Naga Siren
* 
Naga Siren's Song of the Siren may be useful but Poof will destroy all of her illusions.
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.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: 
Spirit Breaker, 
Bloodseeker, 
Witch Doctor.
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.
Naga Siren
* 
Blade Fury offers good AoE damage to clear illusions and can hurt the real Naga Siren as well if she chooses to blend in the illusions. 
Diffusal Blade does nothing to Juggernaut either when he uses Blade Fury.
* 
Aghanim's Shard upgraded Blade Fury along with Lv 20 DPS talent will shred all illusions almost instantly, especially when combined with 
Mjollnir, a common item for Juggernaut.
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.
Naga Siren
* Illusion-based heroes are effective against Omnislash and Juggernaut's single-targeted damage: Naga Siren, Chaos Knight, 
Terrorblade,Phantom Lancer.
Naga Siren
* Since Naga Siren is a hero who barely goes for 
Black King Bar, she is vulnerable to nukers with strong magical damage and big area-of-effect spells in every game more than any other carry heroes: 
Sand King, 
Jakiro, 
Leshrac, 
Lina, 
Earthshaker, 
Zeus.
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
* 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.
Naga Siren
* Zeus's abilities deal high amounts of burst magical damage, which ignores Naga Siren's high armor.
* 
Arc Lightning is a good way to destroy Naga Siren's illusions due to it's capabilities to bounce between enemies.
* 
Static Field from Aghanim's Shard can automatically hit everything in a big radius, taking a huge chunk of health out of Naga Siren's illusions, regardless of how much health they have.
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.
Naga Siren
* Jakiro's damage over time abilities can clear Naga Siren's illusions and can hurt real Naga Siren even for the duration of 
Song of the Siren.
* Naga Siren is not a hero that likes to go for Black King Bar, and that makes her very vulnerable to Jakiro's damage over time in every phase of the game.
Additional:
* Jakiro's damage over time abilities can clear Naga Siren's illusions and can hurt real Naga Siren even for the duration of Song of the Siren.
* Since Naga Siren is a hero who barely goes for Black King Bar, this can make her very vulnerable to Jakiro's damage over time in every phase of the game.
Phoenix
* Due to Fervor and Battle Trance, Troll Warlord is one of the best heroes to deal with Supernova.
Naga Siren
* 
Arcane Orb deals pure damage that can bypass Naga Siren's armor, and which can clear her illusions in no time.
* 
Astral Imprisonment can be used to prevent Naga Siren from escaping with Song of the Siren. Outworld Destroyer can also use Astral Imprisonment to protect himself from Naga Siren.
* 
Sanity's Eclipse will most likely instantly kill Naga Siren along with her illusions.
Naga Siren
* Centaur's 
Retaliate will harm all attacking enemies, which will allow Centaur Warrunner to see which is the real Naga Siren.
* A well timed 
Hoof Stomp followed by 
Double Edge will clear all Naga's illusions and prevent Naga Siren from escaping with Song of the Siren.
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.
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.
Naga Siren
* 
Flak Cannon and 
Call Down can easily clear Naga Siren's illusions.
Naga Siren
* All of Leshrac's abilities, especially 
Pulse Nova, can easily deal with Naga Siren's illusions.
* 
Aghanim's Scepter gives Leshrac access to 
Nihilism ability, that allows him to turn himself along with Naga Siren and her illusions to turn ethereal. And to make things worse, Nihilism can slow Naga Siren and her illusions, make them more vulnerable to magical damage and unable to fight back while Leshrac moves faster and does not take increased magical damage for it's duration.
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.
Phoenix
* Chemical Rage kills Phoenix very quickly in Supernova.
Naga Siren
* Dawnbreaker can easily clear waves of Naga Siren's illusions from 
Mirror Image with 
Starbreaker, 
Celestial Hammer and 
Solar Guardian.
