* Medusa is a fairly immobile hero that deals damage around her with Split Shot. Sniper should outrange her and should stay out of harm's way from Split Shot.
* More importantly, Sniper should have enough attack range to fire at Medusa during her Stone Gaze without turning to stone, so the ultimate is mostly wasted against him.
Additional:
* Sniper can outrange both Medusa's arrows and Stone Gaze, allowing him to focus her down during a teamfight.

* 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 with channeled abilities which Assassinate may cancel at long range: Witch Doctor, Crystal Maiden, Shadow Shaman, Pugna

* 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.

* Sniper usually sits at the back and it's hard for Luna to get close to him to attack.
* Due to Sniper's Shrapnel and his long range, Luna has a hard time taking high ground despite her Moon Glaives being fantastic for taking Barracks and buildings.

* 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 who Sniper can kite: Sven, Wraith King, Kunkka, Doom, Tidehunter, Underlord, Troll Warlord, and etc.

* 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.

* With his Take Aim, Sniper can simply sit out of your ability range and deal massive damage if not killed first.
* Assassinate can target allies who are still alive with low health because of Ghostship's buff.
* Headshot makes it harder for Kunkka to position/escape and makes it hard for Kunkka to hit with Tidebringer.

* 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 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.

* Shrapnel can be used to cancel Shadow Fiend's Blink Dagger from a huge range.
* Take Aim and Headshot allow Sniper to harass Shadow Fiend in lane without getting into the range of his Shadowraze.
* Assassinate can be used to cancel Shadow Fiend's Requiem of Souls if he is not a target.
Additional:
* Shrapnel can be used to cancel Shadow Fiend's Blink Dagger from a huge range.
* Take Aim and Headshot allow Sniper to harass Shadow Fiend in lane without getting into the range of his Shadowrazes.

* Take Aim allows Sniper to outrange Drow Ranger and deal damage at her without much fear of retaliation
* Sniper can slow down Drow Ranger with Shrapnel, and both Shrapnel and Assassinate makes it easier for Sniper's team to track and take her down
Additional:
* Somewhat like Medusa, Drow Ranger is a fairly immobile hero that hopes to be able to attack without dying. Sniper should outrange her.
* Shrapnel and Assassinate provides vision over her, and slows her down, making it easier for you team to focus on taking her down
* Be careful however that if she starts attacking you, she packs a bigger punch than you thanks to Marksmanship.

* 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.

* Sniper is a pure right click carry with a very long range, making it hard for Silencer to cast any of his skills on him in lane. During team-fights, Global Silence has little impact on Sniper.
Additional:
* Due to Sniper having a such a long range, he will rarely get hit by any of Silencer's spells.
* Global Silence will not hinder Sniper much as other heroes since most of his damage output comes from his attacks.

* 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.

* Sniper can kill Disruptor while he is trapped by Kinetic Field from a long range.
* Sniper generally stays in the back, making it hard for Disruptor to cast any of his skills on him in lane.

* 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

* Sniper can easily destroy Tombstone from long range.

* 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.

* 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.

* 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.

* His increased attack range makes it very hard to get close enough for Static Link, Eye of the Storm and Razor's own attacks.
* Headshot procs will slow Razor heavily regardless of Storm Surge, as it will knock him back for a brief duration.

* Heroes who Sniper can kite: Sven, Wraith King, Kunkka, Doom, Tidehunter, Underlord, Troll Warlord, and etc.

Additional:
* Due to the nature of the hero, Sniper is typically situated in the back of the fight, potentially making him a difficult target to initiate on and fight.
* Sniper is largely a right-click hero, and as such isn't as an effective of a Doom target as other heroes.
* Thanks to Shrapnel and Headshot, Sniper is able to effectively 'kite' Doom, preventing him from closing the distance between the two.

* Heroes with channeled abilities which Assassinate may cancel at long range: Witch Doctor, Crystal Maiden, Shadow Shaman, Pugna

* 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 that can outrange Plague Ward can neutralize them without putting themselves at risk of receiving Poison Sting: Arc Warden, Chen, Clinkz, Drow Ranger, Lina, Mirana, Nature's Prophet, Pugna and Sniper.
* Special mention to heroes has attack range talent can also outrange Plague Ward.

* 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.

* Heroes who Sniper can kite: Sven, Wraith King, Kunkka, Doom, Tidehunter, Underlord, Troll Warlord, and etc.

