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

* Lifestealer can close the distance to Sniper by using Infest on a fast or durable creep to tank Sniper's damage.
* Open Wounds will reduce Sniper's mobility heavily, and Rage's attack speed bonus helps in taking down Sniper.

* 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.

* Rage ignores all of Viper's magical damage.
* Feast and Open Wounds combine to heal through Viper's physical damage.

* 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.

* Rage renders Lifestealer immune to the damage from Burning Spears and Life Break.
* Feast and Open Wounds makes Lifestealer one of few heroes that can outlast Huskar in a one-on-one fight.

* Rage will dispel Laser's blind and turns him spell immune for the duration so Tinker cannot damage him.
* Feast will quickly bring down Tinker due to being so fragile.
Additional:
* Lifestealer's Rage makes him immune to all of Tinker's damage and debuffs.
* Lifestealer can infest any mobile hero (teams usually pick one against Tinker), which ensures that Tinker will die if he is caught.

* 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.

* Lifestealer's Rage lets him clear Remote Mines and Proximity Mines with proper vision.
Additional:
* Rage protects Lifestealer from all of Techies' magic damage and disables and dispels Stasis Trap's debuff .
* Usually teams will have a hard time pushing high-ground against Techies, but Lifestealer can just pop Rage and walk uphill without fear of Techies.

* Heroes with summons like Broodmother,Enigma, Invoker, Nature's Prophet, Lycan, Visage;or illusions, like Naga Siren, Phantom Lancer, Terrorblade are effective at keeping the choke points and rune spawns safe from Proximity mines in the early game.

* Rage can be used to escape from a Glimpse and to move out of Kinetic Field.
* Infest allows Lifestealer to dodge Glimpse.

* 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

* 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.
Additional:
* Mirror Image can dispel Frostbite.
* Ensnare and Song of the Siren can stop Freezing Field.
* Song of the Siren can allow her team to quickly close the gap on Crystal Maiden.

* Juggernaut and Lifestealer have abilities (Blade Fury and Rage respectively) that prevent Crystal Maiden from using her spells on them in the early game, before Black King Bar and other magical reduction is even an issue.

* Slark, Lifestealer, Morphling and such with a good escape mechanism are a nuisance to deal with in the early-game.

* Song of the Siren stops him from acting and her illusions can push better than him because Mirror Image has a longer duration.
* Arc Warden does not often build Radiance, which is useful for illusions and countering illusion pushes.
* Mirror Image dispels Flux or prevents Flux's slow.
Additional:
* Her illusions can push better than Arc Warden's Tempest Double because Mirror Image has a longer duration.
* Mirror Image dispels Flux, and the illusions stop Flux from working.

* Heroes that can instantly kill creeps greatly reduce the effectiveness of Chen's converted army: Lifestealer, Doom, Mirana, Clinkz.

* Illusion and heroes with summons are difficult to kill with Chen's single-target offensive spells: Terrorblade, Phantom Lancer, Chaos Knight, Broodmother, Naga Siren, Lycan, Visage. However, Chen can convert enemy summons with Holy Persuasion, as long as they don't bunch up.

Additional:
* Naga Siren can make landing Chen's combo very hard due to her being an illusion hero.
* Ensnare will prevent Chen from activating Hand of God.

* 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 dealer, so he will not fare well against Naga Siren. He might as well try to Track her, but her Mirror Image will dispel the effect. Also, Ensnare reveals invisible units while they're rooted, putting Bounty Hunter in a tricky situation.

* Lifestealer with Rage and Infest
* 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.

* Rage allows him to dispel Blinding Light from himself.
* Open Wounds allows him to slow and kill Keeper of the Light.

* Rage negates Kunkka's X Marks the Spot.
* As a strength hero with high strength gain and very little armor, as well as low agility gain, Kunkka is vulnerable to Lifestealer's Feast and Open Wounds.

* The lifesteal of Feast scales accordingly to the health of its target, which is effective against Pudge due to his high health and further health granted by stacks of Flesh Heap.
* Lifestealer can activate Rage to completely negate magic damage, therefore rendering the damage of Rot and Dismember null.
* Pudge's plentiful health makes him an ideal target for Open Wounds.

* 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 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.

* 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 will prevent Rubick from spamming his abilities from Spell Steal.
* Mirror Image allows to dodge the incoming stun from Telekinesis (when she is not a target) and it can also to dodge and dispel Fade Bolt's damage reduction debuff.

* Rage protects Lifestealer from all of Lina's abilities (except an upgraded Laguna Blade).
* Open Wounds is great to keep Lina in place because she has no abilities to help her escape.

* Feast deals damage and heals Lifestealer based on the target's maximum HP, which is greatly effective against naturally high HP heroes such as Doom.
* Rage allows Lifestealer to become spell immune to negate the magical damage of Infernal Blade and Scorched Earth.
* Doom has no effective means of escape from Open Wounds. This is particularly devastating in lane, where Doom may have to play a much more passive, conservative play style as a result.

* 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 tankiness. Plus, the said item makes Naga Siren harder to be distinguished from her illusions.

* Rage completely negates all of Nyx Assassin's abilities except Vendetta, while Open Wounds allow him to quickly close the gap.
* Infest combined with an ancient creep makes Nyx Assassin an easy target with Dust of Appearance or a Gem of True Sight.

