Lina
* Heroes with low mobility that rely on spells: 
Zeus, 
Lina, 
Crystal Maiden.
Keeper of the Light
* 
Crippling Fear prevents Keeper of the Light from using his spells to keep his team alive during team-fights.
* 
Dark Ascension is very strong against Keeper of the Light, as it allows Night Stalker to jump the backline and quickly kill the squishy Ezalor, especially when combined with the slow from 
Void.
Additional:
* Keeper of the Light's 
Aghanim's Scepter upgrade loses much of its power, due to Night Stalker being able to reduce the duration of daytime by a lot.
Lina
* Heroes who have most or all their abilities (damage or disable) unable to pierce spell immunity: 
Keeper of the Light, Lina, 
Lion, Zeus.
Additional:
* 
Rage protects Lifestealer from all of Lina's abilities. However, Lina can paritally counter this if played as Carry, a common role for Lina.
* 
Open Wounds from 
Aghanim's Shard can severely slow down Lina and allow Lifestealer and his allies to recover themselves by attacking her.
* Aghanim's Scepter upgraded 
Infest can be used to disarm Lina even if she is spell immune, rendering her unable to maximize the effect of her 
Fiery Soul and force her to use her abilities more often than intended. And Lina's only way to counter this is with 
Linken's Sphere
Keeper of the Light
* Rage allows him to be immune to all of Ezalor's abilities. Also, the increased movement speed combined with the slow from 
Ghoul Frenzy and the squishy nature of Ezalor allows Lifestealer to take him down very quickly.
Lina
* Nether Ward will be problematic for heavy nukers and spammers like 
Skywrath Mage, Lina, Lion and 
Invoker, but Pugna must not use Decrepify defensively against them as he will be helping them out more than anything.
Keeper of the Light
* Pugna easily copes on the line with the Keeper of the Light push with his 
Nether Blast, and in addition to 
Nether Ward, the Keeper of the Light is not able to throw 
Illuminate on creeps for a long time, so Pugna earns more gold and a level on the line
Additional:
* Pugna easily copes on the line with the Keeper of the Light push with his Nether Blast, and in addition to Nether Ward, the Keeper of the Light is not able to throw Illuminate on creeps for a long time, so Pugna earns more gold and a level on the line
Lina
* Templar Assassin can outmatch Lina on the center line thanks to her own 
Psi Blades, which is why the advantage of Lina's long-range attacks become turned against her.
* 
Refraction is good defense against Lina's burst damage. But remember that Lina can partially counter this with 
Dragon Slave's damage over time.
Additional:
* Outlanes Lina on the center line thanks to her own Psi Blades, which is why the advantage of Lina's long-range attacks become turned against her
* Closes from Lina's magic attacks with her own Refraction, which is why Lina can't make her combination: 
Light Strike Array, Dragon Slave, 
Laguna Blade and kill Templar Assassin quickly
Keeper of the Light
* Heroes that can jump and kill him: 
Meepo, 
Clinkz, 
Templar Assassin
Lina
* 
Mind Flare does tons of damage against Lina because of her high intelligence.
* 
Vendetta can deal heavy damage to Lina while also burning her mana, preventing Lina from casting her abilities.
* 
Spiked Carapace can easily be used to counter Lina's abilities because of their long cast animation, and could probably kill Lina outright if Laguna Blade is reflected. However, Lina can counter this with 
Eul's Scepter of Divinity, a common item on Lina.
Keeper of the Light
* Spiked Carapace can be used to reflect Illuminate damage and stun Keeper of the Light.
* Vendetta allows Nyx Assassin to follow Keeper of the Light around if he tries to split-push.
* Keeper of the Light is very squishy and will very quickly die to Vendetta and it's followup abilities.
