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.
Phoenix
* Phoenix constantly depletes its own health due to the health costs of its abilities. Unlike heroes that have a similar mechanic, Phoenix does not benefit from low health, nor does it really have a countermeasure for it. As such, Phoenix is a very vulnerable target for Necrophos to prey on, especially when caught off guard before it can cast 
Supernova.
Additional:
* Necrophos becomes a bigger threat the lower one's health gets, and unfortunately for Phoenix, most of its spells have noticeable health costs. Those costs, coupled with his Heartstopper Aura, means that staying in a teamfight for too long under Necrophos' presence will make Phoenix a more valid target for his ultimate, with its stun completely preventing any form of retaliation or protection. Necrophos players are also likely to buy more durability items such as 
Hood of Defiance, making him more able to withstand Phoenix's damage despite having no escape mechanisms.
* However, it is also important to remember that a Scepter-upgraded Supernova can help protect an ally from his ultimate.
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.
Phoenix
* Heroes with spell immunity-granting spells will render Phoenix useless against them, as Phoenix has almost no spell immunity-piercing ability, other than the stun at the end of Supernova: 
Lifestealer, 
Juggernaut.
Doom
* Heroes with low mana pools (eg.
Doom and
Tidehunter) will feel the effects of Silencer's Intelligence Steal far more than others.
Phoenix
* Silencer will most likely disrupt an initiation with his ultimate, 
Global Silence, prevent escape with his 
Last Word, and if Phoenix happens to die to him (or near him) enough times, he would sap enough of Phoenix's much needed Intelligence to make him a stronger foe and Phoenix with less mana than it already had.
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
* 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.
Doom
* Doom generally does not impede Sven in almost any way, provided he has activated God's Strength beforehand.
Phoenix
* Phoenix expends health to use its abilities, making it a good target for Thirst.
* Rupture deals heavy damage against 
Icarus Dive.
Additional:
* Although 
Blood Rite can be easily avoided, if it does hit, its lengthy silence and pure damage can be a severe punishment for a slow, unobservant, or simply unfortunate Phoenix.
* His 
Rupture can turn Icarus Dive into a suicide option, and it cannot be dispelled, meaning even if Phoenix completes a Supernova, choosing to Dive may just cut its health back down.
* And finally, due to Phoenix's health costs, too much careless ability spamming may just put Phoenix into Bloodseeker's vision through 
Thirst, making it a very tempting ganking target.
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.
Phoenix
* Marci can destroy Supernova by herself with Unleash at any stage of the game.
* Phoenix is squishy hero with low armor and is very vulnerable for Rebound and Sidekick at the laning stage.
Doom
* Doom's low armor makes him weak against Alchemist's high physical damage output.
Phoenix
* Chemical Rage kills Phoenix very quickly in Supernova.
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.
Phoenix
* Juggernaut's high attack speed lets him destroy a Supernova easily. He can even attack a Supernova during Blade Fury with his regular attacks.
* 
Blade Fury protects Juggernaut from all of Phoenix's spells (except Supernova, which pierces spell immunity).
* Blade Fury can also dispel the attack speed slow from 
Fire Spirits and the movement speed slow from Icarus Dive.
* Phoenix's Icarus Dive will not protect it from 
Omnislash unless it dives into creeps, and Phoenix's low armor makes for an easy kill.
Phoenix
* As a hero with uncommon traits, 
Phoenix's abilities require more health than mana. It is advised for Rubick to purchase health regeneration items such as 
Tranquil Boots, 
Urn of Shadows or Hood of Defiance to keep up with the HP loss.
* Phoenix's signature Supernova, if casted successfully, can turn a teamfight around if being stolen.
* The initial lift and the following crowd control from the drop of 
Telekinesis can protect the egg from being attacked if casted right before Supernova with quick fingers.
* A successfully reborn Supernova refreshes the cooldown of Telekinesis as well as 
Fade Bolt, so don't hesitate to spam both of them before Supernova with the reasons mentioned above.
* Supernova has a stun range of 1200, which requires Rubick to have Level 3 
Arcane Supremacy at least to exceed its range. Consider buying 
Aether Lens or 
Blink Dagger to help with positioning.
