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.
Doom
* 
Doom generally does not impede Sven in almost any way, provided he has activated God's Strength beforehand.
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.
Doom
* Heroes who often build 
Linken's Sphere: Weaver, 
Morphling, 
Medusa.
Doom
* Doom does not disable 
Mana Shield. As such, Doom's damage is largely mitigated by her mana shield. Additionally, Medusa is not reliant on her abilities to be effective during a teamfight, making Medusa an unproductive hero to target.
* Medusa is an ideal Linken's Sphere carrier. Should one be purchased, and without any additional disables, Doom may find that few opportunities exist to effectively lockdown, disable, and kill Medusa.
Doom
* Whenever Doom casts his ultimate, Centaur Warrunner can cast Stampede and allow the Doomed hero to run away, wasting Doom's ultimate.
Additional:
* 
Stampede can be used to free an ally from the grasp of Doom. Without any means of effective lockdown, kills can be difficult to secure when against an enemy Centaur Warrunner. Also, Centaur's tendency to have lots of health and HP regen tend to help counter Doom.
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.
Doom
* Drow Ranger can be difficult to get on top of, thanks to her 
Frost Arrows and 
Gust. With these two abilities, Drow Ranger is able to effectively 'kite' Doom and minimize his impact during team fights and laning stage.
* Much of Drow Ranger's effectiveness comes from her passive 
Marksmanship, which is not disabled by Doom.
Doom
* Due to Doom's naturally high health, strength gain and common itemization for durability, 
Heartstopper Aura is particularly effective. The health loss is also large enough that, throughout all stages of the game, the aura effectively neuters the health regeneration granted by Devour.
* Necrophos can help to keep both himself and his allies alive during Doom through his natural regeneration granted by Heartstopper Aura (which is not disabled by Doom), or in the case of an ally, through his 
Death Pulse. Additionally, Necrophos is an ideal 
Mekansm carrier. Should one be bought, kills against Necrophos' team can be difficult to secure due to the damage-over-time nature of Doom and his abilities.
* Doom typically wants to be a hero that soaks attention from the enemy team and takes the role of an initiator and disabler. As such, Doom is an ideal target for 
Reaper's Scythe, as it is likely Doom will be at the fore-front of any fight.
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.
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.
Doom
* Heroes with a slow attack rate will find themselves struggling to take out Tombstone, like 
Doom.
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.
Doom
* Heroes with low mana pools (eg.Doom and
Tidehunter) will feel the effects of Silencer's Intelligence Steal far more than others.
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.
Doom
* Heroes who can disable Mars but cannot do any damage to him, meaning he just tanks their abilities: Doom, 
Magnus.
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.
Doom
* Heroes who often build Linken's Sphere: Weaver, Morphling, Medusa.
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.
Additional:
* Fortune's End can dispel 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.
Doom
* Heroes with the ability to heal allies will not be able to heal heroes affected by Doom: 
Chen, 
Dazzle, 
Io, 
Oracle, 
Omniknight, 
Witch Doctor, 
Winter Wyvern, 
Abaddon, etc.
Doom
* Lone Druid is essentially two heroes. Dooming one over the other still leaves Lone Druid or his bear able to do their job during a fight. Additionally, Lone Druid is not hindered as much as other heroes by the silence and mute of Doom since the hero relies more on attacks than abilities.
Additional:
* Doom will be very hestitant to use Doom on the Spirit Bear, and using it on Lone Druid himself will not stop the bear from attacking him especially if True Form has already been used.
* 
Devour does not work on the Spirit Bear and pushes the lane so Lone Druid can safely farm under tower.
Doom
* Besides 
Lone Druid and 
Meepo, Doom is potentially good versus every hero since Doom will render any hero helpless for up to 16 seconds. This is particularly true for fragile heroes that heavily rely on mobility to stay alive.
Doom
* Wraith King has three passive abilities and only a single active ability, so Doom does not hinder him significantly.
* Doom expires upon death, so it is effectively removed after 
Reincarnation activates.
Additional:
* Even if he is Doomed, Wraith King can tear down Doom with physical attacks, and can still reincarnate as long as it is off-cooldown.