* Aghanim's Shard upgraded Starbreaker will allow Dawnbreaker to dispel 
Ensnare and freely attack Naga Siren during Song of the Siren when combined with Black King Bar, a common item on Dawnbreaker.
* Solar Guardian allows Dawnbreaker to counter any pushing attempts of Naga Siren and rejoin her team with Solar Guardian when they require it. Aghanim's Scepter upgraded Solar Guardian can also give Dawnbreaker's allies evasion while Dawnbreaker is airborne for it's duration, as Naga Siren mainly relies on direct attacks in order to deal damage. Solar Guardian can also be used after Naga Siren uses Song of the Siren near her allies to either escape from or counter-initiate against them.
Additional:
* Dawnbreaker can easily clear waves of Naga Siren's illusions from Mirror Image with Starbreaker, Celestial Hammer and Solar Guardian.
* Aghanim's Shard upgraded Starbreaker will allow Dawnbreaker to dispel Ensnare and freely attack Naga Siren during Song of the Siren when combined with Black King Bar, a common item on Dawnbreaker.
* Solar Guardian allows Dawnbreaker to counter any attempts of Naga Siren and rejoin her team with Solar Guardian when they require it. Aghanim's Scepter upgraded Solar Guardian can also give Dawnbreaker's allies evasion while Dawnbreaker is airborne for it's duration, as Naga Siren mainly relies on direct attacks in order to deal damage.
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.
Naga Siren
* 
Waveform clear Mirror Image illusions from Naga Siren. And though Ensnare can prevent Morphling from using Waveform to escape, he can easily dispel it with Manta Style, a common item on Morphling.
* 
Morph allows Morphling to copy Naga Siren's abilities and combine them with Manta Style, a commong item for Morphling, to destroy Naga Siren's illusions. Aghanim's Scepter upgraded Morph also allows Morphling to create a strong illusion of Naga Siren that can do the same and which can also allow Morphling to close the gap on Naga Siren.
Phoenix
* Inner Beast helps Beastmaster's team destroy Supernova quickly.
Naga Siren
* Timbersaw's innate durability is very hard to deal with as Naga Siren as she mostly relies on sustained damage rather than burst damage unless if she is played as Nuker. Timbersaw's high Pure Damage and low-cooldown AoE nukes can also destroy Naga Siren's illusions very fast. Timbersaw can also build 
Lotus Orb to reflect Ensnare back at Naga SIren.
Naga Siren
* Many stacks of 
Sticky Napalm, combined with 
Flamebreak and 
Firefly, allows Batrider to destroy illusions from Mirror Image.
* If Batrider can manage to destroy all illusions from Naga Siren, he will be able to use 
Flaming Lasso on the real one, and will be able to drag her toward his team, potentially preventing Naga Siren from escaping with Song of the Siren.
Additional:
* Many stacks of Sticky Napalm, combined with Flamebreak and Firefly, allows Batrider to destroy illusions from Mirror Image.
* If Batrider can manage to destroy all illusions from Naga Siren, he will be able to use Flaming Lasso on the real one, and will be able to drag her toward his team, potentially preventing Naga Siren from escaping with Song of the Siren.
Naga Siren
* Heroes with AoE nukes will clear her illusions in no time, especially if they are percentage-damage-based, like 
Underlord's 
Firestorm, 
Elder Titan's 
Earth Splitter, 
Enigma's 
Midnight Pulse, Zeus's Arc Lightning, Jakiro's 
Liquid Frost from Aghanim's Shard etc.
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.
Naga Siren
* Heroes who are reliant on illusions or summons: Chaos Knight, 
Broodmother, Naga Siren.
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.
Naga Siren
* Illusion heroes will struggle against Primal Beast's area damage capability, such as Chaos Knight, Naga Siren, Terrorblade.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include 
Sven, 
Magnus, 
Dragon Knight, 
Luna, 
Medusa, 
Templar Assassin, 
Gyrocopter, 
Muerta.