* It is not possible to cast Supernova (as of 7.31c) with 
Aghanim's Shard's extra 
Sun Ray even with both spell stolen, since Sun Ray takes up two stolen ability slots.
* Icarus Dive is a useful repositioning ability for scouting, initiation or escaping.
* Fire Spirits aids with Rubick farming given enough HP regeneration. In early skirmishes, the stolen ability can slow the attack speed of the enemy team to a crawl.
* Combined with Fade Bolt, both the attack damage and attack speed of the enemy team are reduced if they have no source of dispel, effectively nullifying their physical attack damage.
* Sun Ray thrives in and after a teamfight by damaging enemy heroes and healing allies at the same time.
* Rubick can interrupt both Icarus Dive and Sun Ray by casting Telekinesis.
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.
* Sniper is largely a right-click hero, and as such isn't as an effective of a Doom target as other heroes.
* Thanks to 
Shrapnel and 
Headshot, Sniper is able to effectively 'kite' Doom, preventing him from closing the distance between the two.
Phoenix
* 
Lil' Shredder will make quick work of Supernova.
* 
Mortimer Kisses can easily hit a Phoenix using Sun Ray.
Phoenix
* Inner Beast helps Beastmaster's team destroy Supernova quickly.
Doom
* High health heroes (
Axe, Doom) fall fast with Fury Swipes stacks.
Phoenix
* Ursa can easily unleash a number of attacks in an incredibly short amount of time, easily destroying the Supernova in a couple of seconds regardless of Fire Spirits' debuff. His 
Enrage also dampens any damage Phoenix might toss at his direction, as well as remove any debuffs Phoenix may place on him.
Doom
* Doom makes Ursa less disruptive, and it cannot be dispelled with Enrage upgraded with 
Aghanim's Scepter.
Doom
* Heroes with a slow attack rate will find themselves struggling to take out Tombstone, like Doom.
Phoenix
* Any hero with high attack speed will be a threat to Phoenix when it initiates, as they can easily tear down a Supernova, perhaps even while debuffed by Fire Spirits: Juggernaut, 
Clinkz, 
Troll Warlord, 
Beastmaster, 
Lina.
Phoenix
* Silence (and mana burns) will be a persistent problem for Phoenix, as it is heavily reliant on its abilities whether defensively or offensively, so heroes like 
Death Prophet, 
Skywrath Mage, and even 
Nyx Assassin must be closely observed to prevent being shut down by these heroes.
* Hexes are a greater threat to Phoenix as they also disable items, preventing Phoenix from dispelling the debuff on its own.
Doom
* Heroes who often build Linken's Sphere: 
Weaver, 
Morphling, 
Medusa.
Phoenix
* Any hero with high attack speed will be a threat to Phoenix when it initiates, as they can easily tear down a Supernova, perhaps even while debuffed by Fire Spirits: Juggernaut, Clinkz, Troll Warlord, Beastmaster, Lina.
Additional:
* Due to Fervor and Battle Trance, Troll Warlord is one of the best heroes to deal with Supernova.
Doom
* 
Terrorblade can use 
Sunder to save his allies who are Doomed.
Doom
* Heroes who often build Linken's Sphere: Weaver, Morphling, Medusa.
Phoenix
* Phoenix does significant magic damage over time which can either be dispelled or negated by Fate's Edict.
* Oracle's burst damage potential can prove lethal to Phoenix, as they already have to sacrifice health to cast their basic skills.
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.
Phoenix
* 
Void can interrupt Icarus Dive.
* His 
Crippling Fear's silence will shutdown a spell caster Phoenix.
* However, Phoenix punishes Night Stalker with Supernova because it will turn night into day, and it has a higher priority than 
Dark Ascension, effectively canceling the passive bonuses Night Stalker gets from 
Hunter in the Night.
Phoenix
* Phoenix turns night to day, overriding Dark Ascension during Supernova.
Phoenix
* Earthbind can prevent Phoenix from using Icarus Dive, the only escaping mechanism of this hero.
* Heavy burst damage from Poof can easily kill Phoenix even when it slows down all the Meepos with Fire Spirits.
* Meepo's clones destroy the Phoenix Sun from Supernova in no time, even when they are slowed down by Fire Spirits.