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.
Doom
* 
Feast deals damage and heals Lifestealer based on the target's maximum HP, which is greatly effective against naturally high HP heroes such as Doom.
* 
Rage allows Lifestealer to become spell immune to negate the magical damage of Infernal Blade and Scorched Earth.
* Doom has no effective means of escape from 
Open Wounds and 
Ghoul Frenzy. This is particularly devastating in the laning stage, where Doom may have to play a much more passive, conservative play style as a result.
Dark Seer
* Heroes with escape abilities: 
Anti-Mage Dark Seer Slark 
Storm Spirit 
Windranger Weaver can kite Lifestealer due to him having no lockdown.
Doom
* The slow applied from 
Corrosive Skin offsets the movement speed bonus granted by Scorched Earth and the tick-based damage from Infernal Blade and Doom will continually slow Doom down. This allows Viper, much like Sniper, to 'kite' Doom and keep him at a safe distance between the two. Additionally, Corrosive Skin applies an attack-speed slow which is fairly crippling to a hero such as Doom that, naturally, has a high base attack-time, poor agility gain and builds little attack-speed items.
* Since Doom does not disable auto-cast abilities, Viper's 
Poison Attack will continue to work. Doom may find it hard to close the distance between himself and Viper, and thusly difficult to effectively lockdown and continually deal damage through his abilities.
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
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.
Doom
* Doom can easily kill Chen's creeps and obtain their abilities with Devour.
* 
Scorched Earth's area-of-effect can clear multiple of Chen's creeps at once.
* Doom renders Chen completely helpless, and unable to save himself or his allies with Hand of God. Aghanim's Scepter upgraded Doom also allows Doom to cast Doom on himself and disable both, Chen and his creeps around him.
Dark Seer
* Ion Shell destroys 
Refraction's protection stacks in short time.
* Surge ignores the massive slow from 
Psionic Trap.
Doom
* Weak damage but high tick rate or persist in a long time: Slark, 
Gyrocopter, Queen of Pain, 
Shadow Shaman (
Shackles), 
Jakiro, Pugna, Doom
* 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), Jakiro, Pugna, Doom
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.
Doom
* Doom can eats Nature's Prophet's treants with Devour and gains lots of gold.
* Doom can buy 
Radiance or use his Scorched Earth to quickly wipe out a swarm of Treants.
* Doom and a ministun from 
Infernal Blade's prevents Nature's Prophet from escaping with Sprout and Teleportation.
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.
Doom
* Infernal Blade's damage is calculated by percentage of maximum health. Since Spectre is usually tanky, it will hurt her more than most normal attacks.
* Doom can take out Spectre out of a teamfight completely. When combined with the level 25 talent {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent}, it will disable both 
Desolate and 
Dispersion, taking away her extra damage and durability.
Additional:
* Infernal Blade's damage is calculated by percentage of maximum health, meaning that it will hurt Spectre more than most normal attacks, negating some of her tankiness.
* Doom can pick up several different abilities from neutral creeps using Devour, some of which can be annoying to Spectre.
* Mud Golem, Dark Troll Summoner, Harpy Stormcrafter, Satyr Mindstealer or Satyr Tormenter are good examples.
* Doom makes Spectre less disruptive. Combined with Aghanim's Scepter, it will disable Spectre passive skills, reducing her potential in teamfights.
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.
Doom
* A well-timed Doom prevents Nyx Assassin escaping with Vendetta and fighting back with 
Spiked Carapace.
* Doom's high health also allows him to easily shrug off Nyx Assassin's burst damage and fend him off.
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.
Doom
* Doom completely takes Windranger out of a team fight, a hero who relies heavily on using abilities and items to contribute in team fights.
Additional:
* Doom completely takes Windranger out of a team fight, a hero who relies heavily on using abilities and items to contribute in team fights.
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.
Doom
* Besides Lone Druid and Meepo, Doom is potentially good versus every hero since Doom will render any hero helpless for up to 16 seconds. This is particularly true for fragile heroes that heavily rely on mobility to stay alive.
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.