* Rage protects Lifestealer nearly from all of Invoker's spells.
Additional:
* Rage grants immunity from Invoker's spells and can dispel most of the disables such as the armor loss from Forge Spirit and the constant stuns of Cold Snap.

* Song of the Siren can be used to time out Guardian Angel, giving Naga Siren's team an easy opportunity to counter-initiate.
Additional:
* 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 is one of the most natural Diffusal Blade carriers, the bane of every hero with a small mana pool.

* Ensnare is good vs bear.
* In teamfights, song of the siren may be used to properly set up and coordinate an attack on Lone Druid in the backline, bursting him down, allowing to completely ignore the bear.
* Druid lack innate AoE capabilities giving him no good way of dealing with illusions.

* Feast is good against high health strength heroes such as Alchemist.
* Rage allows Lifestealer to not be targetable by Unstable Concoction, possibly making Alchemist stun himself.

* Ogre Magi has nothing against Rage and his high health pool amplifies Feast.
Additional:
* Lifestealer's Rage makes him immune to all of Ogre's magical debuffs and also dispels them.
* Ogre's as hero with great durability and high health is great target for Lifestealer in any stage of the game, thanks to Feast.

* Rage protects and dispels all of Dark Willow's abilities.
Additional:
* Rage protects Lifestealer from all of Dark Willow's abilities.

* 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 and Crippling Fear.
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 with burst damage of their own won't be afraid to go toe to toe with Void Spirit, like Ursa, Lifestealer, or Axe.

* Any hero reliant of mobility, like Storm Spirit.

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

* 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.

* 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.

* In general, heroes with spell immunity abilities won't be caught inside by Pit of Malice: Juggernaut, Lifestealer.

* Naga Siren is a natural split-pusher. With a Radiance equipped, she will easily out-push Nature's Prophet, farming his treants in the process.
* Ensnare prevents Teleportation. Even if he hid inside Sprout, Song of the Siren lasts long enough to prevent him from escaping.
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.

* Feast is an effective tool against Centaur Warrunner, who generally has high health and low armor, and compensates the reflected damage of Retaliate.
* If activated, Rage protects Lifestealer from Hoof Stomp, Double Edge, and Stampede.

* Song of the Siren can be used to nullify the effects of Winter's Curse, and when upgraded with Aghanim's Scepter it also outmatches the heal of Cold Embrace.
* If Winter Wyvern is reckless enough to put an ally in Cold Embrace, Naga Siren will be able to use her Ensnare to extend the disable on the hero affected by Cold Embrace.

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

* Rage grants Lifestealer immunity to all of Jakiro's spells. Note: magic resistance will not dispel the attack speed slow effects from Dual Breath and Liquid Fire.

* Lifestealer excels at killing high health heroes with Feast, and Sven is no exception.
* Rage stops Storm Hammer from hitting Lifestealer.
* Rage and Open Wounds helps Lifestealer survive against Sven's high physical damage.

* With Feast and Rage, Lifestealer is nearly impossible for Clockwerk to bring down, and is the last hero Clockwerk wants to be trapped with in Power Cogs.

* Rage ignores all of Gyrocopter's magical attacks.
* Open Wounds makes it hard for Gyrocopter to get away.
* Feast helps Lifestealer out-damage Gyrocopter at close range.

* Heroes with spell immunity or pseudo-blinks which provide invulnerability: Lifestealer, Juggernaut, Omniknight, Huskar , and Tusk have spells which allow them to easily escape Dream Coil.

* Feast will deal a large amount of damage to Tiny's large health pool.
* Rage protects Lifestealer from Tiny's magical burst damage.

* Rage provides spell immunity to Lifestealer and thus nullifies all of Lion's abilities.
* Open Wounds allows Lifestealer to easily catch Lion out and prevent him from escaping.

* Heroes with powerful rooting abilities will disable most of Pangolier's skill, a bonus point if it pierce 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

* Leshrac's high magic damage is ignored by Rage.
* Lifestealer can get in Leshrac's face with Rage and mitigate any other damage taken by Leshrac with Open Wounds.

* 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), Pugna

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

* Feast's lifesteal makes it nearly impossible for Axe to initiate and bring Lifestealer's health low enough for Culling Blade, even with many procs of Counter Helix.
* Feast's damage is calculated as a percentage of health, turning Axe's high health against him. This allow Lifestealer to hit Axe much harder than most other heroes.
Additional:
* Feast makes it impossible to put Lifestealer's health for a Culling Blade and also deals high damage to Axe due to his naturally high health.
* However, Lifestealer's Rage can be pierced by Berserker's Call.

* Rage prevents Earthshaker from damaging and stunning Lifestealer.
* Feast is very effective against Earthshaker, because of him being a strength hero, allowing Lifestealer to heavily harass and kill him.
* Open Wounds prevents Earthshaker from escaping after he initiated.
* Infest gives Lifestealer an easy way to escape should he get caught out by Earthshaker.

* 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.

* Lycan is a carrier built entirely with physical attacks, having 0 AoE presence and no spell power. Due to this, he can't deal with illusions or Naga Siren's Ensnare.

* Heroes with magic immune abilities can negate most of Visage's attacks like Pangolier and Lifestealer.

* 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.

* Rage is very useful against Zeus, as it negates magic damage and provides spell immunity. In addition, the increased attack speed can tear Zeus apart in combination with Open Wounds.
* Lifestealer can avoid Thundergod's Wrath with Infest.