* Meepo's naturally high magic resistance gives Phoenix a hard time with bursting him down. He can even turn the tide if Icarus Dive is on cooldown.
Additional:
* Meepo is unlike any other multi-unit enemy Phoenix may face in the battlefield. Unlike illusion-based heroes like 
Phantom Lancer or 
Chaos Knight, Meepo's clones are not illusions, meaning they can deal full damage to the Phoenix Sun if all four (or five) are present.
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.
Phoenix
* Phoenix's limit AoE, damage-over-time abilities give Io plenty of time to save allies with Relocate.
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
* 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.
Phoenix
* Heroes who depend on attacks (such as 
Shadow Fiend or 
Drow Ranger) can be nullified by Fire Spirits' attack speed slow.
Phoenix
* Huskar's high attack speed can counteract Fire Spirits, and easily destroy the Supernova.
Additional:
* 
Berserker's Blood will let Huskar easily face down a Supernova with increased attack speed.
* Icarus Dive may not be an easy escape from Huskar either as he can chase Phoenix during it with 
Life Break if Huskar times it right.
* However, Phoenix can buy items which can
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.
Phoenix
* 
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.
* Phoenix cannot use Icarus Dive for escaping when rooted by 
Ensnare.
* However, Phoenix has many area-of-effect abilities that allow him to clear Naga Siren's illusions from 
Mirror Image.
Phoenix
* 
Sand King and Phoenix have many tools to deal with multiple enemies at once, which will work well against a crowd of illusions.
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.
Phoenix
* Phoenix's large damage over time with Icarus Dive and Fire Spirits can kill Chen's allies before he can use Hand of God.
* Phoenix naturally buys 
Spirit Vessel, which allows him to reduce healing from 
Divine Favor and Hand of God.
* Phoenix's Supernova cannot be damaged by Chen's creeps, and their normal speed means they will often not be able to kill Phoenix whenever he uses Supernova.
Additional:
* Not only Phoenix is able to disrupt Chen's jungling with Fire Spirits, but its high damage over time can also force Chen to use Hand of God prematurely, potentially wasting any chance to save his allies during teamfights.
* Creeps' damage and attack speed are very abysmal, so Chen often cannot kill Phoenix whenever it casts Supernova.
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.
Phoenix
* Fire Spirits does damage over time, preventing Faceless Void from backtracking the full damage with Time Walk.
* Fire Spirits applies a big attack speed slow, stopping Faceless Void from doing many attacks while in Chronosphere.
* Sun Ray can heal allies and damage Faceless Void from outside Chronosphere.
* Supernova can be cast outside of Chronosphere, forcing Faceless Void to step away from it, lest he'll take a lot of damage
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.
Phoenix
* Sun Ray allows Phoenix to heal any allies caught in Berserker's Call while burning away Axe's high HP at the same time.
* Icarus Dive and Fire Spirits puts Axe's Blink Dagger on cooldown.
* Axe's slow attack speed makes it difficult for him to destroy Supernova on his own.
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.
Phoenix
* Phoenix's Supernova cannot be damaged by Familiars.
* In the early and mid game, Sun Ray won't deal enough damage to be reduced by Gravekeeper's Cloak.
* Once Sun Ray deals enough damage to protect Visage, a layer of Gravekeeper's Cloak is burnt every 0.2 seconds.
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
Phoenix
* Her 
Refraction charges can and will be easily burned away by Phoenix's damage over time abilities, and 
Meld can't protect her from Phoenix's AoE abilities, even without detection.
Additional:
* Phoenix's abilities target and deals damage over time, making them a threat against Meld and Refraction. His abilities' nature makes them pretty hard to correctly land on the target, but that is not a problem against a Templar Assassin that needs to stand still during Meld.
* Icarus Dive allows Phoenix to shrug off the slow from her trap and make an easy escape from her ambush.
* As Templar Assassin relies on her quality-over-quantity bursting attacks to make quick work on fragile target, Fire Spirits' attack speed reduction can cripple her ability to deals any damage during combat. With the debuff applied in early-mid game, a Meld-breaking hit from her is significantly slowed to the point that her target can travel a safe distance before she even lands the hit.
