blast can prevent healing from Hand of God and kill Chen's creeps.
* Ancient Apparition can easily harass Chen on lane with Chilling Touch due to it's high range and damage. This can get even worse if Ancient Apparition buys Aghanim's Scepter and combines it with items that can give him bonus attack damage and attack speed.
* Chilling Touch combined with Ice Vortex makes it impossible for Chen to escape from Cold Feet. Ice Vortex can also make Chen's creeps more vulnerable to Ancient Apparition and his allies's magical damage.
Dark Seer
* Ion Shell zones out Broodmother in the laning phase, and can kill her spiderlings if used on one Spiderling in a group.
* Vacuum can pull Broodmother out of the treeline.
Additional:
* Ion Shell is a very powerful weapon against Broodmother's Spiderlings and makes her laning much harder.
Ancient Apparition
* Ice Blast prevents 
Insatiable Hunger lifesteal, 
Spin Web regeneration and quickly kills spiderlings.
Dark Seer
* Heroes that rely on summons will suffer against Ion Shell, which kills them very quickly: 
Beastmaster, 
Broodmother, 
Enigma, Nature's Prophet, 
Visage, 
Warlock, 
Wraith King.
Additional:
* Surge allows for Dark Seer and his allies to escape from Upheaval due to it ignoring any slow.
Ancient Apparition
* Ice Blast cancels Warlock's Golem's and Shadow Word's healing.
* Cold Feet stuns Warlock if he stands in place, forcing him to stop channeling Upheaval immediately or be forced to stop channeling it by it's stun.
Dark Seer
* Heroes with escape abilities: 
Anti-Mage Dark Seer Slark Storm Spirit Windranger Weaver can kite Lifestealer due to him having no lockdown.
Ancient Apparition
* Ice Blast prevents Lifestealer from lifestealing and healing with Infest in fights.
Ancient Apparition
* Ice Blast stops Morphling from gaining additional health with 
Attribute Shift.
* Using Attribute Shift would even bring Morphling closer to the shatter threshold.
* In the lane, Ice Vortex slows Morphling's already poor movement speed to a crawl; this, coupled with the amplification of magic damage, can set up an early kill on Morphling if Ancient Apparition has a suitable lane partner.
Additional:
* Ice Blast stops Attribute Shift (Strength Gain) from recovering adional health, and using it will even bring Morphling closer to the shatter threshold.
* In lane, Ice Vortex slows Morphling's already poor movement speed to a crawl; this, coupled with the amplification of magic damage, can set up an early kill on Morphling if Ancient Apparition has a suitable lane partner.
Ancient Apparition
* Snapfire is vulnerable while she is casting 
Mortimer Kisses making her an easy target for the effects of Cold Feet and Ice Blast.
Additional:
* Ice Blast, Cold Feet, and Ice Vortex are easier to land on Snapfire while she channels her Mortimer Kisses.
Ancient Apparition
* Muerta doesn't have the speed to easily escape Cold Feet, potentially controlling her during Pierce the Veil.
* Ancient Apparition outranges Muerta with Chilling Touch, allowing him to poke her down safely.
Dark Seer
* Venomancer is a low health hero and low range hero who is easy to harass with Ion Shell on a creep in the early game.
* Venomancer depends entirely on all his slows to keep distance or chase, but since Surge ignores slows, it is nearly impossible for Venomancer to hunt or run away from Dark Seer or his surged teammates.
Ancient Apparition
* 
Shallow Grave prevents Ice Blast's shatter for up to 5 seconds, but can mostly only delay it as Ice Blast's debuff lasts 10 seconds and prevents 
Shadow Wave from healing them.
Additional:
* Ice Blast negates healing from Shadow Wave, and lasts longer than Shallow Grave.
Ancient Apparition
* Cold feet can be used to ensure that the full channel of 
Freezing Field doesn't go off.
Ancient Apparition
* Ice Blast prevents Huskar from healing with 
Berserker's Blood and negates any lifesteal, making him significantly weaker in battle.
* 
Burning Spear and 
Life Break cost Huskar his own health, killing him under the effects from Ice Blast.
* Huskar often builds 
Armlet of Mordiggian which can be deadly during Ice Blast.
Additional:
* Ice Blast prevents Huskar from healing, regeneration, health gained from activating an Armlet of Mordiggian and will kill him when his health dips below a threshold. This makes it very dangerous for him to use his abilities.
Ancient Apparition
* Ice Blast completely nullifies any healing, making Necrophos unable to stay in a teamfight to sustain his teammates (and himself) or deal gradual damage to the enemy, else he be faced with a quick death if focused on.
