Riki
* Axe can disable 
Cloak and Dagger's invisibility with 
Berserker's Call, which forces Riki to attack him at a very bad angle.
* Axe has a very high HP pool, making it hard for you to kill him before you get big items - that is if you survive engaging him. 
Counter Helix ignores Riki's armor and goes straight for his tiny HP pool, totally ignoring 
Smoke Screen.
* Axe is a natural buyer of Blade Mail and Riki generally does not buy lifesteal items, causing Riki to kill himself when attacking due to your tiny HP pool.
Naga Siren
* Axe will destroy her illusions by proccing Counter Helix more often due to him being hit by more attacks.
Riki
* Root is a deadly threat to Riki, disabling both 
Blink Strike and 
Tricks of the Trade while making him fully revealed, making 
Earthbind a good ability against him.
* Smoke Screen may not be able to silence all the Meepo clones.
* Riki has no true area damage, as Tricks of the Trade's damage is distributed between all Meepo clones, so he cannot effectively fight Meepo or deal with his strong ability to push unless Riki has 
Battle Fury.
Naga Siren
* 
Naga Siren's Song of the Siren may be useful but Poof will destroy all of her illusions.
Riki
* Heroes that avoid damage by coming in and out of invisibility in teamfights such as 
Weaver, 
Templar Assassin, and 
Riki will be easy for Zeus to reveal with Lightning Bolt and Thundergod's Wrath, but these heroes usually have other ways to avoid his damage or kill him, so he is not a perfect counter alone.
Additional:
* Zeus's 
Lightning Bolt and 
Thundergod's Wrath provides a short duration of True Sight, revealing Riki while possibly dealing a heavy amount of damage.
* Zeus's 
Nimbus can be placed directly on top of Tricks of the Trade, potentially causing him to be damaged, stunned, and revealed the instant he becomes targetable again.
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.
Riki
* Thirst detects Riki whenever his health is low.
* Rupture does large damage when Riki uses Blink Strike.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: 
Spirit Breaker, 
Bloodseeker, 
Witch Doctor.
Riki
* 
Pit of Malice prevents Riki from casting Blink Strike. or Tricks of the Trade.
* 
Atrophy Aura reduces Riki's damage.
* 
Firestorm can be used to harrass Riki in lane.
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.
Riki
* Riki does little damage to Dragon Knight, as he relies only on physical damage with modest attack speed and lack of burst.
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
* 
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.
Riki
* The bonus Backstab damage from Cloak and Dagger is rendered irrelevant with 
Bristleback and hurts Riki more than him because of the passive Quill Spray.
* Riki can still get damaged by Bristleback's 
Quill Spray while invisible, and it can be hard to deal with in lane.
* Bristleback is not too bothered by Smoke Screen. Though he cannot use Quill Spray manually inside it, it still procs passively when he takes damage from the back. The movement speed from 
Warpath allows him to get out of the area easily.
* Due to Bristleback's natural tankiness, he is an ideal 
Gem of True Sight carrier.
* Riki rarely buys 
Silver Edge to break Bristleback's passive because the invisibility aspect of it is redundant.
Additional:
* Quill Spray will hit Riki even when he is invisible.
* Cloak and Dagger's bonus backstab damage is rendered irrelevant against Bristleback.
* Smoke Screen does not stop Bristleback's passive from activating.
* Due to Bristleback's natural tankiness, he is an ideal Gem of True Sight carrier, directly countering Riki's invisibility.
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.
Naga Siren
* 
Flak Cannon and 
Call Down can easily clear Naga Siren's illusions.
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.
Riki
* 
Static Link drains away Riki's damage while keeping his location revealed for its duration, allowing his team to accurately land detection or area-of-effect skills.
* 
Storm Surge procs on invisible heroes, making him aware of Riki's presence near him.
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.
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.
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.
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.
Riki
* Luna can push very fast with Moon Glaives, which is something Riki cannot deal with well.
* Luna is naturally very fast, making it hard for Riki to trap her in Smoke Cloud.
* Even though Riki can evade 
Eclipse with his invisibility, smart Luna will always buy 
Dust of Appearance, providing vision on Riki to her allies and herself.
Additional:
* Luna can push very fast with Moon Glaives, which is something Riki cannot deal with well.
