* 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.

* Naga Siren is a natural split-pusher. With Rip Tide, she will easily out-push Nature's Prophet, farming his treants in the process.
* Ensnare prevents Teleportation. Even if he hides inside Sprout, Song of the Siren lasts long enough to prevent him from escaping.
Additional:
* Naga Siren is a natural split-pusher. With a Radiance equipped, she will easily keep the lanes pushed out, therefore keeping backdoor protection enabled and preventing Nature's Prophet from dealing building damage.
* Ensnare prevents Teleportation.
* Song of the Siren will stop Nature's Prophet from escaping even if he has hidden inside of Sprout.

* 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.

* Mirror Image can dispel Frostbite.
* Song of the Siren can stop Freezing Field regardless of any kind of invisibility as well as allow Naga Siren's team to quickly close the gap on Crystal Maiden.
* With Aghanim's Scepter, Naga Siren can get access to Reel In ability, which can allow her to pull Crystal Maiden toward herself and her team and cancel Freezing Field even through Black King Bar.
Additional:
* Mirror Image can dispel Frostbite.
* Song of the Siren can stop Freezing Field regardless of any kind of invisibility as well as allow Naga Siren's team to quickly close the gap on Crystal Maiden.
* Ensnare allows Naga Siren and her team to quickly catch up with Crystal Maiden and kill her.
* With Aghanim's Scepter, Naga Siren can get access to Reel In ability , which can allow her to pull Crystal Maiden toward herself and her team and cancel Freezing Field even through Black King Bar.

* 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.

* Naga Siren's illusions from Mirror Image can depush the lanes pushed by the Tempest Double, relieving the pressure.
* Mirror Image can dispel Flux, and the illusions can stop Flux from working to it's full power.
Additional:
* Song of the Siren stops Arc Warden from acting and allows Naga Siren's team to close in on him, past his Magnetic Field.
* Mirror Image dispels Flux. The illusions created from it also disable the slow from Flux if Arc Warden casts it after Mirror Image.
* Arc Warden's playstyle heavily favors split-pushing, which Naga Siren can compete against with her illusions.

* 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.

* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.

* Doom prevents Storm Spirit from using all of his abilities and items, rendering Storm Spirit useless in a fight.

* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.

* A well-timed Doom prevents Nyx Assassin escaping with Vendetta and does not allow him to disengage with Spiked Carapace.
* Doom's high health also allows him to easily shrug off Nyx Assassin's burst damage and fend him off.

* Nyx Assassin's skillset is mostly single-targeted, therefore he will have difficulties against heroes with illusions and summons: Naga Siren, Broodmother, Lycan, Visage, Phantom Lancer.

* An Aghanim's Scepter upgraded Doom can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, Enchantress, Huskar, Underlord.

* Mirror Image can cause Huskar to Life Break the wrong target.
* Rip Tide reduces Huskar's already low armor.
* Song of the Siren allows teams to recover from Huskar's initiation, as well as the damage over time from Burning Spears.

* Tinker is heavily dependent on active abilities and Doom prevents him from using any of them.
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.

* Illusion heroes, such as Naga Siren, Phantom Lancer, Chaos Knight, Terrorblade will become strong against Tinker in the late game when Tinker's only area of effect damage, March of the Machines, ceases to kill illusions quickly. Without Aghanim's Scepter Tinker is forced to defensively disarm heroes with Laser, leaving illusions free to deal physical damage which Tinker's low armor makes highly effective. In addition, Mjollnir or Battle Fury, two common pickups against illusion heroes, don't work well on Tinker at all.

* 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.

* Song of the Siren completely wastes Abaddon Borrowed Time while keeping him in place.
* Naga Siren is able to simply dispel Abaddon's Curse of Avernus with Mirror Image before getting hit 4 times consecutively.
* Although Naga Siren's illusions can be easily destroyed by Aphotic Shield, Naga Siren can resolve that issue easily by purchasing Heart of Tarrasque to drastically increase her durability. Plus, the said item makes Naga Siren harder to be distinguished from her illusions.

* 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 Heavenly Grace 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.