Doom
* Doom pierces spell immunity and can prevent Enigma from casting any spells or using items until the duration of the spell depletes, as well as cancelling a 
Black Hole.
* While Doom can be blocked by a Linken's Sphere, which is a common item on Enigma, Aghanim's Scepter upgraded Doom allows Doom to cast Doom on himself to affect enemies near him, and if Doom can combine this with Blink Dagger, he will be able to jump on Enigma while he is channeling Black Hole. Aghanim's Scepter upgraded Doom can also cancel Black Hole if any of Enigma's allies affected by Doom gets too close to him for it's duration, ignoring both, 
Black King Bar and Linken's Sphere.
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.
Doom
* Scorched Earth can be used to engage Visage while removing Gravekeeper's Cloak charges.
* Infernal Blade will deal tremendous amounts of damage over time due to Visage's high health pool.
* Doom completely nullifies Gravekeeper's Cloak and prevents Visage from casting spells.
Dark Seer
* Heroes with haste can negate Enchant's slow: Weaver, Dark Seer, Lycan, 
Centaur Warrunner.
Doom
* Doom with the {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent} talent can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, 
Enchantress, Huskar, Underlord.
Additional:
* Devour can easily eat creeps controlled by Enchant, limiting her ganking potential.
* Doom reduces the amount of healing received by Enchantress and her allies from Nature's Attendants. In addition, when Doom chooses the Doom applies Break talent, it can also disable Untouchable.
Dark Seer
* Heroes with hastes: Dark Seer, Lycan
Doom
* Heroes with silences: 
Puck, Doom, Riki.
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.
Doom
* Doom with the {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent} talent can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, Enchantress, Huskar, Underlord.
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.
Doom
* Supports with useful teamfight or contribution spells will be helpless against Doom: Dazzle, Oracle, Warlock.
Additional:
* Doom will not only prevent Warlock from casting his abilities in team fights, but also it reduces the healing from Shadow Word.
* Devour allows Doom to acquire a stun from neutral creeps, allowing him to interrupt Upheaval without having to use Doom.
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.
Doom
* Doom completely takes Mirana out of a team fight, a hero who relies heavily on using abilities and items to contribute in team fights.
Doom
* Infernal Blade deals scaling damage and is useful against high health targets such as Bristleback.
* Doom disables Bristleback's low cooldown abilities, preventing him from triggering Warpath. With his upgraded level 25 talent, it also breaks Bristleback's passive, rendering him more vulnerable.
Additional:
* Infernal Blade deals scaling damage and is useful against high HP targets such as Bristleback.
* Doom prevents Bristleback from casting his two low cooldown abilities, which then prevents him from utilizing 
Warpath.
* If Doom chooses the Level 25 talent {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent}, he can disable 
Bristleback and Warpath, taking away much of his durability and damage potential in team fights.
Doom
* Doom completely takes Invoker out of a team fight, a hero who relies heavily on using abilities and items to contribute in team fights.
Additional:
* Doom is a good way to shut down Invoker, preventing from casting spells and using items for a lengthy time, thus forcing him to invest on Linken's Sphere.
Doom
* Doom is generally tanky and has naturally high health, allowing him to survive Puck's onslaught in any stage of the game.
* His namesake ultimate Doom is one of the best solutions to counter Puck, as it will silence Puck for a lengthy duration. A Puck silenced for more than 3 seconds usually ends up dead.
* In addition, if Doom chooses the Level 25 talent Doom applies Mute, Puck will not be able to use items altogether, most especially Blink Dagger and 
Eul's Scepter of Divinity, making Doom a nightmare to deal with as Puck.
Doom
* Doom can completely shut down Dazzle through Doom, as it prevents him from casting his abilities and, by extension, gaining Bad Juju stacks.
Doom
* Doom alone can easily pick off Crystal Maiden since she is fairly fragile, even with using only basic attacks, Infernal Blade, and Scorched Earth.
* Doom prevents her from using any abilities in a fight, making her impact negligible.
* Devour allows Doom to acquire a stun, allowing him to cancel Freezing Field without having to use Doom.