Naga Siren
* Heroes that rely on illusions typically spawn very strong illusions inside Dark Seer Wall of Replica that he can use against them or their team: Phantom Lancer, Chaos Knight, Naga Siren, Terrorblade.
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.
Naga Siren
* 
Keeper of the Light can stall pushes with 
Illuminate. This makes him strong against pushing heroes: Terrorblade Naga siren 
Nature's Prophet and 
Anti-Mage
Naga Siren
* As long as Windranger is able to identify the real hero among the illusions, heroes relying on them can be easily tagged with Focus Fire: Chaos Knight, Terrorblade, Phantom Lancer, Naga Siren.
Naga Siren
* Heroes with AoE nukes will clear her illusions in no time, especially if they are percentage-damage-based, like Underlord's Firestorm, Elder Titan's Earth Splitter, Enigma's Midnight Pulse, Zeus's Arc Lightning, Jakiro's Liquid Frost from Aghanim's Shard etc.
Naga Siren
* Heroes with AoE nukes will clear her illusions in no time, especially if they are percentage-damage-based, like Underlord's Firestorm, Elder Titan's Earth Splitter, Enigma's Midnight Pulse, Zeus's Arc Lightning, Jakiro's Liquid Frost from Aghanim's Shard etc.
Naga Siren
* 
Lion may upgrade 
Mana Drain, 
Hex and 
Finger of Death through Talent Tree and Aghanim's itens to make them affect secondary targets or turn them into AoE abilities. This can make things difficult for heroes like Phantom Lancer, Naga Siren and Terrorblade, who rely on illusion armies.
Additional:
* Both Hex and Mana Drain destroy Naga Siren's illusions in an instant, making it hard for her to teamfight or push against a team with Lion. If Lion chooses the AoE effect talent for Hex or the shard for multi-target Mana Drain, it can negate her pushing potential entirely.
* 
Earth Spike is an AoE disable with good damage. If used well, it can help distinguish the true Naga Siren by the damage they take (illusions take more damage).
Naga Siren
* Heroes who depends on illusions and summons: Naga Siren, 
Arc Warden, Broodmother will struggle against Great Cleave.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Naga Siren
* Heroes that heavily depend on illusions or summons, (Naga Siren, Terrorblade, Phantom Lancer, 
Lycan,...) are vulnerable to Sleight of Fist and even more so if Ember Spirit has 
Battle Fury.
Phoenix
* Spiked Carapace reacts on any of the damage over time from Phoenix's abilities and can interrupt Sun Ray and Icarus Dive.
Naga Siren
* 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. And to make things worse, Nyx Asassin is not a common Battle Fury, 
Maelstrom, Mjollnir, 
Gleipnir or 
Radiance wielder to counter this problem.
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.
Naga Siren
* Illusions make it difficult for Necrophos to target his Reaper's Scythe correctly, thus giving illusion heroes like Chaos Knight or Naga Siren an edge against Necrophos.
Naga Siren
* Luna's 
Moon Glaives and 
Lunar Blessing can clear waves of Naga Siren's illusions from Mirror Image.
* Once Naga Siren's illusions are cleared with Aghanim's Shard upgraded Moon Glaives, 
Eclipse can often finish off Naga Siren before she can escape with Song of the Siren.
* A well-timed Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Lucent Ministun talent can be casted at long range and allow Luna to burst down Naga Siren faster and repetively stun Naga Siren, preventing her from escaping with Song of the Siren and 
Town Portal Scroll without getting caught in it's range.
* Luna is a natural Black King Bar wielder unlike Naga Siren who barely goes for it, which allows Luna to freely attack Naga Siren during Song of the Siren and potentially get rid of the most of the damage and crowd-control from Naga Siren.
Additional:
* Luna's Moon Glaives and Lunar Blessing can clear waves of Naga Siren's illusions from Mirror Image.
* Once Naga Siren's illusions are cleared, Eclipse can often finish off Naga Siren before she can escape with Song of the Siren.