* Song of the Siren will waste Guardian Angel.
* Ensnare fully works on Heavenly Graced targets. However, Ensnare is dispellable with any dispel, and so can be dispelled by Heavenly Grace.
* As an agility hero that relies on illusions, Naga Siren is one of the most natural Diffusal Blade carriers, the bane of every hero with a small mana pool.
Additional:
* Although Naga Siren relies mostly on physical damage, Song of the Siren can be used to time out Guardian Angel, giving Naga Siren's team an easy opportunity to counter-initiate.
* Radiance allows it's owner to deal magical damage to multiple enemy heroes at once, and since Naga Siren often buys it, Guardian Angel is not a very good ability for protection against Naga Siren.
* Likewise, Nuker build Naga Siren (which primarly consists of items such as Radiance, Ethereal Blade, Dagon and Veil of Discord) can render Guardian Angel useless. Although Nuker is not a role Naga Siren should be playing.

* Heroes with silencing abilities can be particularly deadly when Slark is trying to escape: Silencer, Death Prophet, Puck, Doom.

* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.

* 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 gets an Aghanim's Scepter, he can disable Bristleback and Warpath, taking away much of his durability and damage potential in team fights.

* Song of the Siren is very difficult for Rubick to Spell Steal when he is affected by sleep.
* Ensnare and Rip Tide together with some attacks can take Rubick down quickly, due to his low health pool and armor.
* Naga Siren usually buys Diffusal Blade, which may prevent Rubick from using his abilities.
* Mirror Image allows Naga Siren to dodge the incoming stun from Telekinesis (when she is not a target), and it can also dispel Fade Bolt's damage reduction debuff.

* Ensnare disables Templar Assassin's invisibility and Blink Dagger (a core item on Templar Assassin), and her illusions will break Refraction easily.

* 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 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 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 makes Ogre Magi less disruptive.
* Infernal Blade effectively negates Ogre Magi's durability.
* With Aghanim's Scepter, he can disable Multicast.

* 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 gets an Aghanim's Scepter, he can also disable Kraken Shell, reducing his survivability.

* Infernal Blade deals high damage to Pudge due to his high strength grow with 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 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.

* Infernal Blade deals scaling damage and is useful against high HP targets such as Elder Titan. It also can interupt Echo Stomp if quick enough.
* Doom has very low base armor and naturally high HP, so he isn't significantly affected by Natural Order.

* Heroes that can instantly kill creeps greatly reduce the effectiveness of Chen's converted army: Lifestealer, Doom, Mirana, Clinkz.

* Naga Siren can make landing Chen's combo very hard due to her being an illusion hero.
* Rip Tide can deal big damage to Chen and reduce Chen's armor, as well as easily kill all of Chen's creeps.
* Naga Siren often builds Radiance, which allows her to quickly clear Chen's creeps.
* Ensnare will prevent Chen from escaping.
* With Aghanim's Scepter, Naga Siren can get access to Reel In, which can separate Chen from his creeps and draw him closer to Naga Siren and her team to finish her off. To make things worse, Chen has no way to cancel Reel In on his own, and must rely on outside from {U:Centaur Conqueror} or {U:Mud Golem} under his control.
* Carry or Nuker Naga Siren can often finish off Support Chen before he can have a chance to activate Hand of God.
Additional:
* Naga Siren can make landing Chen's combo very hard due to her being an illusion hero.
* Rip Tide can deal big damage to Chen and reduce Chen's armor, as well as easily kill all of Chen's creeps.
* Naga Siren often builds Radiance, which allows her to quickly clear Chen's creeps.
* Ensnare will prevent Chen from escaping.
* With Aghanim's Scepter, Naga Siren can get access to Reel In, which can separate Chen from his creeps and draw him closer to Naga Siren and her team to finish her off. To make things worse, Chen has no way to cancel Reel In on his own, and must rely on outside from {U:Centaur Conqueror} or {U:Mud Golem} under his control.
* Carry or Nuker Naga Siren can often finish off Support Chen before he can have a chance to activate Hand of God.

* Infernal Blade's damage is calculated by percentage of max health. Since Spectre is usually tanky, it will hurt her more than most normal attacks.
* Doom can entirely disable Spectre from a teamfight. If upgraded with Aghanim's Scepter, it will disable her passive skills which is she relies on, crippling her.
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.