Lina
* Heroes who build 
Black King Bar as either core or situational item will be able to fight back against Nyx Assassin and freely attack him as Spiked Carapace cannot pierce spell immunity at all: 
Axe, 
Broodmother, 
Dawnbreaker, 
Enigma, 
Huskar, 
Jakiro, 
Legion Commander, Lina, 
Luna, 
Lycan, 
Slardar, 
Slark, 
Troll Warlord, 
Witch Doctor.
Lina
* 
Blink allows Anti-Mage to get on top of Lina and deal damage with his 
Mana Break.
* 
Counterspell makes Anti-Mage tanky against Lina's heavy magic damage. It can also be used block and reflect Laguna Blade.
* 
Mana Void is very hazardous for Lina, who has a high mana pool and quickly depletes it during fights.
Keeper of the Light
* Being an intelligence caster hero, Ezalor usually has a high mana pool and low health and armor, making him a prime target for Mana Void
* Ezalor's Illuminate damage and Solar Bind's magic resistance reduction are greatly reduced thanks to Counterspell. Counterspell can also block and reflect Solar Bind if timed properly.
* Anti-Mage usually is not hampered by Solar Bind or Will-O-Wisp thanks to Blink.
* However, despite all of this, if Keeper of the Light is played carefully and tops off his team's mana at all times, Anti Mage will not be able to get off a good Mana Void.
* By the same token once Keeper of the Light gets a 
Octarine Core, he can spam Charka Magic to keep his own mana ful
Keeper of the Light
* 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
Lina
* Light Strike Array has a long delay, making her vulnerable for Ursa's burst.
* Enrage can protect Ursa against Lina's high magical burst.
Lina
* Ember Spirit absorbs quite a large amount of magical damage with its 
Flame Guard, and in addition dodges the abilities of Dragon Slave and Light Strike Array with its 
Sleight of Fist
Additional:
* Ember Spirit absorbs quite a large amount of magical damage with its Flame Guard, and in addition dodges the abilities of Dragon Slave and Light Strike Array with its Sleight of Fist.
Keeper of the Light
* 
Blood Rite makes Ezalor chose between getting off Illuminate or getting silenced for a while, as Illuminate is a channeled ability.
* Blood Rite's silence can completely take Ezalor out of a teamfight, as he relies on his abilities to be useful.
* Keeper of the Light's only mobility source, his high movement speed (via his high base movement speed and through spirit form), is entirely countered by 
Rupture.
Lina
* Heroes with spell immunity unless Lina chooses to play Carry role like 
Lifestealer with Rage and 
Juggernaut with 
Blade Fury.
Keeper of the Light
* Juggernaut's 
Healing Ward keeps his team healthy even when pushing against Keeper of the Light's Illuminate.
* Blade Fury can dispel 
Blinding Light, as well as dodge an incoming Illuminate. Juggernaut can attack towers during Blade Fury, so he can dodge an Illuminate without having to stop pushing.
* Should Keeper of the Light obtain 
Will-o-Wisp through purchasing an Aghanim's Scepter, Juggernaut can make quick work of Ignis Fatuus without being interrupted by its pull.
* Keeper of the Light has low health, low armor, and no natural defense against Blade Fury.
Additional:
* Blade Fury allows him to be immune to all of Ezalor's abilities.
* Healing Ward heals his entire team, mitigating Ezalor's weak magical burst damage.
Keeper of the Light
* Keeper of the Light's Blinding Light makes Juggernaut miss his attacks. However, it can be dispelled easily with Blade Fury.
Lina
* Dragon Slave is easy to steal, and provides Rubick with a useful nuke.
* Light Strike Array serves as a cheap nuke as well as a crowd control ability.
* Rubick uses the fixed 0.15 second cast time when casting Light Strike Array, much faster than Lina herself.
* Rubick can gurantee a stun by throwing the victim into the area with 
Telekinesis, extending the overall lockdown duration.
* Laguna Blade is an awesome ultimate that gives huge burst damage.
