* 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.

* Laguna Blade can kill Dazzle quickly before he casts Shallow Grave.

* Being a hero with low health and abysmal mobility, Lina can nuke her down easily.
* Since Crystal Maiden's Freezing Field is a channeled ability, Lina can use her Light Strike Array to cancel it 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.
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.

* 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.

* Heroes with summons can find their summons eliminated easily by Lina, like Broodmother, Nature's Prophet, and Chen.

Additional:
* Lina can easily prevent Nature's Prophet Teleportation escape attempts with Light Strike Array.
* Lina's Dragon Slave and Light Strike Array can kill Nature's Prophet's treants and grant her lot of farm.
* Nature's Prophet doesn't like buying Black King Bar, which is only item that can help him against Lina.

* 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.

* Heavy nukers will do well against Cold Embrace (Lina, Zeus etc).

* Laguna Blade deals amplified magical damage (pure from Aghanim's Scepter) to Necrophos when he is under the effects of Ghost Shroud.
Additional:
* Laguna Blade's damage will be greatly amplified during Ghost Shroud.

* 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.

* Lina has very high magic burst damage to use against the low-health-pool Luna. Laguna Blade can also be upgraded with Aghanim's Scepter to bypass Luna's Black King Bar, making Lina even more of a threat.

* Heroes that create illusions (such as 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 and the aforementioned 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).

* Heroes with high magical burst can easily kill Huskar when he is at low health: Lion, Lina, Skywrath Mage

* 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.

* Lina is a common Eul's Scepter of Divinity carrier which can waste some duration of Borrowed Time and following up with Laguna Blade if timed correctly.

* 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.

* 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.

* Heroes with summons can find their summons eliminated easily by Lina, like Broodmother, Nature's Prophet, and Chen.

Additional:
* Lina's high damage burst from Dragon Slave, Light Strike Array and Laguna Blade can easily kill Chen's allies or Chen himself before he can use Hand of God.

* Lina can burst Vengeful Spirit down, provided she can land Light Strike Array before Vengeful Spirit lands her Magic Missile.
* Laguna Blade deals massive damage, often being enough to kill a squishy Vengeful Spirit.

* Enchantress has pitiful health, and cannot tank Lina's heavy magic damage.
* Untouchable is decently countered by Fiery Soul, exposing Enchantress' weakness to physical damage due to her low armor.
* Lina is decent at clearing creeps and can kill Enchantress' creeps quickly.
Additional:
* Enchantress has a very small health pool and cannot tank Lina's heavy magic burst.
* Untouchable is decently countered by Fiery Soul, exposing Enchantress' weakness to physical damage due to her low armor.
* Lina is decent at clearing creeps and can kill Enchantress' creeps quickly.

* 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 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 Siren is one of the most natural Diffusal Blade carriers, the bane of every hero with a small mana pool.

* Dragon Slave will make quick work of the spawned illusions from Disruption.
* An attempt to save an ally using Disruption can easily become a perfect setup for a Light Strike Array for the enemy.
* Lina usually builds Eul's Scepter of Divinity to dispel Shadow Poison and Soul Catcher and Linken's Sphere to block Disruption and Demonic Purge.
* Shadow Demon doesn't have the burst damage to take Lina out of the fight quickly, although Demonic Purge can help his allies kill a squishy Lina.

* Dragon Slave deals reliable magic damage during the laning phase against Mars.
* Lina's Eul's Scepter of Divinity and Light Strike Array combo can interrupt Mars from being disruptive for a decent amount of time and leave him vulnerable for follow up stuns.
* Laguna Blade deals massive magical damage, and pure damage with Aghanim's Scepter.

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

* Light Strike Array and Dragon Slave allows Lina to destroy trees, countering Nature's Guise and Eyes in the Forest.
* Lina has many tools to remove Living Armor's protection.

* Venomancer has low health, which makes him vulnerable to Lina's heavy magic damage.
* Fiery Soul attack speed bonus removes Plague Wards easily in all stages of the game.

* Light Strike Array destroys the tree Monkey King is standing on.
* Lina's Laguna Blade high damage burst can kill Monkey King before he has Jingu Mastery bonuses.