* Luna is naturally very fast, making it hard for Riki to trap her in Smoke Cloud.
* Even though Riki can evade Eclipse with his invisibility, smart Luna will always buy Dust of Appearance, providing vision on Riki to her allies and herself.
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.
Riki
* All assassin-type carries in a one against one situation: 
Meepo, 
Phantom Assassin, Riki, 
Ursa. Luna's only chances are that she buys 
Ethereal Blade or Black King Bar to gain a slight edge against them, or both items if necessary.
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.
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
* Because of his massive AoE damage, Sand King is very effective against illusion heroes: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren.
Riki
* Heroes who are reliant on physical damage will be nullified by Decrepify: Riki, 
Wraith King, 
Juggernaut.
Riki
* Charge of Darkness provides shared vision over its target, keeping track of heroes who rely on invisibility, mobility, or illusions: Riki, 
Broodmother, Phantom Lancer
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.
Naga Siren
* Heroes who are reliant on illusions or summons: Chaos Knight, Broodmother, Naga Siren.
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.
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.
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 long cast animations can be continuously interrupted by Battery Assault: 
Centaur Warrunner, Jakiro, Leshrac, Naga Siren, Underlord.
Riki
* Riki doesn't deal burst damage.Durable heroes (
Axe, 
Tidehunter etc.) will usually survive a jump from him,move out of Smoke Screen and potentially retaliate.
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 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.
Riki
* Corrosive Haze makes Riki completely vulnerable to Slardar and his allies, as Riki has no easy way of dispelling it.
* Slardar's physical damage with Slithereen Crush and Bash of the Deep amplified by Corrosive Haze can easily kill Riki.
Additional:
* 
Corrosive Haze works much like 
Track, giving the enemy team vision over Riki. While it doesn't give a movement speed or gold bonus, it instead can melt Riki's armor and Slardar can use 
Guardian Sprint to catch up to him.
* Slardar's Aghanim's Shard, causes 
Slithereen Crush to apply Corrosive Haze even if Slardar does not have vision over him.
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.
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.
Riki
* Earthshaker must be careful not to use 
Blink Dagger or Aghanim's Scepter upgraded 
Enchant Totem to blink into Riki's Smoke Screen or 
Night Stalker's 
Crippling Fear, as these field effects will instantly silence Earthshaker and prevent him from initiating.
Riki
* Track reveals Riki while invisible and gives him a hard time, as it prevents much of his ganking capabilities. This can force Riki to buy Manta Style to dispel it.
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.
Riki
* Viper's 
Nethertoxin disables Cloak and Dagger, negating Riki's invisibility and much of his damage. It also makes him more vulnerable to magic damage, which does not go well with Riki's low health pool. With the talent applied, he can't even blink to safety or hide with Tricks of the Trade.
* 
Corrosive Skin makes it hard for Riki to chase Viper and attack him due to the attack speed slow.
* 
Viper Strike stays on Riki even after he goes invisible.
* 
Poison Attack makes it risky for Riki to get last hits and can make the laning phase difficult for him.
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.
Riki
* Blink Strike does not grant Riki a mobility advantage over Phantom Assassin, as her Phantom Strike serves the same purpose, but with a higher range.
* A Carry Riki usually has a hard time dealing with Blur, as a 
Monkey King Bar or 
Bloodthorn are unfavourable item picks for him (or, even more unlikely, a Silver Edge).
* A Black King Bar is a very common pick for Phantom Assassin, fully countering Smoke Screen and 
Diffusal Blade while activated.
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.
Riki
* Riki has high damage and invisibility, meaning he can easily gank Rubick and kill him before Rubick has the chance to react.
* Cloak and Dagger renders Riki invisible, which makes his spells hard to steal if not being initiated.
* Similar to Clinkz, Rubick has to buy a large amount of Sentry Wards to keep track of Riki due to Cloak and Dagger, preventing Rubick from getting better items.
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.
Riki
* Sniper has no natural escape and relies on his range and slows to keep himself safe, which Riki can bypass with Blink Strike and quickly deplete his miniature HP pool.
Naga Siren
* Ensnare with her attacks allows Naga Siren to gank Sniper easily.
* Rip Tide removes Sniper's very little armor.