* 
Arcane Supremacy (combined with Level 25 talent +40% Spell Amp For Stolen Spells, as of 7.31c) increases its damage before reduction to a whopping 660/882/1134(830/1162/1494) (and even more so with Aghanim's Scepter), without considering spell amplification from items.
* Laguna Blade is an intelligence hero with no regen ability, and casting Laguna Blade back to Lina can result in her unexpected sudden death, or severly hinder her presence in the rest of teamfight. Nevertheless, the skill can also be cast on other squishy heroes or help bursting down enemy carries.
* Light Strike Array and Laguna Blade has a short cast range, and Rubick can extend its range thanks to Arcane Supremacy.
Lina
* 
Spectral Dagger and 
Haunt allow Spectre to get close to Lina.
* 
Desolate is very strong against Lina, who's usually a bit isolated in fights because of her high attack and cast range.
* 
Dispersion can mitigate a good portion of Lina's burst damage, allowing Spectre to turn on her afterwards.
Additional:
* Spectre can very easily close the distance on Lina with Haunt and Spectral Dagger, and due to Lina's abysmal mobility without a 
Blink Dagger and terrible health pool and armor, Lina easily gets slaughtered due Desolate.
* Dispersion can mitigate a good portion of Lina's burst damage, allowing Spectre to turn against her afterwards.
Lina
* Puck can dodge Lina's Dragon Slave and Light Strike Array with his 
Phase Shift skill, which helps him avoid combining these abilities with Laguna Blade and avoid burst damage from Lina.
* Puck forbids Lina to use her abilities with the 
Waning Rift ability, which will help her teammates survive and even give them the opportunity to kill her.
Additional:
* Puck can dodge Lina's Dragon Slave and Light Strike Array with Phase Shift. A good Puck player can even dodge Laguna Blade, as it has an invisible projectile, therefore avoiding all the burst damage from Lina.
* Puck forbids Lina to use her abilities with Waning Rift, which will help Puck's teammates survive and even give them the opportunity to kill her.
Keeper of the Light
* Heroes with silences: 
Puck, 
Doom, 
Riki.
Keeper of the Light
* Heroes who are strong against mobile heroes: 
Disruptor, 
Bloodseeker, 
Kunkka, Keeper of the Light.
Lina
* 
Doppelganger can be used to easily dodge Light Strike Array if timed correctly.
* While Lina can clear Phantom Lancer's illusions with her abilities, Phantom Lancer can quickly deplete Lina's mana pool with his illusions and deal massive damage from it simultaneously since Phantom Lancer is a natural 
Diffusal Blade carrier.
Keeper of the Light
* Heroes with dispels: Legion Commander, 
Oracle, Slark, 
Phantom Lancer
Lina
* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, Nature's Prophet, 
Chen, Terrorblade, Naga Siren, 
Visage, 
Wraith King, Lycan, Phantom Lancer, 
Shadow Shaman.
Keeper of the Light
* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer
Keeper of the Light
* Heroes with hastes: 
Dark Seer, Lycan
Lina
* Marci can be effective against vulnerable squishy heroes that cannot deal with heroes that jump onto them - 
Sniper, 
Drow Ranger, Lina, 
Rubick, etc.
Lina
* Squishy heroes (
Io, Crystal Maiden, Lina...), as Earth Spirit can deal tons of damage with Magnetize.
Keeper of the Light
* Jakiro's reliance on his abilities can cause struggles for heroes who rely on evasion or blinds to get upper hand: 
Phantom Assassin, 
Windranger, Riki, Troll Warlord, Keeper of the Light.
Keeper of the Light
* Heroes with silences: Puck, Doom, Riki.
Keeper of the Light
* Any hero who lanes very poorly will struggle with Primal Beast's potential snowball in the very early levels, like Keeper of the Light, Luna, Templar Assassin...