* Sun Ray has a quick damage tick and will burn through her Refraction in no time.
* Supernova deals damage over time in an incredibly large area, and again with her quality-over-quantity style, she may not be able to attack quickly enough to break through the Phoenix Sun by herself. (not to mention the debuff from Fire Spirits) This can lead to a failed ganking attempt or even a turnaround.
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.
Phoenix
* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, 
Pudge, 
Bristleback, 
Mars.
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.
Phoenix
* Heroes with slow movement speeds and small health pools (supports like 
Crystal Maiden or Witch Doctor) are easy targets for Phoenix. Should they be inflicted by its DOT debuffs, they will be very quickly killed without even getting a chance to fight back.
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.
Phoenix
* Heroes who depend on attacks (such as Shadow Fiend or Drow Ranger) can be nullified by Fire Spirits' attack speed slow.
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.
Phoenix
* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, Pudge, Bristleback, Mars.
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.
Phoenix
* Fire Spirits applies a severe attack speed slow, severely hindering Phantom Assassin's damage output.
* Phantom Assassin cannot cast Phantom Strike on Phoenix during Supernova.
Additional:
* While her 
Phantom Strike does give limited extra attack speed, she cannot use the ability against the Phoenix Sun, and while her 
Blur may protect her from attacks, Phoenix's strong magical DPS burns away her small health pool quickly, and the attack speed slow makes her unable to fight back (provided she has no source of spell immunity).
Doom
* 
Silencer's Global Silence and Doom's Doom makes Earthshaker temporarily useless.
Phoenix
* Supernova allows Phoenix to save himself (or an ally, with Aghanim's Scepter) through 
Echo Slam. Earthshaker will also have a difficult time destroying the supernova, due to his low base attack time and poor agility.
* Icarus Dive can pass through Earthshaker's 
Fissure.
* Most of Phoenix's abilities disable Earthshaker's Blink Dagger for a good period of time due to the damage-over-time nature of its spells.
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.
Phoenix
* Heroes with slow movement speeds and small health pools (supports like Crystal Maiden or Witch Doctor) are easy targets for Phoenix. Should they be inflicted by its DOT debuffs, they will be very quickly killed without even getting a chance to fight back.
Phoenix
* Icarus Dive and Supernova can destroy the tree Monkey King is standing on.
* Fire Spirits reduces Monkey King's attack speed, preventing Monkey King from building up Jingu Mastery.
* Supernova can be casted next to Wukong's Command, forcing Monkey King to step away of it or to withstand its massive AOE damage
Additional:
* Icarus Dive, Sun Ray, and Supernova all destroy trees that Monkey King relies on to use his ability 
Tree Dance. If you spot him, you can quickly Icarus Dive in his direction and then follow up with Fire Spirits and Supernova. If you manage to cut the tree he is on, he will be stunned for 4 seconds and will be forced to take a lot of damage. However, most Monkey King players tend to build attack speed items to make use of their passive, 
Jingu Mastery, so a battle against a farmed Monkey King will depend on who gets the jump on the other first.
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
* 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.
Phoenix
* Phoenix will usually be on the sidelines or further back ready to use Sun Ray. Even after Magnus successfully uses Reverse Polarity and skewer Phoenix's teammates, Phoenix can usually counter-initiate using all of its abilities.
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.
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
* 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.
Phoenix
* Fire Spirits greatly reduces Slardar's already low starting attack speed (which Bash of the Deep relies on), making the laning phase very hard for him and discouraging Slardar from aggressively threatening lane kills.
* Supernova, ignoring Phoenix's lack of armor and Slardar's high damage single hits, is extremely hard for Slardar to take down on his own, especially after being hit by Fire Spirits.
* Icarus Dive is one of the longest distance escape spells in the game, and can help a good Phoenix escape from Slardar before he gets a Blink Dagger. However, the high cooldown means Phoenix is vulnerable to backstabs from any roamers after said spell is used.
* Slardar can interrupt an Icarus Dive from completing the flight with both of his stuns, however, likely leading to death if Supernova is on cooldown.
* A lot of the items a Phoenix builds throughout the game naturally counter Slardar. 