* A well-timed Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Lucent Ministun talent can be casted at long range and allow Luna to burst down Naga Siren faster and repetively stun Naga Siren, preventing her from escaping with Song of the Siren and Town Portal Scroll without getting caught in it's range.
* Luna is a natural Black King Bar wielder unlike Naga Siren who barely goes for it, which allows Luna to freely attack Naga Siren during Song of the Siren and potentially get rid of the most of the damage and crowd-control from Naga Siren.
Naga Siren
* 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.
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.
Naga Siren
* Illusion or summon-based heroes can be a problem to Viper due to his lack of AoE damage: Naga Siren, Phantom Lancer, Beastmaster
Additional:
* Naga Siren can easily disjoint, and dispel Corrosive Skin with Mirror Image.
* Since Viper is mostly a single-target hero, he will not have almost any chance against Naga Siren because she is an illusion based hero.
* Viper has no burst damage, so Naga Siren will have plenty of time to use Aghanim's Shard upgraded Song of the Siren heal her allies before Viper can finish them off.
Naga Siren
* Medusa's 
Split Shot and 
Mystic Snake combined with Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's 
Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Additional:
* Medusa's Split Shot and Mystic Snake combined with Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Naga Siren
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: 
Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, 
Slark.
Naga Siren
* Avalanche and Toss combo makes short work of Mirror Image's illusions.
* Tiny's cleave with Tree Grab and area of effect damage with Tree Volley will easily wipe out illusions.
Phoenix
* Heroes that are able to slow Tiny's attack speed, like 
Tusk and 
Phoenix, will greatly limit his Physical damage output.
Naga Siren
* Naga Siren can make landing Chen's combo very hard due to her being an illusion hero thanks to Mirror Image.
* 
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.
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.
Naga Siren
* Unless Lone Druid purchases a Black King Bar for his Spirit Bear, Ensnare will easily kite the Spirit Bear.
* Song of the Siren allows Naga Siren and her team to completely bypass the Spirit Bear and hunt for the Lone 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.
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.
Naga Siren
* Heroes with illusions and summons can be hard for Phantom Assassin to deal with, as she lacks any AoE abilities to deal with them without items: Broodmother, Phantom Lancer, Chaos Knight, Lycan, Naga Siren, 
Shadow Shaman, Visage, Nature's Prophet, Terrorblade, 
Warlock, 
Wraith King.
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).
Naga Siren
* 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.
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.
Naga Siren
* 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.
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
Naga Siren
* 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.
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.
Naga Siren
* 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
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
Naga Siren
* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother
Phoenix
* Heroes with strong area damage to destroy Phantasm illusions: 
Axe, Ember Spirit, 
Legion Commander, Phoenix
Naga Siren
* Naga Siren can very easily dispel the 
Reflection with Mirror Image. And Besides Reflection that can be used to detect real Naga Siren, Terrorblade has no other ways to deal with Naga Siren's illusions. And what's worse is that Naga Siren can much easily detect the real Terrorblade due to 
Conjure Image having illusions having different colors. In addition, Terroblade is not a common Battle Fury nor Mjollnir wielder to counter this problem.
* Aghanim's Scepter upgraded Ensnare will allow Naga Siren to root Terrorblade even ithrough Black King Bar. And with Aghanim's Scepter, Naga Siren can get access to Reel In ability, which can allow her to pull Terrorblade toward herself and her team and away from his illusions, even through Black King Bar.
* Naga Siren can rapidly damage Terrorrblade and weaken Terrorblade's armor with Rip Tide, which combined with Terrorblade's low health and strength gain can almost completely discourage Terrorblade from even being present in teamfights. Rip Tide can also weaken armor of Terrorblade's illusions and damage them.
* Song of the Siren can be used to save an ally whom Terrorblade has used 
Sunder under the condition Naga Siren is quick enough to do it. And since Terrorblade has no "real" burst damage potential outside from Sunder, Naga Siren will usually have plenty of time to save an allied hero on which Sunder was used. Aghanim's Shard upgraded Song of the Siren can also heal her allies around her for it's duration, which allows Naga Siren to nullify effects of Sunder.