Lina
* Storm Spirit can quickly close the distance with Lina using 
Ball Lightning. In addition, Ball Lightning can be used as a way to dodge the abilities of Dragon Slave and Light Strike Array
Additional:
* Storm Spirit can quickly close the distance with Lina using Ball Lightning. In addition, Ball Lightning can be used as a way to dodge the abilities of Dragon Slave and Light Strike Array
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, 
Queen of Pain, 
Storm Spirit
Lina
* Lina can win on a line against Storm Spirit because of the range of her abilities and attacks, and Storm Spirit will be forced to survive on such a line, not farm
Keeper of the Light
* 
Finger of Death can instantly shred many targets, especially fragile Heroes like Keeper of the Light, 
Ancient Apparition or 
Bounty Hunter.
Keeper of the Light
* Squishy heroes, usually supports, like Lion, Ancient Apparition, Keeper of the Light etc can die quickly to Tiny's magic burst.
Lina
* Heroes with long animations can be frequently interrupted with Cold Snap: 
Earthshaker, 
Monkey King, 
Shadow Fiend Lina
Keeper of the Light
* Heroes with silences: Puck, Doom, Riki.
Lina
* Heroes with abilities that can pull Lina out of position can easily bring her to their team mates, like 
Batrider with 
Flaming Lasso, 
Pudge with 
Meat Hook and 
Vengeful Spirit with 
Nether Swap.
Lina
* Sven has a high health pool and is a natural Black King Bar holder and is very hard to kill for Lina.
* Sven also has high physical damage, making it easy for him to burst her down.
Keeper of the Light
* Melee carries during the laning phase: 
Sven, Slark
Keeper of the Light
* 
Press the Attack can dispel Blinding Light or Solar Bind from a hero.
* 
Duel can be used to instantly take Keeper of the Light out of a team-fight.
Keeper of the Light
* 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
Lina
* 
Dark Pact can be cast during the cast animation of Light Strike Array and dispel its stun.
* 
Pounce allows Slark to close the gap to Lina.
* 
Shadow Dance prevents Lina from killing Slark with her Laguna Blade when his HP gets low.
Keeper of the Light
* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer
Lina
* Heroes with heavy magical nukes will take advantage of Slark's poor HP or force him to use Shadow Dance early: Lina, Lion, Zeus
Keeper of the Light
* Melee carries during the laning phase: Sven, Slark
Lina
* 
Time Walk will easily backtrack Lina's burst damage (especially Laguna Blade) if not timed correctly.
* During 
Chronosphere, squishy heroes like Lina will be main target of Faceless Void in his ultimate.
Keeper of the Light
* Any hero that can nullify effects of Chronosphere: (Keeper of the Light with Aghanim's Scepter during daytime, 
Winter Wyvern), banishing him or Faceless Void (
Outworld Destroyer, 
Shadow Demon, 
Earth Spirit with Aghanim's Scepter) or protecting him in other ways (
Dazzle, Oracle, 
Abaddon) can greatly limit Chronosphere's potential.
Lina
* 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.
Keeper of the Light
* Illuminate wipes out Broodmother's spiders and prevents her from pushing the lane. It also gives vision to reveal where broodmother is hiding in the trees.
Lina
* 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.
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.
Keeper of the Light
* Heroes with summons/illusions/neutral creep armies: 
Beastmaster, Chen, Naga Siren
Lina
* Laguna Blade is one of the best tools to kill Terrorblade before he can use 
Sunder due to its high magical damage.
* Dragon Slave and Light Strike Array allows Lina to clear Terrorblade's illusions from both, Conjure Image and 
Manta Style.
* Lina commonly buys items that allow her attacks to deal magical damage to Terrorblade that can ignore his high armor, like 
Gleipnir, 
Monkey King Bar or 
Revenant's Brooch.
Additional:
* Laguna Blade is one of the best tools to kill Terrorblade before he can use Sunder due to its high magical (pure with Laguna Blade damage is Pure and pierces Spell Immunity talent) burst damage.
* Dragon Slave and Light Strike Array allows Lina to clear Terrorblade's illusions from both, Conjure Image and Manta Style.