Riki
* Chen is basically Riki's natural prey: he has little HP, low armor and relies on his persuaded creeps to fight, which in most situations will not save Chen from Riki. Just be wary of {U:Centaur Conqueror}, who can stun Riki outside of Smoke Screen and ruin his attempt at Chen's life.
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.
Riki
* Smoke Screen combined with Diffusal Blade leaves Arc Warden effectively useless for a while as he struggles to escape the silence with low mobility.
* With Arc Warden's low mobility, Tricks of the Trade often deal decent damage to him before he moves out of it.
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.
Riki
* Smoke Screen prevents Storm Spirit from using his abilities once inside the radius. Riki can utilize this ability to allow his team to fight around Smoke Screen so that Storm Spirit cannot spam his spells to proc 
Overload.
Additional:
* Smoke Cloud prevents Storm Spirit from using any of his offensive and defensive spells, rendering him unable to effectively react to Riki's attack.
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.
Riki
* Heroes with invisibility: (Riki, 
Clinkz, 
Nyx Assassin.
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.
Riki
* Lifestealer cannot use Rage, Infest or 
Open Wounds when affected by Smoke Cloud's silence, and 
Feast cannot heal him effectively because of the blind, leaving him very weak both offensively and defensively.
* Infest ganks are harder when the enemy team has a Riki, as there are often only four heroes on the map that you can initiate on.
Naga Siren
* Heroes with illusions: Chaos Knight, Naga Siren, Phantom Lancer, Terrorblade
Riki
* Heroes that can easily bypass Io's allies to get to Io: Riki, 
Tusk, Clinkz, 
Sniper, Slark, Phantom Assassin, 
Void Spirit, Storm Spirit, 
Ember Spirit, 
Earth Spirit, Spirit Breaker.
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.
Riki
* Riki is a natural Diffusal Blade carrier, and it doesn't help that he's easily capable of sneaking up on Wraith King due to Cloak and Dagger.
* Riki can use Smoke Screen on top of Wraith King as he is reincarnating, making him a sitting duck for his second life. In addition, the blind prevents Wraith King from landing critical hits from Mortal Strike.
* Wraithfire Blast is quite predictable, and if Riki can react fast, he will disjoint it with Tricks of the Trade. There is also a chance he will become invisible again as the projectile travels, disjointing it.
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.
Riki
* Riki: Smoke Screen can prevent Lone Druid from using True Form and Savage Roar, additionally it cause the spirit bear to miss on attacks which reduce the chances of getting rooted from it, with diffusal Blade, he can keep Lone Druid or the Spirit Bear inside the Smoke.
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.
Riki
* Frostbite will reveal invisible heroes for its duration, making it a good tool against any such hero (Riki, 
Bounty Hunter, Weaver, or Clinkz for example), or as a soft counter to 
Shadow Blade, if it is used first. This can be an amazing tool to ensure that Dust of Appearance is used on the unit in question, and not wasted in not catching anything.
Riki
* Smoke Screen effectively disables Crystal Maiden's channeling spell: 
Freezing Field.
* Due to her low health and armor throughout the game, Riki can kill her easily.
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.
Riki
* Riki with Tricks of the Trade
* 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
* 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
Riki
* Riki usually buys Diffusal Blade to initiate, which renders Enchantress' movement speed useless, and is usually followed with Smoke Screen.
* Riki can effectively hit Enchantress by Tricks of the Trade alongside with Diffusal Blade and Smoke Screen's initiation. For a hero like Enchantress, 3 to 4 hits from Riki is a big deal, unless Enchantress built 
Force Staff earlier.
Riki
* Heroes with high base damage (
Morphling, 
Tiny, 
Drow Ranger), heroes with mana burning abilities (
Anti-Mage), and Diffusal Blade users (Juggernaut or Riki) will suffer from Reflection's illusions.
Riki
* Heroes with abilities that can lock down Terrorblade and prevent him from using Sunder: 
Bane, 
Batrider, Earthshaker, Elder Titan, Faceless Void, 
Invoker, Legion Commander, 
Mars, 
Primal Beast, Riki, Shadow Shaman, 
Silencer, 
Vengeful Spirit, Void Spirit.
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.
Riki
* Blink Strike gets Riki close to Drow Ranger and disable Marksmanship.