Shiva's Guard, 
Heaven's Halberd and 
Eul's Scepter of Divinity all stall Slardar's normal attacks in some way, while Spirit Vessel's percentage-based damage is good against his innate durability.
Doom
* Doom prevents Storm Spirit from using all of his abilities and items, rendering Storm Spirit useless in a fight.
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.
Phoenix
* Primal Beast is disarmed during Trample so will be unable to destroy a Supernova no matter how close it is to him.
* The same ability can also be used to save allies with the help of an Aghanim's Scepter.
* Sun Ray will do thousands of damage to Primal Beast if surviving a full channel time due to his high health scaling for the ability.
* Icarus Dive is a fantastic way to escape Primal Beast after he has used Onslaught.
* Phoenix has a naturally very high health pool making it hard for Primal Beast to deal with him with his magical damage.
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.
Phoenix
* Due to Spirit Breaker's low attack speed, Supernova is problematic for Spirit Breaker to take down, and even more so with Fire Spirits debuff applied.
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 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.
Doom
* Doom makes Ogre Magi less disruptive.
* Infernal Blade effectively negates Ogre Magi's durability.
* With Aghanim's Scepter, he can disable Multicast.
Phoenix
* Supernova negates Kunkka's combo entirely, as it can't be affected by spells while using Supernova.
* Icarus Dive also allows Phoenix to dodge Ghostship and Torrent.
Phoenix
* Icarus Dive quickly escapes from Shadow Demon abilities, especially 
Demonic Purge.
* Phoenix AoE abilities remove Shadow Demon's illusions created by 
Disruption.
Phoenix
* Clockwerk being confined in his own Power Cogs means Clockwerk is unable to quickly escape from Phoenix's Sun Ray and Supernova.
* Sun Ray will also heal the enemy Clockwerk is fighting, making it unlikely for Clockwerk to take an enemy down with him.
* For the same reasons, Phoenix also makes a powerful ally for Clockwerk when the situation is reversed.
Phoenix
* Heroes that depend on disrupting fights with ability combos or big ultimate abilities are vulnerable to the long stun of Fiend's Grip: 
Disruptor, Death Prophet, Enigma, 
Faceless Void, 
Invoker, 
Lich, 
Magnus, Mars, Medusa, 
Outworld Destroyer, Phoenix, 
Puck, Queen of Pain, Shadow Fiend, 
Treant Protector, Underlord, Winter Wyvern, Witch Doctor, 
Zeus.
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.
Phoenix
* Heroes with hiding abilities can protect disabled allies: Outworld Destroyer, 
Shadow Demon, 
Tusk, Phoenix with Aghanim's Scepter.
Phoenix
* Sand King has nothing to deal with Supernova, as none of his spells are effective.
* The damage-over-time abilities of Phoenix disable Sand King's Blink Dagger very often.
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.
Doom
* Ember Spirit cannot use his 
Activate Fire Remnant to escape while affected by Doom.
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.
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
* 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.
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.
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.
Phoenix
* Phoenix's AoE abilities can prove troublesome for Phantom Lancer.
* Fire Spirits dramatically reduces Phantom Lancer and his illusions' attack speed.
* Icarus Dive's movement speed reduction makes retreating difficult.
* Supernova burns away illusions, and is invulnerable to attacks from illusions.
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.
Phoenix
* Heroes that are able to slow Tiny's attack speed, like Tusk and Phoenix, will greatly limit his Physical damage output.
Doom
* Heroes with silences: Puck, Doom, 
Riki.
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.
Phoenix
* Phoenix with Supernova
* 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
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.
Phoenix
* Heroes who can hide the Dueled target (Outworld Destroyer, Shadow Demon, Tusk, Phoenix with Aghanim's Scepter etc).
Additional:
* Legion Commander relies on her powerful attack and her 
Duel to be effective. But if Phoenix gets the jump on her first, she can find herself severely slowed, taking heavy damage, and find herself unable to Duel a burning Supernova.
* It must be noted that 
Press the Attack will both dispel the attack slow of Fire Spirits and grant her or whoever she targets bonus attack speed. This allows her to easily destroy a Supernova if caution is not taken to prevent this from occurring. As such, it would be a better decision to simply avoid a farmed or skilled Legion Commander instead of attempting to overpower her.