Keeper of the Light
* 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
Lina
* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, Nature's Prophet, Chen, Terrorblade, Naga Siren, Visage, Wraith King, Lycan, Phantom Lancer, Shadow Shaman.
Keeper of the Light
* 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
Lina
* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: Sven, 
Omniknight, Enigma, Luna, Naga Siren, 
Mars, Jakiro, 
Venomancer, 
Elder Titan, 
Faceless Void, Rubick, Keeper of the Light, 
Pugna, Invoker, 
Spectre, 
Alchemist, 
Treant Protector, Lina, Oracle, Zeus, Shadow Shaman, 
Phoenix, 
Razor, Huskar, Batrider, Kunkka, 
Tidehunter, Wraith King, 
Sand King, 
Medusa, Dawnbreaker.
Keeper of the Light
* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: Sven, Omniknight, Enigma, Luna, Naga Siren, Mars, Jakiro, Venomancer, Elder Titan, Faceless Void, Rubick, Keeper of the Light, Pugna, Invoker, Spectre, Alchemist, Treant Protector, Lina, Oracle, Zeus, Shadow Shaman, Phoenix, Razor, Huskar, Batrider, Kunkka, Tidehunter, Wraith King, Sand King, Medusa, Dawnbreaker.
Lina
* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, Nature's Prophet, Chen, Terrorblade, Naga Siren, Visage, Wraith King, Lycan, Phantom Lancer, Shadow Shaman.
Additional:
* Lina can easily prevent Nature's Prophet's Teleportation escape attempts with Light Strike Array, and can clear Sprout's trees instantly.
* Lina's Dragon Slave and Light Strike Array can kill Nature's Prophet's Treants.
Keeper of the Light
* 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
Lina
* Heroes who rely on armor or evasion to survive can easily be bursted down, like Phantom Assassin, Terrorblade, 
Underlord, 
Spirit Breaker.
Keeper of the Light
* Heroes that punish mobile heroes: Bloodseeker, Keeper of the Light, Kunkka, Disruptor.
Lina
* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, Nature's Prophet, Chen, Terrorblade, Naga Siren, Visage, Wraith King, Lycan, Phantom Lancer, Shadow Shaman.
Keeper of the Light
* Heroes which rely exclusively on right clicks will struggle somewhat against Blinding Light: Phantom Assassin, Wraith King, Medusa
Keeper of the Light
* Illuminate clears Beastmaster's summons and is effective against his push.
Lina
* 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).
Keeper of the Light
* Blinding Light can knock Monkey King outside of his ultimate, Wukong's Command and can blind him.
* Will-O-Wisp will stun Monkey King from Tree Dance by destroying his tree.
Additional:
* Blinding Light can easily push Monkey King out of Wukong's Command, as well as blinding him.
* Monkey King is vulnerable to burst damage, 
Solar Bind makes him more so
* However, Keeper of the Light can be easily ganked by Monkey King during early-mid game stage.
Lina
* 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.
Lina
* Enchantress has a very small health pool and cannot tank Lina's heavy magic burst.
* Untouchable is decently countered by Fiery Soul, exposing Enchantress's weakness to physical damage due to her low armor.
* Lina is decent at clearing creeps and can kill Enchantress's creeps quickly.
Additional:
* Enchantress has pitiful health, and cannot tank Lina's heavy magic damage.
* 
Untouchable is decently countered by Fiery Soul, exposing Enchantress's weakness to physical damage due to her low armor.
* Lina is decent at clearing creeps and can kill Enchantress' creeps quickly.
Lina
* 
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.
Additional:
* Eul's Scepter of Divinity is an item Lina commonly buys, which in combination with and Light Strike Array can disable Mirana if she tries to Leap away.
* Laguna Blade's magical (pure with Laguna Blade damage is Pure and pierces Spell Immunity talent) burst damage takes advantage of Mirana's below average health.
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.
Lina
* Laguna Blade ends Gyrocopter very quickly in the early to mid game.