* Cloak and Dagger allow Riki stay close to Drow Ranger without her noticing him, which allows him to disable Marksmanship.
Additional:
* With Blink Strike, Riki can get close to Drow Ranger and disable her 
Marksmanship, and Smoke Screen will prevent her from using 
Gust.
Riki
* Riki can detect early Roshan attempts because of Cloak and Dagger if he frequently checks the Pit.
* Ursa cannot Enrage when in Smoke Screen (Black King Bar will help though).
* Even if Ursa gets vision over him, Riki can Blink Strike away or use Tricks of the Trade after Ursa's initiation to avoid all 
Fury Swipes damage until 
Earthshock's slow is gone.
Additional:
* Riki can detect early Roshan attempts because of Cloak and Dagger if he frequently checks the Pit.
* Ursa cannot Enrage when caught in Smoke Screen and will miss his attacks (although Black King Bar will help with this issue).
* Even if Ursa gets vision over him and initiates with Earthshock, Riki can Blink Strike away or use Tricks of the Trade after Ursa's initiation to avoid Fury Swipes' damage until Earthshock's slow is gone.
Riki
* Smoke Cloud prevents Queen of Pain from using any of her offensive and defensive spells, rendering her unable to effectively react to Riki's attack.
* It's easy to dodge 
Sonic Wave by using Blink Strike & Tricks of the Trade.
Riki
* Smoke Cloud prevents 
Shukuchi and Time Lapse, leaving Weaver helpless against Riki.
* 
The Swarm is ineffective against Riki because invisibility instantly removes the beetles.
Riki
* Due to his low health and armor, Riki can easily kill Skywrath Mage.
* Smoke Screen prevents Skywrath from using all of his abilities, as he does not tend to buy Black King Bar.
* However, Skywrath Mage can easily kill Riki if he manages to root Riki with Rod of Atos or Gleipnir, followed by Dust of Appearance, Ancient Seal and Mystic Flare.
Riki
* Riki can get on top of Ancient Apparition very easily with Blink Strike. This can also double as a way to dodge Ice Blast, along with Tricks of the Trade.
* Ancient Apparition will frequently resort to casting Ice Blast right before dying. Smoke Screen can be used to prevent this, stopping Ancient Apparition from having any impact.
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.
Riki
* Riki is known for being a successful support killer, something Shadow Shaman is very vulnerable to.
* Smoke Screen is particularly devastating to Shadow Shaman. With neither his various disables nor a solid health pool Shadow Shaman is usually dead. This forces Shadow Shaman to buy a Force Staff if he finds himself in this scenario and buy 
Sentry Wards if you have the money.
Riki
* Smoke Cloud prevents the use of 
Death Pact, 
Searing Arrows and 
Skeleton Walk, so Clinkz can neither defend himself against Riki nor fight back effectively.
* It's hard to gank Riki as Clinkz has to find him first.
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.
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.
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.
Riki
* With Smoke Screen, Riki will silence and catch Medusa in a surprise with high miss chance flushing her from positions easily in team fights.
* He can deal a huge amount of damage through Cloak and Dagger, even through Mana Shield.
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.
Riki
* Frail heroes who lacks mobility: 
Crystal Maiden, Enigma, 
Dark Willow, Vengeful Spirit.
Additional:
* Smoke Screen prevents Dark Willow from using her abilities, rendering her defenseless and unable to deal any serious damage.
* Blink Strike lets Riki jump past Bramble Maze.
Riki
* Riki and 
Disruptor: Smoke Screen and 
Static Storm can be thrown wherever Puck used Phase Shift, making Puck an easy target if it doesn't have Blink Dagger or is on cooldown. Puck is also very susceptible to Riki's high attack damage when attacking from the back. Glimpse also prevents Puck from escaping.
Riki
* Heroes with a high degree of mobility and invisibility are hard to catch with Meat Hook: Ember Spirit, Riki, Clinkz, 
Queen of Pain.
Riki
* Heroes that have superior mobility that can easily catch up with Mirana even after she used Leap to escape: Anti-Mage, Queen of Pain, Storm Spirit, Riki.
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.
Riki
* Because Templar Assassin does not have escape potential in lane, any support hero with roaming potential and a Dust of Appearance can be great at shutting her down early game: Earth Spirit, Spirit Breaker, Tusk, Bounty Hunter, Riki, Warlock.