Doom
* Doom prevents Storm Spirit from using all of his abilities and items, rendering Storm Spirit useless in a fight.
Doom
* Faceless Void relies on 
Time Walk for mobility and survivability but he can be prevented from utilizing it through Doom.
* Doom has a high cooldown duration for every ability except Infernal Blade, so he is not significantly affected by 
Time Dilation.
Doom
* Infernal Blade deals scaling damage and is useful against high HP targets such as Timbersaw.
* Timbersaw is extremely reliant on his abilities to be effective during a team fight - both for mobility, damage and crowd control. Timbersaw offers very little, impactful right-click damage, and thus Doom is particularly crippling against him.
* Additionally, when Doom chooses the {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent} talent, Doom disables 
Reactive Armor, which effectively removes the durability which Timbersaw is commonly known for.
Additional:
* Doom shuts down Timbersaw completely, negating his mobility and preventing him from doing any damage. It also breaks Reactive Armor's passive bonuses from Aghanim's Scepter.
* Infernal Blade can stun Timbersaw several times in a fight, potentially interrupting Timber Chain. Also it's useful since Timbersaw has high HP due to the damage scales based on max HP.
Doom
* Doom has several disable abilities to choose from jungle creeps (e.g. 
War Stomp, 
Ensnare) to deal with Shadow Fiend who lacks escape abilities.
* When Doom combines creep abilities with Scorched Earth, Infernal Blade, and Doom, Shadow Fiend most likely will die as he cannot use Shadowraze and Requiem of Souls to protect himself, and also cannot even flee by using 
Shadow Blade or Blink Dagger.
* Although Shadow Fiend has a high physical damage output, Doom has a large health pool to survive it, meaning Doom's combo with high magical damage output will shutdown Shadow Fiend first.
* Doom usually buys Radiance to improve his damage, making his nuke combo more deadly to Shadow Fiend. The blind also prevents Shadow Fiend from landing his attacks often.
Doom
* Infernal Blade deals scaling damage and is useful against high HP targets such as Tidehunter.
* Doom prevents Tidehunter from casting his 
Gush, 
Anchor Smash and 
Ravage, making him useless in team fights.
* If Doom chooses the Level 25 talent {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent}, he can also disable 
Kraken Shell, reducing his survivability.
Doom
* Doom can stop Death Prophet from casting spells, which makes her useless during team fights if she didn't cast Exorcism before the fight, and also nullifies healing from Exorcism and Spirit Syphon. Furthermore, Doom can use Scorched Earth to chase after her.
Doom
* Doom is effective against every hero, and Void Spirit is no exception. Being unable to cast spells or items during fights for 16 seconds nullifies his impact entirely.
* Doom has a very versatile build and can consume creeps which has abilities that can stun or provide additional magic resistance.
* Doom's high strength gain and versatility in items can be effective against Void Spirit's magical damage.
Doom
* Doom makes Ogre Magi less disruptive.
* Infernal Blade effectively negates Ogre Magi's durability.
* With Aghanim's Scepter, he can disable Multicast.
Doom
* Both Infernal Blade and Doom can be used to disable Bane while he is channeling Fiend's Grip.
* A similar effect can be achieved by using Devour on {U:Centaur Conqueror}, which will give him access to War Stomp.
Doom
* Scorched Earth deals damage to Clinkz during Skeleton Walk.
* Doom shuts down Clinkz entirely, as it prevents him from casting any of his spells and contributing a large amount of damage in teamfights.
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.
Doom
* Infernal Blade's damage is calculated by a percentage of maximum health, meaning that it will hurt Axe more than most normal attacks, negating some of his durability.
* Doom can pick up several different abilities from neutral creeps using Devour, some of which can be annoying to Axe.
* Mud Golem, Dark Troll Summoner, Harpy Stormcrafter, Satyr Mindstealer or Satyr Tormenter are good examples.
* Doom's naturally low attack speed makes Counter Helix less likely to proc, and his high base health allows him to take a few Helixes with no danger.
* Doom makes Axe less disruptive, preventing him from using his skills or items. At level 25, there is a branch of the talent tree that makes Doom apply Break, allowing Doom to disable Counter Helix, making Axe effectively useless for a lengthy duration.