Lina
* Lina defeats Sniper on the mid, because she has the same attack range as him, and her Dragon Slave ability deals much more damage to creeps, as well as to Sniper himself, than 
Shrapnel, which creates uncomfortable conditions for Sniper to farm on the line, which is why Lina either punches Sniper harder than he either pushes a pack of creeps up to the tower and finishes off his creeps under it, preventing Sniper from earning gold and a level.
Additional:
* Lina defeats Sniper on the mid, because she has the same attack range as him, and her Dragon Slave ability deals much more damage to creeps, as well as to Sniper himself, than Shrapnel, which creates uncomfortable conditions for Sniper to farm on the line, which is why Lina either punches Sniper harder than he either pushes a pack of creeps up to the tower and finishes off his creeps under it, preventing Sniper from earning gold and a level.
Lina
* 
Ghost Shroud is not a good defensive ability against Lina as all of her abilities deal magical damage.
* Lina has a very long range of attack, which completely overlaps the range of 
Death Pulse and 
Heartstopper Aura.
* However, once Necrophos gets Aghanim's Shard, he will gain access to 
Death Seeker which will allow him to turn into a larger Death Pulse that can be used to close the gap on Lina and kill her if she is not careful.
Additional:
* Laguna Blade's damage as well as damage from all of Lina's abilities will be greatly amplified during Ghost Shroud.
Lina
* Lina has very high magic burst damage to use against the low-health-pool Luna. Laguna Blade can also be upgraded with Laguna Blade damage is Pure and pierces Spell Immunity to bypass Black King Bar, making Lina even more of a threat. Luna however, can easily counter this problem with Linken's Sphere, which is a common item for her.
* For the same reasons, Lina makes a very powerful ally for Luna when they are in the same team.
Lina
* Lina can outlanes Shadow Fiend on the central line, due to the fact that Lina's attack range exceeds the attack range of Shadow Fiend, which makes it difficult for him to fend off her attacks and approach creeps, thus Lina has more level and gold.
* Lina can defeat Shadow Fiend with the combination of her abilities on lane and during teamfights: Light Strike Array, Dragon Slave, Laguna Blade, Shadow Fiend does not have a large pool of health before buying items for extra strength and health like 
Satanic, which is why Lina's strong magic damage is enough to kill him quickly.
Additional:
* Outlanes Shadow Fiend on the central line, due to the fact that Lina's attack range exceeds the range of Shadow Fiend, which makes it difficult for him to fend off her attacks and approach creeps, thus Lina has more level and gold
* Defeats Shadow Fiend` from Burst with a combination of skills: Light Strike Array, Dragon Slave, Laguna Blade, Shadow Fiend does not have a large pool of health before buying an item: Satanic , which is why Lina's strong magic damage is enough to kill him quickly
Lina
* 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
* 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.
* 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.
Keeper of the Light
* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.
Lina
* Heroes who can clear the waves of Enigma's Eidolons: Lina, Luna, Dawnbreaker, Jakiro, Shadow Shaman, 
Death Prophet, Keeper of the Light, Invoker, 
Leshrac, Puck.
Keeper of the Light
* Illuminate can wipe the pushing Eidolons in a lane with ease, diminishing Enigma's laning presence by a lot.
* Solar Bind will severely slow down Enigma and make him more vulnerable to magical damage more he moves for it's duration.
* However, Keeper of the Light does not have any way to cancel 
Black Hole outside from Will-O-Wisp provided by Aghanim's Scepter.
Lina
* 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 bypass 
Living Armor's protection.
Lina
* 
Guardian Angel is generally useless against Lina as she primarily relies on magical damage. Lina can also dispel it with Eul's Scepter of Divinity as she is a hero who often goes for it. Eul's Scepter of Divinity can later be upgraded into 
Wind Waker, which will allow Lina to escape from Omniknight.