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.
Riki
* Riki is another good hero to shutdown Death Prophet with Diffusal Blade as his core item. His Smoke Screen stops her from initiating and casting spells.
Riki
* Heroes that can gank Shadow Fiend in the early game: Earth Spirit, Nyx Assassin, Riki, Spirit Breaker.
Riki
* Heroes with silence: 
Death Prophet, Riki, Drow Ranger.
Riki
* Frail heroes who lacks mobility: Crystal Maiden, Enigma, Dark Willow, Vengeful Spirit.
Riki
* Heroes with damage-increasing passive abilities, such as 
Viper and Riki, will usually kill Silencer in a short time before he even has time to set up his abilities.
Riki
* Warlock is a very strong hero when positioned correctly, and his long cast range helps him with this. However, some Heroes might disrupt or sneakily pass through his allies and deal with him, preventing him from doing his job. Such heroes include Chaos Knight, Spirit Breaker, Riki, and more.
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.
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.
Riki
* Heroes with abilities or items that can silence or disable Anti-Mage for long periods of time will prevent him from Blinking away: Lion, Silencer, Shadow Shaman, 
Grimstroke, Witch Doctor, Riki, Faceless Void, 
Skywrath Mage, Puck.
Additional:
* Anti-Mage can use neither 
Blink nor Manta Style to escape from Smoke Cloud.
* Even if he activates a Black King Bar, his Manta Style illusions will still be blinded by Smoke Cloud.
* Riki has a very small mana pool and generally doesn't buy many items that increase it, making 
Mana Void ineffective.
Naga Siren
* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother
Riki
* Heroes who rely on their target to run away: Riki, Bounty Hunter.
Riki
* 
Bulwark is generally irrelevant against Riki as he primarily deals bonus damage from behind.
Additional:
* Blink Strike gives bonus backstab damage and can bypass Bulwark. Defensively, it could be used to teleport away from Mars, especially while inside Arena of Blood.
* Smoke Screen can interrupt Mars' skill combos, especially when cast inside Arena of Blood.
* Tricks of the Trade can be used to evade Mars' skills, which have a slight delay to them. It could also be used to buy himself time while trapped inside of Arena of Blood.
Naga Siren
* Heroes who depends on illusions and summons: Naga Siren, Arc Warden, Broodmother will struggle against Great Cleave.
Riki
* Cloak and Dagger makes Sven unable to detect where Riki is until he shows or his team provides detection.
* Smoke Screen will make Sven miss attacks before he has his Black King Bar.
Naga Siren
* Sand King and Phoenix have many tools to deal with multiple enemies at once, which will work well against a crowd of illusions.
Naga Siren
* Song of the Siren does not affect Supernova, which allows her and her team to focus the egg while the enemy team is affected by sleep.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
Riki
* Without Dust of Appearance or Sentry Wards, Riki is able to silence Witch Doctor with Smoke Screen, and is likely to build a Diffusal Blade, leaving Witch Doctor without mana to cast Voodoo Restoration, as well as Skull Basher to interrupt Death Ward.
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.
Riki
* Heroes with escaping and disjointing abilities can be good against Juggernaut:Anti-Mage Riki, Queen of Pain, Puck, Storm Spirit, Ember Spirit, Slark etc.
Naga Siren
* Illusion-based heroes are effective against Omnislash and Juggernaut's single-targeted damage: Naga Siren, Chaos Knight, Terrorblade,Phantom Lancer.
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
Riki
* Techies is very good against roaming supports and gankers such as Bounty Hunter, Riki, Weaver, Earthshaker, Nyx Assassin, etc. that are constantly moving around the map.
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
* 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.
Riki
* Frail heroes who lacks mobility: Crystal Maiden, Enigma, Dark Willow, Vengeful Spirit.
Additional:
* Riki can potentially catch an Enigma out of position and prevent him from properly blinking and initiating, thanks to Cloak and Dagger.
* Before Enigma gets his Black King Bar, Smoke Screen can be used to cancel Black Hole. After Enigma gets Black King Bar, Riki can also cancel Black Hole with Abyssal Blade, which is a common item built on him.
* Tricks of the Trade renders Riki hidden and invulnerable, which in combination with Abyssal Blade allows Riki to cancel Black Hole with little to no worries of getting caught in it.