* Mirror Image can be effective since Night Stalker cannot withstand fighting illusions. If he's unable to tell which Naga Siren is real, he will have a hard time landing his Void. However, if Night Stalker obtains an Aghanim's Scepter, the upgraded Void will hit and may even locate the real Naga Siren in fights.
Additional:
* Ensnare and Song of the Siren prevents Night Stalker from escaping and ganking during daytime or even nighttime.
* Rip Tide reduces Night Stalker's armor, making him easier to focus down.
* Mirror Image can be effective against Night Stalker, due to his single target abilities.

* 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.

* 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.
* Be careful when using Doom as a well-timed Counterspell can block and reflect it back against Doom himself.
* An Aghanim's Scepter upgraded Doom will also disable Mana Break and Counterspell, 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 can stop Death Prophet from casting spells, which makes her useless during team fights if she didn't cast Exorcism before the fight. Furthermore, Doom can use Scorched Earth to chase after her.

* 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.

* Lycan is a hero focused entirely on single target physical damage and lacks disables or AoE damage. Due to this, he has difficulties dealing with illusions or Naga Siren's Ensnare.

* An Aghanim's Scepter upgraded Doom can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, Enchantress, Huskar, Underlord.

* An Aghanim's Scepter upgraded Doom can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, Enchantress, Huskar, Underlord.

* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.

* Heroes with illusions and summons can swarm Bane, who has no area abilities outside from Aghanim's Shard upgraded Brain Sap: Broodmother, Chaos Knight, Naga Siren, Nature's Prophet, Phantom Lancer, Terrorblade, Visage, Warlock, Wraith King.

* Naga Siren with Mirror Image
* Heroes that can dodge Glimpse:
* Puck with Phase Shift
* Riki with Tricks of the Trade
* Phantom Lancer with Doppelganger
* Ember Spirit with Sleight of Fist and Activate Fire Remnant
* Chaos Knight with Phantasm
* Naga Siren with Mirror Image
* Tusk with Snowball
* Juggernaut with Omnislash
* Brewmaster with Primal Split
* Lifestealer with Infest
* Phoenix with Supernova

* Heroes with summons like Broodmother, Enigma, Nature's Prophet; or illusions, like Naga Siren, Terrorblade are effective at keeping the choke points and rune spawns safe from Proximity Mines.

* 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.

* Heroes that create illusions: Spectre, Shadow Demon, Phantom Lancer, Naga Siren, Chaos Knight, Terrorblade) or bring other units into the fight (such as Nature's Prophet, Lone Druid, Chen, Enchantress, Meepo and Arc Warden) can cause Eclipse to strike the illusions/summons unintentionally. However, in many cases Moon Glaives can resolve this issue and eliminate them before activating Eclipse, but that will require lots of farming for right-click items.

* Illusion heroes like the aforementioned Phantom Lancer or Naga Siren, or heroes that tend to buy Manta Style, like Luna or Juggernaut, will give Slardar a hard time, as his damage is single-targeted.

* Supports with useful teamfight or contribution spells will be helpless against Doom: Dazzle, Oracle, Warlock.

* Naga Siren with Mirror Image
* Heroes that can remove the Track debuff with their skills:
* Abaddon with Aphotic Shield and Borrowed Time
* Huskar with Life Break
* Juggernaut with Blade Fury
* Legion Commander with Press the Attack
* Lifestealer with Rage and Infest
* Naga Siren with Mirror Image
* Omniknight with Heavenly Grace
* Oracle with Fortune's End and False Promise
* Phantom Lancer with Doppelganger
* Slark with Dark Pact
* Ursa with Enrage
* Weaver with Time Lapse
* Tidehunter with Kraken Shell when damage received reaches the threshold.

Additional:
* Bounty Hunter is a single target damage dealer, so he will not fare well against Naga Siren. He may try to Track her, but her Mirror Image will dispel the effect. Ensnare also reveals invisible units while they're rooted, putting Bounty Hunter at a disadvantage.

