* 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.

* Heartstopper Aura can do a decent damage overtime to Chen's High-Health-Creep Army, and Chen does not have any source of burst damage to Necrophos.
* Necrophos can purchase a Spirit Vessel to provide an AOE debuff that reduce the healing from Divine Favor and Hand of God.

* Frequent healing from Death Pulse and Mekansm/Guardian Greaves or Pipe of Insight makes it difficult for Earthshaker to execute his combo with Echo Slam.
* Necrophos usually buys Radiance to improve their burning aura damage from Heartstopper Aura will usually disable Earthshaker's Blink Dagger prior to a teamfight, preventing him from initiating or re-initiating.
* Reaper's Scythe allows to kill  Earthshaker while he blinks in, preventing him from executing his combo (although Earthshaker is rarely a primary target).

* 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.

* Ghost Shroud can be use both offensively to slow Lone Druid or Defensively to prevent Lone Druid and The Spirit Bear from attacking him.
* Heartstopper aura burns the Spirit bear High HP over time. Additionally, it can deal decent damage to Lone Druid during his True Form.

* 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.

* Reaper's Scythe will turn Tiny's high health against him.
* Heartstopper Aura does substantial damage to Tiny as a result of his high max health.

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

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

* Heartstopper Aura is effective against high health heroes, and Pudge is no exception. Coupled with his constant self-damage from Rot, being around Necrophos could prove risky for an overconfident Pudge.
* Regardless of how much health Pudge gains through Flesh Heap, Reaper's Scythe will often kill Pudge should his health fall below a certain threshold, making Necrophos an ideal counter versus Pudge.
Additional:
* No matter how high Pudge builds up strength with his Flesh Heap, all it needs is for him to fall below a certain percentage of health for him to fall to Reaper's Scythe. Considering his constant self-damage with Rot, being around Heartstopper Aura will prove risky for an overconfident Pudge.

* 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.

* Heroes with magical burst damage can often kill Phantom Assassin before she gets to do much: Necrophos, Nyx Assassin, Gyrocopter.

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

* Necrophos' largely magical damage completely ignores Bulwark.
* Ghost Shroud protects Necrophos from God's Rebuke but more importantly stops Mars from being a threat in lane.

* Heroes that have high health but little to no magic resistance are easy prey for Necrophos, as no matter how high they build their health up, Reaper's Scythe will kill them outright as long as they fall under a certain threshold, and Heartstopper Aura will deal the same amount of damage regardless, decaying their health the longer they stay within range. As such, Strength heroes like Chaos Knight, Centaur Warrunner or Magnus are good targets for his ultimate.

* 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.

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

Additional:
* Sun Ray allows Phoenix to heal any allies caught in Berserker's Call, while burning away Axe's high HP at the same time.
* Axe's slow attack speed makes it difficult for him to destroy Supernova on his own.

* Frequent healing from Death Pulse and Mekansm makes it difficult for Axe to finish off targets with Culling Blade.
* Ghost Shroud's instant cast time allows Necrophos to turn ethereal before being initiated on by Berserker's Call. This prevents him from attacking Axe while taunted, thus lowering the chance to proc Counter Helix.
* Axe's high health is relatively ineffective against Heartstopper Aura's percentage-based health degeneration.
* Reaper's Scythe negates Axe's tankiness, and can kill him quickly after initiation.
Additional:
* Frequent healing from Death Pulse makes it difficult for Axe to finish off targets with Culling Blade.
* Reaper's Scythe negates Axe's tankiness, and can kill him quickly after initiation.
* Heartstopper Aura is effective due to Axe's high strength gain.

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

* 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.

* Heroes that have small health pools and little to no escape mechanisms are even easier prey for Necrophos. Ghost Shroud's slow will allow him to catch him with them, and get nuked down with his abilities, even preventing retaliation due to Reaper's Scythe's stun. Such heroes include Crystal Maiden, Witch Doctor, Warlock or Shadow Fiend.

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

* Heroes that have small health pools and little to no escape mechanisms are even easier prey for Necrophos. Ghost Shroud's slow will allow him to catch him with them, and get nuked down with his abilities, even preventing retaliation due to Reaper's Scythe's stun. Such heroes include Crystal Maiden, Witch Doctor, Warlock or Shadow Fiend.

* 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 that have small health pools and little to no escape mechanisms are even easier prey for Necrophos. Ghost Shroud's slow will allow him to catch him with them, and get nuked down with his abilities, even preventing retaliation due to Reaper's Scythe's stun. Such heroes include Crystal Maiden, Witch Doctor, Warlock or Shadow Fiend.

* Reaper's Scythe and Heartstopper Aura deal percentage-based damage, ignoring Bristleback's high health.
* Heartstopper Aura's HP removal does not trigger Bristleback's passive.
Additional:
* Heartstopper Aura deals percentage-based damage flagged as HP removal, so it is not reduced by Bristleback, nor does it trigger passive Quill Sprays.
* Reaper's Scythe is very effective against Bristleback not only due to its percentage-based damage, but rather because it first stuns and then deals its damage, allowing Necrophos to position in front of Bristleback in time.

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

* 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.

* Reaper's Scythe can kill Terrorblade quickly before he has chance to use Sunder.
* Ghost Shroud protects Necrophos against Terrorblade's high attack damage.

