* Phantom Assassin's high physical damage is greatly reduced by Bulwark.
* God's Rebuke has true strike, ignoring the evasion from Blur.

* 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).
Additional:
* Fire Spirits applies a severe attack speed slow, severely hindering Phantom Assassin's damage output. While Phantom Strike may be able to slightly remedy the problem, Phoenix' magical and pure damage output completely ignore Blur's evasion, resulting in severe damage to her low health pool.

* Bristleback's reliance on physical damage with Quill Spray is negated by Bulwark.
* Mars can knock back Bristleback to prevent him from chasing down allies with Viscous Nasal Goo.

* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, Pudge, Bristleback, Mars.

* Heroes who can disable Mars but cannot do any damage to him, meaning he just tanks their abilities: Doom, Magnus.

* 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.

* 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.

* Heroes who lack burst damage will have a hard time against Mars: Phantom Lancer, Nature's Prophet, Lich.

* Heroes with wide AoE abilities will reveal Monkey King through Mischief: Necrophos, Phoenix, Alchemist, Earthshaker, Razor, Tinker, Leshrac, Queen of Pain

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.

* Monkey King's natural reliance on trees makes him an exceptionally prime target for Spear of Mars. Should Monkey King use Mischief to disguise himself, it will still hit him, stunning him in the process.
* God's Rebuke easily pushes Monkey King out of Wukong's Command.

* Heroes who depend on attacks (such as Shadow Fiend or Drow Ranger) can be nullified by Fire Spirits' attack speed slow.

* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Drow Ranger, Luna, Sniper, Troll Warlord, Weaver, Clinkz.

* Bulwark negates most of the physical damage from Terrorblade and his illusions.
* Mars' AoE abilities kill Terrorblade's illusions quickly.

* Spectre cannot have a good game if she is pressured heavily in lane, which is something Mars can do.
* Spectre can use Haunt and Spectral Dagger inside and outside from Arena of Blood, but it doesn't really matter since Mars does best during the early and mid game.
* Should Spectre get to the late game, Mars can block a large amount of her damage and split the teamfights in his advantage.

* Icarus Dive helps Phoenix escape the slow from Stroke of Fate's and Soulbind.
* Supernova protects Phoenix from spell damage during Soulbind.

* 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.

* 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.

* Because Duel requires both combatants to face each other, Bulwark will reduce a large portion of her damage, reducing the chances that Legion Commander will win the duel.
* Spear of Mars and God's Rebuke pushes Legion Commander away during Duels against allies.
Additional:
* Bulwark prevents Legion Commander from gaining wins with Duel.

* 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 make a safe distance before she even landed the hit.
* Sun Ray has 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.
Additional:
* 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.

* 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's large damage over time with Icarus Dive and Fire Spirits can kill Chen's allies before he can use Hand of God.
* Phoenix's Supernova is not damaged by Chen's creeps.
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.

* Shukuchi cannot help Weaver escape from Arena of Blood, so with vision, Weaver is an easy kill.
* Time Lapse will also not save Weaver in a large amount of situations inside Arena of Blood, especially if he's pinned to the walls with Spear of Mars.
* The Swarm and Geminate Attack is not very useful against a hero that can tank 70% of his main damage source.

* 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.
* Icarus Dive grants Phoenix capability to quickly escape to safety.

* 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.

* 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.

* 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.

* Heroes who can disable Mars but cannot do any damage to him, meaning he just tanks their abilities: Doom, Magnus.

* Heroes that are able to slow Tiny's attack speed, like Tusk and Phoenix, will greatly limit his Physical damage output.

* Heroes who lack burst damage will have a hard time against Mars: Phantom Lancer, Nature's Prophet, Lich.

* 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.

* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, Pudge, Bristleback, Mars.

* Heroes that can negate Hoodwink's mobility: Kunkka, Disruptor, Mars.

* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Drow Ranger, Luna, Sniper, Troll Warlord, Weaver, Clinkz.

* Heroes who lack burst damage will have a hard time against Mars: Phantom Lancer, Nature's Prophet, Lich.

* 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

* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Drow Ranger, Luna, Sniper, Troll Warlord, Weaver, Clinkz.

* 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.

* Sand King and Phoenix has many tools to deal with a crowd of Heroes, which will work well against a crowd of illusions.

* Illusion-based heroes such as Naga Siren or Chaos Knight are vulnerable to Phoenix's DPS and attack speed slow, as their illusions, no matter how many, will be unable to deal enough damage to actually be a threat, and they will all be completely useless against the Supernova.

* Heroes with the capability of removing or destroying trees greatly hinders the effectiveness of Treant Protector's abilities: Batrider, Nature's Prophet, Lina, Enigma, Mars

* Heroes who rely on their target to run away: Riki, Bounty Hunter.

* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Drow Ranger, Luna, Sniper, Troll Warlord, Weaver, Clinkz.

* 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.

* Icarus Dive quickly escapes from Shadow Demon abilities, especially Demonic Purge.
* Phoenix AoE abilities remove Shadow Demon's illusions created by Disruption.

* Bulwark blocks much of Slark's basic attack damage, even during Shadow Dance.
* Slark finds it very difficult to have a good early/mid game when pressured in the early game by Spear of Mars and God's Rebuke.
* Spear of Mars and God's Rebuke can hit Slark through Shadow Dance.
* Should Pounce be on cooldown, Slark is very vulnerable inside Arena of Blood.

* Supernova with or without Aghanim's Scepter allows to save ally or himself through Ice Blast.
* Icarus Dive quickly escapes from Cold Feet.
Additional:
* 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.

* Heroes that are hard to gank: Dragon Knight, Mars, Centaur Warrunner.

* Phoenix turns night to day, overriding Dark Ascension during Supernova.

* 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

* Bulwark blocks the attack from Meepo and his clones.
* Spear of Mars & God's Rebuke prevents Meepo and his clones from initiation or escaping.

* Arena Of Blood prevents Bloodseeker from attacking a Ruptured target.
* Bulwark helps Mars survive Rupture ganks simply by turning towards Bloodseeker without moving.
* Spear of Mars and God's Rebuke can push Bloodseeker from Ruptured targets.

* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Drow Ranger, Luna, Sniper, Troll Warlord, Weaver, Clinkz.

* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Drow Ranger, Luna, Sniper, Troll Warlord, Weaver, Clinkz.

* Juggernaut deals mostly physical damage, which is easily mitigated with Bulwark.
* Juggernaut's Omnislash switches to opposite directions which each slash, so Mars can mitigate most of its damage since he only takes full damage from one direction: his back.