Additional:
* Infernal Blade deals scaling damage and is useful against high HP targets such as Axe.
* Doom has low attack speed because of his high Base-Attack-Time, poor agility gain and limited attack-speed granting items which are commonly built. This means Doom will trigger 
Counter Helix less often and thus is an unideal target for initiation.
* Doom has naturally high HP so it takes longer for Doom to be brought down to the killing threshold of 
Culling Blade.
* Axe is highly reliant on his abilities and items to be effective during a fight. Without the usage of 
Berserker's Call and Blink Dagger due to Doom, Axe offers very little in the way of damage, effectively removing him from a fight.
Doom
* Infernal Blade deals scaling damage and is useful against high HP targets such as Elder Titan. It also can interrupt 
Echo Stomp if quick enough.
* Doom has very low base armor and naturally high HP, so he isn't significantly affected by 
Natural Order.
Dark Seer
* 
Living Armor can be destroyed quickly with Ion Shell.
Doom
* Arc Warden relies on items and abilities, as well as his 
Tempest Double, to deal damage to enemies. Doom effectively denies that and makes Arc Warden useless in fights.
Doom
* Doom applies a basic dispel upon cast, so it can remove 
Guardian Angel.
* Casting Doom on Omniknight will also prevent him from healing allies with 
Purification, or casting buffs like 
Repel and Guardian Angel, basically turning him into a harmless creep.
Additional:
* Doom turns Omniknight into a walking creep, or completely takes out his buffed cores, also removing Heavenly Grace and Guardian Angel in the process.
* With Devour used on Satyr Banisher, Doom will have access to Satyr Banisher's 
Purge, which will allow him to remove Heavenly Grace and Guardian Angel.
Doom
* Doom will make Abaddon unable to use Mist Coil, Aphotic Shield, and the active component of Borrowed Time, also upgraded with Aghanim's Scepter can break Curse of Avernus and the passive component of Borrowed Time ,which means his allies could be easily disabled or killed.
Doom
* Tinker is heavily dependent on his abilities and Doom prevents him from using any of them.
* This becomes even worse if Doom chooses the level 25 talent {ValueColor:1|Doom applies Mute|25tal} {Symbol:Talent}, which will prevent Tinker from using items such as Blink Dagger.
Additional:
* Tinker is heavily reliant on casting his spells and Doom can disable all of his abilities and items. An Aghanim's Scepter only makes it harder for Tinker to survive.
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
* 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.
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.
Doom
* Doom with the {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent} talent can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, Enchantress, Huskar, Underlord.
Doom
* Heroes that can keep Luna locked down for a long time can be a threat (she is very item and spell dependent): 
Faceless Void, Legion Commander, Doom.
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.
Doom
* Heroes with silencing abilities can be particularly deadly when Slark is trying to escape: 
Silencer, 
Death Prophet, Puck, Doom.
Dark Seer
* Dark Seer can increase the movement speed of allies with Surge, breaking Static Link.
Doom
* Heroes with the ability to heal allies will not be able to heal heroes affected by Doom: Chen, Dazzle, Io, Oracle, Omniknight, Witch Doctor, Winter Wyvern, Abaddon, etc.
Doom
* Heroes with the ability to heal allies will not be able to heal heroes affected by Doom: Chen, Dazzle, Io, Oracle, Omniknight, Witch Doctor, Winter Wyvern, Abaddon, etc.
Doom
* Silencer's 
Global Silence and Doom's Doom makes Earthshaker temporarily useless.
Dark Seer
* The haste provided by Dark Seer's Surge or a {Rune:Haste} renders Lich's slows ineffective.
Doom
* Heroes with the ability to heal allies will not be able to heal heroes affected by Doom: Chen, Dazzle, Io, Oracle, Omniknight, Witch Doctor, Winter Wyvern, Abaddon, etc.
Doom
* Terrorblade can use 
Sunder to save his allies who are Doomed.
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.
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.
Doom
* Infernal Blade deals high damage to Pudge due to his scaling health and strength gain from 
Flesh Heap.