* Heroes that can maintain vision on Monkey King can see when he uses Tree Dance: Bloodseeker, Treant Protector with Eyes In The Forest, Sniper, Weaver

* Heroes who Sniper can kite: Sven, Wraith King, Kunkka, Doom, Tidehunter, Underlord, Troll Warlord, and etc.

Additional:
* Sniper's very long range allows him to stay out of Firestorm and Pit of Malice as well as Atrophy Aura range.

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

* Heroes with channeled abilities which Assassinate may cancel at long range: Witch Doctor, Crystal Maiden, Shadow Shaman, Pugna

* Heroes who Sniper can kite: Sven, Wraith King, Kunkka, Doom, Tidehunter, Underlord, Troll Warlord, and etc.

Additional:
* Shrapnel and Headshot allows Sniper to kite Troll Warlord effectively.
* Take Aim together with certain items such as Hurricane Pike allow Sniper to sit and fire at Troll Warlord from a safe distance.

* 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.

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

* 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 with long ranged attacks or abilities can harass Visage from afar like Phoenix and Sniper.

* 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.

* 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.

* Shrapnel can sometimes scout out Magnus and also place his Blink Dagger on cooldown. Aside from that, Sniper likes to stay far back behind enemy lines, so it's difficult to catch him with Reverse Polarity unless you already have vision on him and can Skewer him to the rest of his team.

* Sniper's position in the far back line makes him unlikely to be hit by any of Grimstroke's abilities during teamfights.
* Sniper is relatively unaffected by the silence from Phantom's Embrace.
* Sniper's long range and fast projectile speed allows him quickly to destroy any Phantoms attacking his allies.

* Take Aim and Assassinate allow Sniper to reach Io even if it stays in the backline.

* A Sniper who is somewhat competent at positioning is hardly going to be affected by any of Dark Seer's spells thanks to Take Aim.
* However, an illusion of Sniper made with Wall of Replica is extremely powerful, and hard to deal with.

* Heroes who Sniper can kite: Sven, Wraith King, Kunkka, Doom, Tidehunter, Underlord, Troll Warlord, and etc.

* 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.

* 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.

* Shrapnel can be used to disable Earthshaker's Blink Dagger from long range.
* Take Aim allows Sniper to harass Earthshaker in lane, and stay out of Echo Slam initiation radius.
Additional:
* Sniper is able to kite Earthshaker with his very long range.
* Sniper can dodge Earthshaker's stuns like Fissure and Enchant Totem with mobility items such as Blink Dagger and Shadow Blade/Silver Edge.
* Sharpnel can be used to cancel Earthshaker's Blink Dagger and preventing effective use of his Echo Slam in a majority of situations.

* Powerful physical hitters that can destroy Pangolier during his rolling from afar: Drow Ranger, Sniper, Templar Assassin, Arc Warden

* 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

* Heroes with good counter-push abilities to clear creep waves can hinder Jakiro's early pushing ability: Death Prophet, Sniper, Tinker, Windranger.

* 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.

* As Outworld Devourer has short cast ranges, a short attack range, and no gap-closing abilities, Sniper can kite and harass Outworld Devourer in lane with his long range and zone him out in fights. The continuous area damage from Shrapnel also prevents Astral-Blink escapes.

* Heroes with channeled abilities which Assassinate may cancel at long range: Witch Doctor, Crystal Maiden, Shadow Shaman, Pugna

Additional:
* Sniper's huge range makes him an unviable target to use Life Drain on, forcing Pugna to risk playing out of position to use it on Sniper.
* Sniper's Shrapnel can be used to provide vision on Nether Ward, and his range allows him to easily take it out.
* A clumsy Pugna may accidentally boost Sniper's Shrapnel and Assassinate damages if he recklessly uses Decrepify on himself or his allies.

* 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.

* 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.

* Sniper has a very long range, so it is rare that Enigma can catch him in a Black Hole.
* Assassinate can easily cancel Black Hole if he is not caught, especially with the level 20 talent.
* Enigma's Eidolons from Demonic Conversion are useless to push against a Sniper as he will easily kill them, especially with Maelstrom/Mjollnir.
Additional:
* Take Aim extends Sniper's attack range, allowing him to position himself safely behind his team, making it difficult to catch him in Enigma's relatively small Black Hole AoE. When left unattended, he can quickly kill a channeling Enigma (often from the high ground) to rout an otherwise strong initiation, assuming Enigma does not have Aeon Disk.