* Heroes with silences and hard stuns such as Doom, Silencer, and Lion can keep Mirana from Leaping away.

* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.

* Besides Lone Druid and Meepo, Doom is potentially good versus every hero since Doom will render any hero helpless for a prolonged 16 seconds. This is particularly true for fragile heroes that heavily rely on mobility to stay alive.

* Unless Lone Druid purchases a Black King Bar for his Spirit Bear, Ensnare will easily kite the Bear.
* Song of the Siren allows Naga Siren and her team to completely bypass the Spirit Bear and hunt for the Druid himself when starting a fight.
* Lone Druid's lack of innate AoE capabilities mean that Naga Siren's illusions have no problem against him.

* Ember Spirit cannot use his Activate Fire Remnant to escape while under effect from Doom.

* Song of the Siren does not affect Supernova, which allows her and her team to focus the egg while the enemy team is affected by sleep.

* Ensnare and Song of the Siren can be used to cancel both, Tether and Relocate and to close the distance on Io.
* Rip Tide combined with illusions from Mirror Image often finish off Io before he can save himself.
* Spirit's weak area-of-effect makes it a bad tool to deal with Naga Siren's illusions from Mirror Image.
* Once Naga Siren buys Aghanim's Scepter, she can gain access to Reel In, which not only allows her to cancel both, Tether and Relocate, but also to pull Io to herself and her team while he is affected with Ensnare, similarly to Batrider's Flaming Lasso.
* Aghanim's Shard upgraded Song of the Siren can also heal the hero Io and his tethered targed try to gank.

* Song of the Siren lasts long enough to prevent a successful Duel (but only if Naga wasn't the target).

* Doom can completely shut down Dazzle through Doom, as it prevents him from casting his abilities and, by extension, gaining Bad Juju stacks.

* Mirror Image's illusions can easily walk straight at Dazzle and attack him, due to Dazzle's lack of reliable AoE nukes or disables.
* Ensnare roots Dazzle or his allies, making it harder to stay in range of Dazzle's saving abilities.
* Song of the Siren can be used to initiate a fight with superior positioning, potentially zoning Dazzle's high-impact spells out of the fight.

* Doom makes Ursa less disruptive, and it cannot be dispelled with Enrage upgraded with Aghanim's Scepter.

* Ensnare with her attacks allows Naga Siren to gank Sniper easily.
* Rip Tide removes Sniper's very little armor.

* Heroes who can summon illusions and summons because Terrorblade has no abilities to deal with multiple enemies at once outside Reflection: Shadow Shaman, Naga Siren, Broodmother, Lycan, Enigma, Chaos Knight, Phantom Lancer, Shadow Demon, Dark Seer, Nature's Prophet, Invoker, Morphling, Visage, Grimstroke with Aghanim's Scepter.

* 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 this hero.
* Additionally, when upgraded with Aghanim's Scepter, Doom breaks 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.

* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother

* Heroes with powerful rooting abilities will disable most of Pangolier's skills, a bonus point if it pierces 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

* Heroes with silences: Puck, Doom, Riki.

* Naga Siren can easily disjoint, and dispel Corrosive Skin with Mirror Image.
* Since Viper is a single-target hero, he will not stand a chance against Naga Siren because she is an illusion based hero.

* Infernal Blade's damage is calculated by 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 effectevely 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.

* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: Sven, Omniknight, Enigma, Luna, Naga Siren, Mars, Jakiro, Venomancer, Elder Titan, Faceless Void, Rubick, Keeper of the Light, Pugna, Invoker, Spectre, Alchemist, Treant Protector, Lina, Oracle, Zeus, Shadow Shaman, Phoenix, Razor, Huskar, Batrider, Kunkka, Tidehunter, Wraith King, Sand King, Medusa, Dawnbreaker.

* An Aghanim's Scepter upgraded Doom 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 prevent him from using Dark Rift to escape

* Supports with useful teamfight or contribution spells will be helpless against Doom: Dazzle, Oracle, Warlock.

* Besides Lone Druid and Meepo, Doom is potentially good versus every hero since Doom will render any hero helpless for a prolonged 16 seconds. This is particularly true for fragile heroes that heavily rely on mobility to stay alive.