* However, Naga Siren's lack of burst damage can make it difficult for her to burst down Terrorblade before he can use Sunder unless Naga Siren has either Black King Bar or 
Linken's Sphere to protect herself against it or if she is played as Nuker.
Additional:
* Naga Siren can very easily dispel the Reflection with Mirror Image. And Besides Reflection that can be used to detect real Naga Siren, Terrorblade has no other ways to deal with Naga Siren's illusions. And what's worse is that Naga Siren can much easily detect the real Terrorblade due to Conjure Image having illusions having different colors. In addition, Terroblade is not a common Battle Fury nor Mjollnir wielder to counter this problem.
* Aghanim's Scepter upgraded Ensnare will allow Naga Siren to root Terrorblade even ithrough Black King Bar. And with Aghanim's Scepter, Naga Siren can get access to Reel In ability, which can allow her to pull Terrorblade toward herself and her team and away from his illusions, even through Black King Bar.
* Naga Siren can rapidly damage Terrorrblade and weaken Terrorblade's armor with Rip Tide, which combined with Terrorblade's low health and strength gain can almost completely discourage Terrorblade from even being present in teamfights. Rip Tide can also weaken armor of Terrorblade's illusions and damage them.
* Song of the Siren can be used to save an ally whom Terrorblade has used Sunder under the condition Naga Siren is quick enough to do it. And since Terrorblade has no "real" burst damage potential outside from Sunder, Naga Siren will usually have plenty of time to save an allied hero on which Sunder was used. Aghanim's Shard upgraded Song of the Siren can also heal her allies around her for it's duration, which allows Naga Siren to nullify effects of Sunder.
* However, Naga Siren's lack of burst damage can make it difficult for her to burst down Terrorblade before he can use Sunder unless Naga Siren has either Black King Bar or Linken's Sphere to protect herself against it or if she is played as Nuker.
Phoenix
* 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.
Additional:
* 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
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Naga Siren
* 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.
* 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
Additional:
* Ensnare disables Templar Assassin's invisibility and Blink Dagger (a core item on Templar Assassin), and her illusions will break 
Refraction easily.
Phoenix
* 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.
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.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Naga Siren
* 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.
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.
Phoenix
* Icarus Dive quickly escapes from Shadow Demon abilities, especially 
Demonic Purge.
* Phoenix AoE abilities remove Shadow Demon's illusions created by 
Disruption.
Naga Siren
* Ensnare with her attacks allows Naga Siren to gank Sniper easily.
* Rip Tide removes Sniper's very little armor.
Naga Siren
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, Chaos Knight, Terrorblade, Naga Siren
Naga Siren
* Song of the Siren lasts long enough to prevent a successful 
Duel (but only if Naga wasn't the target).
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.
Naga Siren
* 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.
Additional:
* Even though Naga Siren relies on direct attacks to deal damage for most of the time, Song of the Siren allows her to easily waste Guardian Angel.
* Ensnare fully works on targets affected with 
Heavenly Grace. 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.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
Naga Siren
* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan.
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.
Naga Siren
* 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 can prevent Teleportation. Aghanim's Scepter upgraded Ensnare can also affect Nature's Prophet even if he is spell immune. And Reel In from Aghanim's Scepter can also be used to separate Nature's Prophet from his treant and bring him close to Naga Siren and her team to burst him down.
* Song of the Siren will stop Nature's Prophet from escaping even if he has hidden inside of Sprout. Aghanim's Shard upgraded Song of the Siren can also heal her allies and save them from Nature's Prophet.
Additional:
* 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.
Naga Siren
* Lycan is a hero focused entirely on single target physical damage and lacks disables or AoE damage. Due to this, he will have difficulties dealing with illusions or Naga Siren's Ensnare.