Ancient Apparition
* Despite Ancient Apparition's fragileness, he can easily harass Luna on lane with Chilling Touch due to it's high range and damage. This can get even worse if Ancient Apparition buys Aghanim's Scepter and combines it with items that can give him bonus attack damage and attack speed.
* Chilling Touch combined with Ice Vortex can make it difficult for Luna to escape from Cold Feet
* Ice Blast can nullify any healing Luna receives and any attempt for her to save herself with 
Satanic, even through 
Black King Bar.
* For the same reasons, Ancient Apparition makes a very powerful ally for Luna when they are in the same team.
Ancient Apparition
* Ice Blast prevents Death Prophet from gaining health from 
Spirit Siphon and 
Exorcism.
Additional:
* Ice Blast prevents Death Prophet from gaining health from Spirit Siphon and Exorcism.
* However, there is a way for Death Prophet to counter Ice Blast: Since Death Prophet is not healed until the spirits are returned to her. She can attempt to outrun her spirits to delay their return until Ice Blast duration runs out.
Ancient Apparition
* Ice Blast prevents Io from healing an ally with 
Tether and prevents healing from 
Overcharge
* Io is a common 
Mekansm builder which is useless if he is affected by Ice Blast.
Additional:
* Ice Blast prevents Io from healing the target.
* Ancient Apparition can easily harass Io on lane with Chilling Touch due to it's high range and damage. This can get even worse if Ancient Apparition buys Aghanim's Scepter and combines it with items that can give him bonus attack damage and attack speed.
* Chilling Touch combined with Ice Vortex makes it nearly impossible for Io to escape from Cold Feet. Ice Vortex can also make Io and it's tethered target more vulnerable to Ancient Apparition and his allies's magical damage.
Ancient Apparition
* Ice Blast cancels out Chemical Rage's rapid health regeneration. It can also take advantage of Alchemist's Armlet of Mordiggian toggling, as it will make HP drain insanely fast, essentially killing the bearer in no time.
Additional:
* Ice Blast nullifies the health regeneration granted by 
Chemical Rage, which Alchemist greatly relies on to stay alive in battle.
* Alchemist tends to build Armlet of Mordiggian which can be deadly during Ice Blast.
Dark Seer
* Dark Seer can take great advantage of 
Divided We Stand by putting an Ion Shell on a clone in order to harass them effectively.
* Vacuum can take a single Meepo and disable him for Dark Seer and his teammates to take out.
Ancient Apparition
* 
Cold Embrace makes its target immovable, allowing Ancient Apparition to easily land Ice Blast, or a Cold Feet stun.
* Ice Blast also negates healing from Cold Embrace.
Additional:
* Ice Blast disables the healing component of Cold Embrace, making it essentially a 4 second stun on an ally and a perfect setup for Ice Blast.
* If Cold Feet is cast on an Allied hero affected by Cold Embrace, it will almost guarantee the Ally comes out stunned.
Dark Seer
* 
Living Armor can be destroyed quickly with Ion Shell.
Ancient Apparition
* Ice Blast's nullifies Abaddon healing from Borrowed Time and Mist Coil and it is not dispelled by Aphotic Shield.
Additional:
* Ice Blast nullifies 
Borrowed Time's and 
Mist Coil's healing.
Dark Seer
* Heroes that rely on summons will suffer against Ion Shell, which kills them very quickly: Beastmaster, Broodmother, Enigma, Nature's Prophet, Visage, Warlock, Wraith King.
Dark Seer
* Heroes with haste can negate Enchant's slow: Weaver, Dark Seer, Lycan, 
Centaur Warrunner.
Dark Seer
* Certain heroes can mess up with Pangolier's positioning and timing (especially if he intends to use Rolling Thunder during combat): 
Vengeful Spirit, Keeper of the Light, 
Huskar, Dark Seer
Dark Seer
* Heroes that rely on illusions typically spawn very strong illusions inside Dark Seer Wall of Replica that he can use against them or their team: 
Phantom Lancer, 
Chaos Knight, 
Naga Siren, 
Terrorblade.
Ancient Apparition
* Heroes that withstand damage like 
Timbersaw, 
Bristleback, 
Dragon Knight and others will have their durability largely reduced when hit by an Ice Blast due to the risk of shattering.
Dark Seer
* With Normal Punch from Aghanim's Scepter, Dark Seer can gain an advantage against heroes who rely on evasion as Normal Punch has true strike: Phantom Assassin, Windranger, 
Hoodwink.