* Eul's Scepter of Divinity and Light Strike Array combo will disable Mirana if she tries to Leap away.
* Laguna Blade's magical (pure with Aghanim's Scepter) burst damage takes advantage of Mirana's below average health.
Additional:
* Moonlight Shadow does little good against Dragon Slave and Light Strike Array.
* Lina's damage burst can quickly kill Mirana's teammates before she saves them with Moonlight Shadow.

* Lina builds Shadow Blade (and upgrades it into a Silver Edge), which makes it hard for Ancient Apparition to land his abilities.
* Laguna Blade can kill Ancient Apparition easily due to his low health pool and lack of mobility.

* Lina's damage burst can quickly kill Clinkz before he saves them with Skeleton Walk.
* Fiery Soul attack speed bonus removes Burning Army easily in all stages of the game.

* 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:
* 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.

* 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.

* 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.

* 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.

* Heroes who deal single instance burst damage will only proc Bristleback once: Lina, Lion.

* Heroes with high damage output who can burst down Morphling before he has time to use Attribute Shift (Strength Gain), like Lina and Lion.

Additional:
* Light Strike Array catches Morphling while he jumps in from Waveform and also prevents Morphling from using his abilities.
* Laguna Blade can kill Morphling quickly before he shifts into Attribute Shift (Strength Gain).

* Heroes with high burst damage: Lina, Lion, Luna, Nyx Assassin, Queen of Pain.

* Heroes with low health or rely on evasion can easily be bursted down, like Phantom Assassin or Terrorblade.

Additional:
* Laguna Blade is one of the best tools to kill Terrorblade before he can use Sunder due to its high magical (pure with Aghanim's Scepter) burst damage.
* Dragon Slave allows Lina to clear Terrorblade's illusions from Conjure Image and Manta Style.

* Heroes who have channeled abilities can be stunned by Light Strike Array, like Witch Doctor with Death Ward and Bane's Fiend's Grip.

Additional:
* Light Strike Array cancels out Death Ward from a long distance.

* 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.

* Any hero reliant of mobility, like Storm Spirit.

* 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

* 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.

* 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 can kill Death Prophet with nukes can prevent her from using Exorcism to its full duration or using it at all: Lina, Lion, Puck, Morphling.

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

* Heroes with summons can find their summons eliminated easily by Lina, like Broodmother, Nature's Prophet, and Chen.

Additional:
* Light Strike Array in combination with Dragon Slave can easily clear Broodmother's spiders.
* Laguna Blade offers extensive damage that can kill Broodmother early on or before she is able to use Insatiable Hunger in attempts to salvage a fight.

* 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.

* Heroes who have channeled abilities can be stunned by Light Strike Array, like Witch Doctor with Death Ward and Bane's Fiend's Grip.

* 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.

* Lycan is a hero focused entirely on single target physical damage and lacks disables or AoE damage. Due to this, he can't deal with illusions or Naga Siren's Ensnare.

* Light Strike Array catches Meepo and his clones if he tried to gank Lina with Earthbind & Poof.
* Laguna Blade can quickly kill Meepo and his clones before they escape with Poof.

* Pudge has low armor and mobility, making him suspectible to her physical attacks (if Lina is the carry).
* Because Dismember is a channeled ability, it can be canceled through Light Strike Array within a distance.

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

* 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.

* Song of the Siren is very difficult for Rubick to Spell Steal when he is affected by sleep. However, if Rubick does successfully steal it, the Song will allow his team to initiate from unexpected angles.
* 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.

* Heroes with powerful spammable abilities will prove problematic for Grimstroke as Ink Swell does not protect him from them: Zeus, Skywrath Mage, Tinker, Lina

* 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.
* However, Nethertoxin can clear her illusions quickly if Naga Siren does not micromanage them well.

* 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

* 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.

* Laguna Blade ends Gyrocopter very quickly in the early to mid game.

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

* Since Windranger is bad against magical damage, heroes with continuous magical damage or magical nukes can blast her: Zeus, Tinker, Leshrac, Viper, Skywrath Mage, Lion, Lina, Venomancer.

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