* With high health and rarely buying Linken's Sphere or Black King Bar, Centaur Warrunner is a good target for Reaper's Scythe. However, Centaur Warrunner can resolve this problem by buying Pipe of Insight or Hood of Defiance to diminish its damage.
* Heartstopper Aura will do well against high health heroes such as Centaur Warrunner.

* 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.

* 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.

* Heartstopper Aura effectively negates Timbersaw's large HP pool as well as HP regen.
* Death Pulse together with health and mana regeneration from killed creeps helps Necrophos and his teammates survive Timbersaw's burst damage.
* As a tanky hero that stays in the middle of teamfights, Timbersaw is an easy target for Reaper's Scythe.

* Necrophos usually doesn't build much attack damage to steal from.
* He can use Ghost Shroud to prevent Razor from attacking him with the stolen damage from Static Link.
* Razor is somewhat vulnerable to magical damage, and Reaper's Scythe prevents him from escaping with his high movement speed when things get dangerous.

* No matter how Tidehunter builds tanky items such as (Guardian Greaves, Crimson Guard or Pipe of Insight), all it needs is for him to fall below a certain percentage of health for him to fall to Reaper's Scythe.

* 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.

* 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.

* 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.

* Necrophos is a dangerous opponent to go against with. Regardless of how many strength Undying has gained from Decay, Necrophos can finish off Undying with Reaper's Scythe once Undying's HP falls below a certain threshold.
* Heartstopper Aura will do more damage to Undying if he gained strength from Decay, as it does damage based on a hero's maximum health.

* 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.

* Death Pulse can easily wipe out Broodmother's spiderlings if they're too close while also offering Necrophos a source of regeneration for Broodmother's harass in lane.
* Ghost Shroud prevents Broodmother or her spiderlings from damaging Necrophos temporarily.
* Heartstopper Aura will regenerate lost health and mana for every spiderling or spiderite Necrophos manages to kill.

* Reaper's Scythe and Heartstopper Aura deal percentage-based damage, ignoring Underlord's high health.

* Necrophos's Reaper's Scythe can finish off a low-health Morphling.

* Heroes that have escape abilities (such as Queen of Pain, Storm Spirit or Timbersaw) can be either nullified by Reaper's Scythe or a complimentary item for Necrophos (like Rod of Atos or Scythe of Vyse). If Necrophos is quick enough and enters range, they can quickly, if not instantly, die if they are not quick enough.

* 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 can hide the Dueled target (Outworld Devourer, 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.

* Heroes that have high health but little to no magic resistance are easy prey for Necrophos, as no matter how high they build their health up, Reaper's Scythe will kill them outright as long as they fall under a certain threshold, and Heartstopper Aura will deal the same amount of damage regardless, decaying their health the longer they stay within range. As such, Strength heroes like Chaos Knight, Centaur Warrunner or Magnus are good targets for his ultimate.

* 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 that have escape abilities (such as Queen of Pain, Storm Spirit or Timbersaw) can be either nullified by Reaper's Scythe or a complimentary item for Necrophos (like Rod of Atos or Scythe of Vyse). If Necrophos is quick enough and enters range, they can quickly, if not instantly, die if they are not quick enough.

* Some heroes, such as Necrophos can be an issue if not initiated onto by Sven first.

Additional:
* His Heartstopper Aura deals the same gradual damage over time no matter how high Sven builds his strength or health pool up, and should he fall down to a certain percentage, his high health will no longer matter if Necrophos manages to land his Reaper's Scythe, killing him instantly. But it is best if Necrophos can either catch him off guard before he can possibly use his Black King Bar (which is an item Sven players commonly purchase), or bait him out of it.
* Ghost Shroud prevents Sven from hitting Necrophos, and if he doesn't have his Storm Hammer available, it could make him completely immune to Sven and allow Necrophos to easily kite him around.

* Heroes that have small health pools and little to no escape mechanisms are even easier prey for Necrophos. Ghost Shroud's slow will allow him to catch him with them, and get nuked down with his abilities, even preventing retaliation due to Reaper's Scythe's stun. Such heroes include Crystal Maiden, Witch Doctor, Warlock or Shadow Fiend.

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

* Heartstopper Aura and Reaper's Scythe go right through Dragon Knight's armor.

* Death Pulse can single out Spectre from her illusions, as well as heal his team against her. He also usually stands close to his allies for Death Pulse, effectively disabling Desolate.

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

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

* 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.

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

* Because Huskar tends to stay at low health to gain the maximum bonuses from Berserker's Blood, it makes him an exceptionally prime target for Reaper's Scythe.
Additional:
* Huskar is often at low health, making him easy prey for Reaper's Scythe.
* Ghost Shroud prevents Huskar from stacking Burning Spear, and if Heartstopper Aura stacks are active, can regenerate health lost to existing stacks.

* 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

* Reaper's Scythe can kill Alchemist before Chemical Rage has the time to heal him.
* Ghost Shroud can prevent Alchemist from attacking Necrophos, as well as make him immune to Acid Spray and Unstable Concoction damage.
* Heartstopper Aura will do damage as long as Necrophos is alive based on health percentage, which is a problem for a strength hero such as Alchemist.