Ancient Apparition
* Heroes that withstand damage like Timbersaw, Bristleback, Dragon Knight and others will have their durability largely reduced when hit by an Ice Blast due to the risk of shattering.
Additional:
* Cold Feet and Ice Vortex both hinder Dragon Knight's movement greatly during teamfights.
* Ice Blast ignores Dragon Knight's armor, disables his health regeneration, and kills him prematurely.
Dark Seer
* Heroes that rely on summons will suffer against Ion Shell, which kills them very quickly: Beastmaster, Broodmother, Enigma, Nature's Prophet, Visage, Warlock, Wraith King.
Dark Seer
* Heroes that rely on illusions typically spawn very strong illusions inside Dark Seer Wall of Replica that he can use against them or their team: Phantom Lancer, Chaos Knight, Naga Siren, Terrorblade.
Dark Seer
* Heroes with hastes: Dark Seer, Lycan
Ancient Apparition
* Heroes that withstand damage like Timbersaw, Bristleback, Dragon Knight and others will have their durability largely reduced when hit by an Ice Blast due to the risk of shattering.
Dark Seer
* Dark Seer relies on Surge for most of his mobility, so he's not very vulnerable to slows, but much more to root effects and walls or pseudo-walls such as Disruptor's Kinetic Field or Slark's Pounce.
Dark Seer
* Heroes with AoE abilities will hit Slark in Shadow Dance: 
Lina, 
Jakiro, Underlord, 
Leshrac, Dark Seer, 
Earthshaker, Timbersaw, Crystal Maiden.
Ancient Apparition
* Heroes like Slark, 
Witch Doctor and others also tend to suffer in Ice Blast's heal denial.
Additional:
* Ice Blast stops Shadow Dance's passive health regeneration, even when Slark is not in vision.
Dark Seer
* Dark Seer can increase the movement speed of allies with Surge, breaking Static Link.
Ancient Apparition
* Heroes like Slark, Witch Doctor and others also tend to suffer in Ice Blast's heal denial.
Ancient Apparition
* Ancient Apparition's Cold Feet will freeze Clockwerk in place if he stays inside his Power Cogs. His immobility while in his cogs also makes him a very easy target to Ice Vortex and Ice Blast.
Dark Seer
* Heroes that rely on summons will suffer against Ion Shell, which kills them very quickly: Beastmaster, Broodmother, Enigma, Nature's Prophet, Visage, Warlock, Wraith King.
Dark Seer
* The haste provided by Dark Seer's Surge or a {Rune:Haste} renders Lich's slows ineffective.
Ancient Apparition
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: Nature's Prophet, Ancient Apparition, 
Zeus, Invoker, 
Treant Protector
Dark Seer
* Heroes that rely on summons will suffer against Ion Shell, which kills them very quickly: Beastmaster, Broodmother, Enigma, Nature's Prophet, Visage, Warlock, Wraith King.
Dark Seer
* Heroes without blink mechanisms or spell immunity will have a hard time positioning against 
Pit of Malice: 
Sven, 
Tiny, Wraith King, Dragon Knight, 
Meepo, 
Doom, Bounty Hunter, Dark Seer, 
Undying, 
Alchemist, Legion Commander.
Dark Seer
* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: 
Luna's Aghanim's Scepter upgraded 
Eclipse, 
Dawnbreaker's 
Solar Guardian, 
Axe's 
Berserker's Call, 
Mars's 
Arena of Blood, Jakiro's 
Macropyre, 
Dual Breath and 
Ice Path, Naga Siren's 
Song of the Siren, 
Razor's 
Eye of the Storm and 
Plasma Field, Lina's 
Light Strike Array, Broodmother's 
Spinner's Snare from Aghanim's Scepter, 
Elder Titan's 
Earth Splitter and 
Echo Stomp, Alchemist's 
Unstable Concoction and 
Acid Spray, Queen of Pain's 
Sonic Wave, Dark Seer's Wall of Replica and Vacuum, 
Venomancer's 
Noxious Plague and 
Poison Nova from Aghanim's Scepter, 
Oracle's 
Fortune's End and 
Rain of Destiny from 
Aghanim's Shard, 
Bloodseeker's 
Blood Rite, Enigma's 
Black Hole and 
Midnight Pulse, 
Shadow Fiend's 
Requiem of Souls, 
Batrider's Aghanim's Scepter upgraded 
Flaming Lasso, 
Firefly, 
Flamebreak and 
Sticky Napalm, Ancient Apparition's Ice Blast, 
Sand King's 
Epicenter, 
Sand Storm and 
Burrowstrike, Gyrocopter's 
Call Down, 
Ember Spirit's 
Sleight of Fist, 
Death Prophet's Exorcism and 
Silence, 
Monkey King's 
Wukong's Command, Crystal Maiden's Freezing Field, 
Muerta's 
The Calling, 
Medusa's 
Stone Gaze, Zeus's 
Nimbus from Aghanim's Scepter. 