* If an ally is caught by Duel, Phoenix can use Sun Ray to heal the ally and damage Legion Commander, possibly swinging the Duel in their team's favor. Or with Aghanim's Scepter, Phoenix can save an ally from dying in Duel with Supernova and cancel the Duel as well.
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.
Phoenix
* Lone druid's bear attacks on Phoenix's Supernova Egg don't increase the hit count. Given that Lone Druid's main hero often doesn't have much farm, the Supernova Egg is less likely to get killed.
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.
Phoenix
* 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.
Phoenix
* 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.
Phoenix
* Silence (and mana burns) will be a persistent problem for Phoenix, as it is heavily reliant on its abilities whether defensively or offensively, so heroes like Death Prophet, Skywrath Mage, and even Nyx Assassin must be closely observed to prevent being shut down by these heroes.
* Hexes are a greater threat to Phoenix as they also disable items, preventing Phoenix from dispelling the debuff on its own.
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.
Phoenix
* Any hero with high attack speed will be a threat to Phoenix when it initiates, as they can easily tear down a Supernova, perhaps even while debuffed by Fire Spirits: Juggernaut, Clinkz, Troll Warlord, Beastmaster, Lina.
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.
Phoenix
* Heroes that deal damage over time will also fail to bring down Abaddon and his allies, such as Huskar, 
Venomancer, or Phoenix.
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
* Heroes who can disable Mars but cannot do any damage to him, meaning he just tanks their abilities: Doom, Magnus.
Phoenix
* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, Pudge, Bristleback, Mars.
Phoenix
* Although Phoenix has many ways to disable a Blink Dagger, the high cooldown of all of its spells makes them not as reliable for this. Also, its spells cost a lot of health to use, making it easy to get nuked down.
* Waning Rift prevents Phoenix from using Supernova to refresh itself, giving Puck's team time to finish it off, or allow Puck to burst Phoenix down.
* Dream Coil prevents Phoenix from using Icarus Dive without consequences. Waning Rift and Dream Coil are also able to cancel Sun Ray, which is its main source of damage in the late game.
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
* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: 
Bane, Beastmaster, Bloodseeker, 
Clockwerk, Doom, Shadow Shaman.
Phoenix
* Heroes with strong area damage to destroy Phantasm illusions: Axe, Ember Spirit, Legion Commander, Phoenix
Phoenix
* Anti-Mage dispels Phoenix's slows with 
Manta Style.
* Anti-Mage can Blink directly next to Supernova, giving him more time to destroy the egg.
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.
Phoenix
* Heroes with blink or movement abilities, which are disabled by Pounce's leash: 
Anti-Mage, 
Earth Spirit, Faceless Void, Magnus, 
Mirana, Monkey King, Morphling, 
Pangolier, Phantom Assassin, Phoenix, Puck, Queen of Pain, Riki, Sand King, 
Spirit Breaker, 
Timbersaw, Tusk.
Doom
* Heroes with silencing abilities can be particularly deadly when Slark is trying to escape: Silencer, Death Prophet, Puck, Doom.
Phoenix
* Spiked Carapace reacts on any of the damage over time from Phoenix's abilities and can interrupt Sun Ray and Icarus Dive.
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.
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 .
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.
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.
Phoenix
* Tempest Double, Magnetic Field's attack speed bonus, and Arc Warden's high attack range will easily destroy a Phoenix using Supernova much faster than usual.
* Phoenix is very weak against pushers, especially those like Arc Warden who can kill him easily, as his skillset works best in teamfights.
Additional:
* His 
Tempest Double is not an illusion, but rather a full hero unit, which effectively reduces half of the Supernova's health. His 
Magnetic Field can tremendously boost his attack speed, allowing him to destroy Supernova in no time even when he's affected by Fire Spirits.
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
* 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.
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.
* Since Doom does not disable auto-cast abilities, Viper's
Phoenix
*
Corrosive Skin gives Viper additional resistance to Phoenix's magical damage, and since they deal damage over time, Phoenix would be constantly afflicted by his passive's own debuff, making him not an ideal target for Phoenix's harassment. Phoenix's abilities also constantly drain its own health away, becoming more vulnerable to 
Poison Attack.