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

* Even if he can slow Mars down with Shrapnel and Headshot, Mars can tank Sniper's physical damage simply by facing him with Bulwark, allowing him to endure his auto-attacks into the late-game. Should Sniper choose to attack someone else, Mars can redirect his projectiles with Bulwark's active ability.
* Sniper's poor mobility makes him very vulnerable to Arena of Blood, especially in the early game. Mars can also take advantage of this by pushing him closer to the front line with Spear of Mars.

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

* Bulwark negates most of the physical damage from Terrorblade and his illusions.
* God's Rebuke and Spear of Mars can decimate Terrorblade's illusions quickly.

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

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

* 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.

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

* 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.

* 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 and Depth Shroud.
* Should Pounce be on cooldown, Slark is very vulnerable inside Arena of Blood.

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

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

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

* Heroes with forced movement abilities or non-interrupting forced movement, such as Lion, Drow Ranger, Magnus, Mars, as they can cancel blast-off mid air, removing his ability to initiate or escape.

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

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

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

* 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.

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

* 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.

* If visible, Mars can knock Monkey King off his Tree Dance with God's Rebuke, as well as Spear of Mars. Arena of Blood also destroys a large swath of trees, which can disrupt Monkey King's positioning and turn him vulnerable should he choose to hide in trees.
* Mars can endure Jingu Mastery attacks simply by facing him with Bulwark.
* Mars can end Wukong's Command early by displacing Monkey King with a well-thrown Spear of Mars. Mars can also endure most of his clones with Bulwark.
Additional:
* 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.

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

* 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.

* Shukuchi cannot help Weaver escape from Arena of Blood, and can most likely die if detected through invisibility.
* If pinned to the arena's walls, Time Lapse tends to not be enough to save Weaver, as God's Rebuke can keep him burst down thanks to its damage scaling.
* The Swarm and Geminate Attack are not enough to pierce through Bulwark.

* As long as Mars is facing her with Bulwark, even if pushed away with Gust, Drow Ranger will do no effectual damage against him. Mars' ability to endure her onslaught usually gives him enough time to cast Arena of Blood, of which she has a very slim chance surviving without Gust.
* With Bulwark's active ability, Mars can protect allies pursued by Drow Ranger by redirecting her projectiles to his shield instead.

* 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.

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

* Spectre cannot have a good game if she is pressured heavily in lane, which is something Mars can do. He may even force her to cast Haunt as an escape, putting it on a long cooldown.
* Should Spectre get to the late game, Mars can block a large amount of her damage with Bulwark and can mitigate some of the chaos caused by her Haunt illusions with God's Rebuke.

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

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

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

* Because Duel requires both combatants to face each other, Bulwark's effectiveness will be increased by a huge margin, which makes it much more difficult for Legion Commander to win any duels against him.
* Spear of Mars and God's Rebuke pushes Legion Commander away during Duels against allies.
Additional:
* Bulwark immensely mitigates Duel, even with bonus physical damage, as Bulwark scales by percentage. Mars can also buy time for a dueled ally by pushing Legion Commander away with Spear of Mars.

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

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

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

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

* Heroes with summons and illusions such as Broodmother and Naga Siren, are ill-suited for Wraith King to fight, as he has no source of waveclear.

* 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.

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

* Illusion-based heroes are effective against Omnislash and Juggernaut's single-targeted damage: Naga Siren, Chaos Knight, Terrorblade,Phantom Lancer.

* Bulwark mitigates Omnislash which deals physical damage, severely reducing its damage.
* Omnislash switch to opposite direction with each slash, so Mars can easily reduce most of its damage.
* However because {Ability ID:Blade Fury|Juggernaut} gives spell immunity Juggernaut can easily escape from {Ability ID:Arena Of Blood|Mars}.
Additional:
* 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.

* 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.

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

* 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.

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

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

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

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

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

* 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.

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

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

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

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

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

* 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,Drow Ranger.

* Bulwark can make each of Medusa's attacks target him instead, reducing Medusa's contribution on team fights.
* Spear of Mars stuns Medusa and also pushes her away from teamfights, taking advantage of Medusa's low mobility.
* Arena Of Blood blocks Medusa's attacks from outside the arena.

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

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

* 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.

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