Dark Willow's 
Bramble Maze, 
Pangolier's 
Swashbuckle, 
Grimstroke's 
Soulbind, 
Ink Swell and 
Stroke of Fate, Earthshaker's 
Echo Slam and 
Fissure, 
Puck's 
Dream Coil and 
Waning Rift, 
Winter Wyvern's 
Winter's Curse, 
Magnus's 
Reverse Polarity.
Ancient Apparition
* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: Luna's Aghanim's Scepter upgraded Eclipse, Dawnbreaker's Solar Guardian, Axe's Berserker's Call, Mars's Arena of Blood, Jakiro's Macropyre, Dual Breath and Ice Path, Naga Siren's Song of the Siren, Razor's Eye of the Storm and Plasma Field, Lina's Light Strike Array, Broodmother's Spinner's Snare from Aghanim's Scepter, Elder Titan's Earth Splitter and Echo Stomp, Alchemist's Unstable Concoction and Acid Spray, Queen of Pain's Sonic Wave, Dark Seer's Wall of Replica and Vacuum, Venomancer's Noxious Plague and Poison Nova from Aghanim's Scepter, Oracle's Fortune's End and Rain of Destiny from Aghanim's Shard, Bloodseeker's Blood Rite, Enigma's Black Hole and Midnight Pulse, Shadow Fiend's Requiem of Souls, Batrider's Aghanim's Scepter upgraded Flaming Lasso, Firefly, Flamebreak and Sticky Napalm, Ancient Apparition's Ice Blast, Sand King's Epicenter, Sand Storm and Burrowstrike, Gyrocopter's Call Down, Ember Spirit's Sleight of Fist, Death Prophet's Exorcism and Silence, Monkey King's Wukong's Command, Crystal Maiden's Freezing Field, Muerta's The Calling, Medusa's Stone Gaze, Zeus's Nimbus from Aghanim's Scepter. Dark Willow's Bramble Maze, Pangolier's Swashbuckle, Grimstroke's Soulbind, Ink Swell and Stroke of Fate, Earthshaker's Echo Slam and Fissure, Puck's Dream Coil and Waning Rift, Winter Wyvern's Winter's Curse, Magnus's Reverse Polarity.
Dark Seer
* Heroes that rely on summons will suffer against Ion Shell, which kills them very quickly: Beastmaster, Broodmother, Enigma, Nature's Prophet, Visage, Warlock, Wraith King.
Ancient Apparition
* Heroes with large magical AoE damage will fare well against Omniknight: 
Lich, Ancient Apparition, Jakiro, Disruptor.
Ancient Apparition
* Fragile supports with low armor are always a good prey, also her Psionic Trap will wear down most attempts to flee with their built-in disables: Silencer, Crystal Maiden, Warlock, Ancient Apparition, Grimstroke, Witch Doctor
Dark Seer
* Ion Shell destroys 
Refraction's protection stacks in short time.
* Surge ignores the massive slow from 
Psionic Trap.
Ancient Apparition
* Phantom Lancer can dispel or escape from Cold Feet with 
Doppelganger and 
Phantom Rush, respectively. Phantom Lancer also frequently builds a Manta Style which dispels Cold Feet.
* Ancient Apparition has trouble dealing with Phantom Lancer's illusions due to a lack of Area of Effect damage other than Ice Blast.
* Phantom Lancer tends to build a 
Diffusal Blade, which greatly amplifies his damage against Ancient Apparition due to Ancient Apparition's high mana pool.
* Ancient Apparition has no escape/mobility mechanisms, making him an easy target for Phantom Lancer at any stage of the game.
Dark Seer
* Heroes that rely on illusions typically spawn very strong illusions inside Dark Seer Wall of Replica that he can use against them or their team: Phantom Lancer, Chaos Knight, Naga Siren, Terrorblade.
Additional:
* Ion Shell helps taking down illusions quickly, making it easy to identify the real Phantom Lancer.