* Using Doom with timing against Pudge who had just activated 
Rot would usually kill him.
Additional:
* Doom disables the toggling of Rot and, if cast at the right time, may leave Pudge with a potentially lethal health drain.
* Doom's naturally high health, strength gain and damage output makes him a poor target for Pudge.
* The damage of Doom's Infernal Blade scales with the target's maximum health, which is particularly effective against Pudge due to his naturally high health and further health granted by stacks of Flesh Heap.
Doom
* High health heroes (
Axe, Doom) fall fast with Fury Swipes stacks.
Doom
* Doom makes Ursa less disruptive, and it cannot be dispelled with Enrage upgraded with Aghanim's Scepter.
Doom
* Phantom Lancer's illusions can make it difficult to Doom the real hero. Should Doom figure out the real hero, the illusions can make it difficult to cast any abilities, as their hitboxes can be used to body-block the real Phantom Lancer.
* Phantom Lancer is an ideal 
Diffusal Blade carrier. With it, he can quite easily deplete Doom's already poor mana pool, potentially making him unable to cast his abilities to escape, retaliate or heal.
* Doom lacks any effective ability to clear waves of creeps and illusions, as the vast majority of his abilities are single-target. Without an answer, Doom may find it difficult to deal with Phantom Lancer's presence.
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.
Doom
* Doom's Doom marks Phantom Lancer with a highly visible effect, and also silences and mutes him.
* 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.
Doom
* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: 
Bane, Beastmaster, Bloodseeker, 
Clockwerk, Doom, Shadow Shaman.
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
* 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.
Doom
* Doom shuts down Anti-Mage's escape capabilities with Blink. The ability also deals pure damage, which ignores the protection from Counterspell.
* However, a well-timed Counterspell can reflect it back.
* If Doom has Aghanim's Scepter, Doom can break Mana Break and Counterspell, weakening both his offense and defense.
* Doom's low mana pool causes him to take little damage from Mana Void.
Additional:
* Doom prevents Anti-Mage from maneuvering around a fight or escaping from an initiation using 
Blink. Additionally, Doom deals pure damage, which is not affected by 
Counterspell. This can quickly whittle away Anti-Mage's naturally poor health pool.
* However, Doom must be careful when using Doom as a well-timed Counterspell can block and reflect it back against Doom himself.
* The Level 25 talent {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent} will also disable Mana Break and Counterspell's passive component, which makes Anti-Mage significantly less effective in fights and more susceptible to the high magical damage of Doom's abilities and his allies.
Doom
* Doom's low armor makes him weak against Alchemist's high physical damage output.
Doom
* Doom can disable 
Chemical Rage's increased healing, rendering Alchemist helpless against Doom.
* Attacks from Infernal Blade can deal serious damage to Alchemist as it deals damage based on the hero's maximum health.
Doom
* Any heroes with low mana pools will die quickly or even instantly to Sanity's Eclipse: Doom, Phantom Assassin, 
Troll Warlord.
Doom
* Any heroes with silences can negate the majority of Outworld Destroyer's damage output: Death Prophet, 
Night Stalker, 
Drow Ranger, Doom .
Dark Seer
* 
Flame Guard makes Dark Seer not deal any damage with his skills to Ember Spirit.
Doom
* Ember Spirit cannot use his 
Activate Fire Remnant to escape while affected by Doom.
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.
Doom
* 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.
Doom
* Doom with the {ValueColor:1|Doom applies Break|25tal} {Symbol:Talent} talent can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, Enchantress, Huskar, Underlord.
Additional:
* Infernal Blade does damage based on percentage health, and is useful against high health pool hero like Underlord.
* Doom can prevent Underlord from spamming his abilities and most important is to prevent him from using Fiend's Gate to escape.
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.
Doom
* Due to the nature of the hero, Sniper is typically situated in the back of the fight, potentially making him a difficult target to initiate on and fight.
Shrapnel and 
Headshot, Sniper is able to effectively 'kite' Doom, preventing him from closing the distance between the two.
* Sniper is largely a right-click hero, and as such isn't as an effective of a Doom target as other heroes.
* Thanks to