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.
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
* 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.
Phoenix
* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, 
Pudge, 
Bristleback, 
Mars.
Naga Siren
* 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.
Naga Siren
* 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.
Phoenix
* Heroes who depend on attacks (such as 
Shadow Fiend or 
Drow Ranger) can be nullified by Fire Spirits' attack speed slow.
Phoenix
* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, Pudge, Bristleback, Mars.
Phoenix
* Heroes who depend on attacks (such as Shadow Fiend or Drow Ranger) can be nullified by Fire Spirits' attack speed slow.
Phoenix
* Heroes with high health especially Strength heroes will take more damage on Sun Ray: Axe, Pudge, Bristleback, Mars.
Naga Siren
* 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. Even though Bounty Hunter can use 
Track on her, Mirror Image will dispel the effect. Ensnare also reveals invisible units while they're rooted, putting Bounty Hunter at a disadvantage.
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.
Naga Siren
* 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.
Phoenix
* Heroes with hiding abilities can protect disabled allies: Outworld Destroyer, Shadow Demon, Tusk, Phoenix with Aghanim's Scepter.
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.
Naga Siren
* 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.
Additional:
* 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.
Phoenix
* Phoenix turns night to day, overriding Dark Ascension during Supernova.
Naga Siren
* Illusion heroes, such as Naga Siren, Phantom Lancer, Chaos Knight, Terrorblade will become strong against Tinker in the late game. 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.
Naga Siren
* 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.
Naga Siren
* Heroes with summons and illusions such as Broodmother and Naga Siren, are ill-suited for Wraith King to fight, as he has no source of waveclear.
Naga Siren
* Heroes with long cast animations can be continuously interrupted by Battery Assault: 
Centaur Warrunner, Jakiro, Leshrac, Naga Siren, Underlord.
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
* 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.
Naga Siren
* Because of his massive AoE damage, Sand King is very effective against illusion heroes: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren.
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.
Phoenix
* Heroes that deal damage over time will also fail to bring down Abaddon and his allies, such as Huskar, 
Venomancer, or Phoenix.
Naga Siren
* 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.
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.
Naga Siren
* 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.
Naga Siren
* Heroes who are illusion based, or even heroes who frequently build Manta Style can be cleared quickly by Pangolier's high damage, or lose their damage ouput because of Lucky Shot: Chaos Knight, Naga Siren
Naga Siren
* 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
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.
Naga Siren
* 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.
Naga Siren
* Axe will destroy her illusions by proccing 
Counter Helix more often due to him being hit by more attacks.
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.
Naga Siren
* Dazzle can instantly destroy all of Naga Siren's illusions from Mirror Image with Aghanim's Shard upgraded 
Poison Touch used on her or any of her illusions.
Naga Siren
* 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.
Naga Siren
* Mirror Image's illusions increase Echo Slam's damage.
Additional:
* Earthshaker's strong AoE abilities can clear Naga Siren's illusions, or at least make it easier to distinguish the real one by the damage they take.
* 
Echo Slam deals more damage against more enemies, which can be devestating against Naga Siren and her illusions.
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.
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.
Naga Siren
* Heroes with illusions: Chaos Knight, Naga Siren, Phantom Lancer, Terrorblade
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
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
* Phoenix's limit AoE, damage-over-time abilities give Io plenty of time to save allies with Relocate.
Naga Siren
* 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.
Additional:
* 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.
* 
Spirits'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.
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
Naga Siren
* 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.
Phoenix
* 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.
Additional:
* 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.
Naga Siren
* 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.
Additional:
* 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.
Naga Siren
*
Mortimer Kisses can make quick work of Naga Siren's illusions. 
Scatterblast and 
Firesnap Cookie's AoE damage are also decent ways to deal with Naga's illusions.
*
Phoenix
*
Lil' Shredder will make quick work of 
Supernova. 
Mortimer Kisses can easily hit a Phoenix using 
Sun Ray.
*