* Surge allows Dark Seer and his teammates to run away from Phantom Lancer, who relies on his Phantom Rush to chase enemies.
Ancient Apparition
* Ancient Apparition's Ice Blast will only debuff Phantom Lancer and not his illusions.
* Heroes with undispellable debuffs will help identify the real Phantom Lancer through visual effects or debuff indicators, provided that it was cast on the real Phantom Lancer to begin with:
* Doom's 
Doom marks Phantom Lancer with a highly visible effect, and also silences and mutes him.
* Bloodseeker's Rupture shows a clear red trail effect on the real Phantom Lancer.
* Ancient Apparition's Ice Blast will only debuff Phantom Lancer and not his illusions.
* Grimstroke's Soulbind is undispellable.
* Shadow Demon's 
Demonic Purge is undispellable.
* Monkey King's 
Jingu Mastery is undispellable and puts a big yellow Mark over his head.
Ancient Apparition
* 
Sunder allows Terrorblade (or an ally) to regain HP while affected by Ice Blast.
* Terrorblade often buys Manta Style which can dispel Cold Feet.
Additional:
* Sunder is not affected by Ice Blast and will still swap health with any target as usual.
Dark Seer
* Dark Seer's Vacuum and Ion Shell allows him to clear a wave of Terrorblade's illusions.
* Because Terrorblade often builds items that require 
Ultimate Orb like Manta Style and 
Eye of Skadi, Dark Seer can create a very strong illusion of Terrorblade with Wall of Replica and Normal Punch from Aghanim's Scepter.
* If Dark Seer can use Vacuum to help teammates land their AoE abilities, Terrorblade will be quickly killed before he even gets a chance to use Sunder.
Additional:
* Dark Seer's Vacuum and Ion Shell allows him to clear a wave of Terrorblade's illusions.
* Because Terrorblade often builds items that require Ultimate Orb like Manta Style and Eye of Skadi, Dark Seer can create a very strong illusion of Terrorblade with Wall of Replica and Normal Punch from Aghanim's Scepter.
* If Dark Seer can use Vacuum to help teammates land their AoE abilities, Terrorblade will be quickly killed before he even gets a chance to use Sunder.
Ancient Apparition
* 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.
Dark Seer
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, 
Viper, Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom, Dawnbreaker. However, this also means they are easily stunned.
Ancient Apparition
* Heroes with mobility/escape mechanisms to dodge Ancient Apparition abilites, or to easily jump on him: Riki, Queen of Pain, Phantom Assassin, Windranger, Bounty Hunter, Spirit Breaker, Night Stalker, Storm Spirit, Juggernaut, etc.
Dark Seer
* With Normal Punch from Aghanim's Scepter, Dark Seer can gain an advantage against heroes who rely on evasion as Normal Punch has true strike: Phantom Assassin, Windranger, Hoodwink.
Ancient Apparition
* 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.
Dark Seer
* With Normal Punch from Aghanim's Scepter, Dark Seer can gain an advantage against heroes who rely on evasion as Normal Punch has true strike: Phantom Assassin, Windranger, Hoodwink.
Dark Seer
*
Fortune's End dispels Ion Shell and Surge, making any gank attempt on Dark Seer in the laning phase likely to succeed.
Fate's Edict prevents all magical damage that comes from Dark Seer's abilities. 
Fortune's End dispels Ion Shell on creeps, which Dark Seer relies on to farm and zone.
Ion Shell, a skill that helps Dark Seer immensely in the laning phase, as well as 
Surge, a move-speed buff, effectively allowing Oracle to control Dark Seer, especially in the laning phase.
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Additional:
* Fortune's End can dispel
Ancient Apparition
*
False Promise can dispel the stun from Cold Feet and can save an ally that's about to shatter from Ice Blast, even allowing healing with 
Purifying Flames by delaying it until after the debuff expires.
Purifying Flames allows Oracle to deny his allies if they're affected by Ice Blast. If he brings his allies' health to or below the shatter threshold, it will count as him denying the ally. However, this does not work on Oracle himself.
Fate's Edict provides 100% magic resistance, making it good against all of Ancient Apparition's abilities at all stages of the game.
Fortune's End can dispel Cold Feet from allies.
Ice Blast and Fate's Edict can protect an ally from the magical damage over time for a while.
Cold Feet on affected allies, preventing them from getting frozen.
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Additional:
* False Promise can prevent the shatter from
* Oracle can deny allies who are frostbitten. If he uses Purifying Flames to reach the shatter threshold, it will count as a deny.
* Fortune's End can dispel