* Enigma's fragility during all stages of the game makes him extremely prone to Riki's ganking.
Riki
* In general, heroes who are melee with no way to fight back can be very easily poked by Monkey King to gain his Jingu Mastery stacks: 
Dark Seer, Riki, 
Rubick.
Riki
* Heroes with blind of some sort can be a bad choice for Monkey King to go on: Broodmother, Riki, 
Keeper of the Light.
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.
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
Riki
* Heroes with silences: Puck, Doom, Riki.
Riki
* Another great threat to Riki since her 
Duel forces him to fight from the front and expose him for the entire duration, almost always guaranteeing an easy win (unless Riki has allies helping him).
* 
Moment of Courage can become hard to deal with as it doesn't cease with silence.
Naga Siren
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, Chaos Knight, Terrorblade, Naga Siren
Riki
* Heroes with abilities that blind or cause Legion Commander to miss will prevent her from winning Duels: Arc Warden, Keeper of the Light, Riki, 
Tinker
Naga Siren
* Song of the Siren lasts long enough to prevent a successful Duel (but only if Naga wasn't the target).
Riki
* 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.
Riki
* Heroes who rely on invisibility, such as Bounty Hunter, Clinkz, Mirana, Nyx Assassin and Riki, as they will be revealed if caught by Chronosphere.
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.
Riki
* Riki takes a lot of damage from 
Purification while ganking Omniknight's allies or himself.
* Heavenly Grace instantly purges the slow from Diffusal Blade, while also providing a large amount of survivability for his victim.
* 
Degen Aura can hinder Riki's positioning tactics and put a heavy toll on Riki's already poor movement speed.
* Omniknight can easily save his allies by using 
Guardian Angel in combat.
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
* 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.
Riki
* Low-health, normally mobile carries with a lot of damage are vulnerable to Bane's nukes and disables: Anti-Mage, Clinkz, Drow Ranger, Faceless Void, Gyrocopter, Juggernaut, Luna, Meepo, Mirana, Monkey King, Morphling, Phantom Assassin, Phantom Lancer, Riki, 
Shadow Fiend, Slark, Sniper, Terrorblade, 
Troll Warlord, Weaver.
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.
Riki
* With Dark Ascension and Gem of True Sight, Night Stalker can easily find and kill Riki. Riki will also find it harder to kill the tanky Night Stalker than he would many other heroes.
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.
Riki
* Any hero with a low HP pool is easy for Tinker to nuke down: Crystal Maiden, Enchantress, Gyrocopter, Lion, Riki, 
Techies, Terrorblade, 
Necrophos, Invoker.
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.
Riki
* 
Spectral Dagger follows Riki even after he goes invisible and stays on him through Tricks of the Trade, revealing his location.
* 
Desolate grants Spectre the ability to damage Riki with right clicks regardless of Smoke Screen's blind.
* Riki relies on his high damage to kill is opponents, which is countered by 
Dispersion.
* 
Haunt can find Riki globally at any time, negating much of his ganking potential.
Riki
* Riki's Smoke Screen can make it hard for Spectre to escape or burst down Riki with auto attacks.
* Riki can build Aghanim's Scepter and jump inside an allied carry or offlane tank with Tricks of the Trade to do a lot of damage to Spectre while completely avoiding Dispersion.
* Riki is great at destroying supports which are often needed to keep Spectre safe until she comes online. He can take them down quickly in team fights, which will leave Spectre alone against your whole team, a fight that she will most likely not win.
* While on Tricks of the Trade, Riki does not take damage from Dispersion.
Riki
* Riki can easily be caught in an Ice Path and Macropyre combo as he finishes
Tricks of the Trade, Jakiro just has to be careful about Riki's 
Smoke Screen when dealing with Riki.
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.
Black King Bar, and that makes her very vulnerable to Jakiro's damage over time in every phase of the game.
Song of the Siren.
Black King Bar, this can make her very vulnerable to Jakiro's damage over time in every phase of the game.
* Naga Siren is not a hero that likes to go for
Additional:
* Jakiro's damage over time abilities can clear Naga Siren's illusions and can hurt real Naga Siren even for the duration of
* Since Naga Siren is a hero who barely goes for