* Laguna Blade can often finish off Omniknight's allies before he can save them with 
Purification and 
Repel. This can become even worse once Lina picks Laguna Blade damage is pure and pierces spell immunity talent, which will allow it to ignore both, any form of spell immunity and Guardian Angel.
Lina
* Heroes with high physical and magical damage alike are a huge hazard for Muerta, as they can deal serious damage to her even if she has 
Pierce the Veil active: Luna, Lina, 
Tusk, Broodmother, Shadow Fiend, 
Ember Spirit, 
Gyrocopter, Vengeful Spirit, Arc Warden, Medusa, Shadow Shaman.
Keeper of the Light
* Certain heroes can mess up with Pangolier's positioning and timing (especially if he intends to use Rolling Thunder during combat): Vengeful Spirit, Keeper of the Light, Huskar, Dark Seer
Lina
* Heroes with powerful spammable abilities will prove problematic for Grimstroke as Ink Swell does not protect him from them: Zeus, Skywrath Mage, Tinker, Lina
Lina
* Abilities that can destroy trees can give Hoodwink a disadvantage: 
Timbersaw, Windranger, Lina.
Lina
* Heroes with high burst damage through their physical attacks or spells can kill Dazzle or his allies before he has a chance to use Shallow Grave. (Lina, Lion, etc.)
Additional:
* Laguna Blade can kill Dazzle quickly before he casts 
Shallow Grave.
Keeper of the Light
* Heroes with hastes: Dark Seer, Lycan
Lina
* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, Nature's Prophet, Chen, Terrorblade, Naga Siren, Visage, Wraith King, Lycan, Phantom Lancer, Shadow Shaman.
Keeper of the Light
* Keeper of the Light has a blind, which causes Lycan to miss his attacks.
Lina
* 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.
Lina
* 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.
Lina
* Heroes with either magical, physical or pure damage burst: 
Bane, Ember Spirit, Leshrac, Lina, Luna, 
Nyx Assassin, Phantom Assassin, Skywrath Mage, Tinker, 
Ursa, 
Void Spirit.
Lina
* 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.
Lina
* Heroes who have channeled abilities can be stunned by Light Strike Array, like Witch Doctor with 
Death Ward and Bane's 
Fiend's Grip.
Lina
* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, Nature's Prophet, Chen, Terrorblade, Naga Siren, Visage, Wraith King, Lycan, Phantom Lancer, Shadow Shaman.
Lina
* Heavy nukers will do well against Cold Embrace (Lina, Zeus etc).
Lina
* Heroes who rely on armor or evasion to survive can easily be bursted down, like Phantom Assassin, Terrorblade, Underlord, Spirit Breaker.
Lina
* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, Nature's Prophet, Chen, Terrorblade, Naga Siren, Visage, Wraith King, Lycan, Phantom Lancer, Shadow Shaman.
Keeper of the Light
* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.
Lina
* 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.
Keeper of the Light
* Vulnerable spellcasters with no escape mechanisms are easy targets for Huskar: 
Lich, Crystal Maiden, 
Silencer, Keeper of the Light, Venomancer, etc.
Lina
* Lina interrupts Huskar on the center line because of her attack range, she can constantly be at a long distance, punching Huskar with her hand, while Huskar needs a very close distance to use 
Burning Spear
Additional:
* Lina can interrupt Huskar on the center line because of her attack range, she can constantly be at a long distance, punching Huskar with her hand, while Huskar needs a very close distance to use Burning Spear.
Lina
* Heroes with abilities that can pull Lina out of position can easily bring her to their team mates, like Batrider with Flaming Lasso, Pudge with Meat Hook and Vengeful Spirit with Nether Swap.
Lina
* 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.
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
Lina
* Lina has a very long range of attack, which completely overlaps the range of Queen of Pain's abilities and attacks, which is why even a single 
Shadow Strike roll can become deplorable, since Lina will shoot Queen of Pain from a long distance before and after the Shadow Strike roll. And with the help of the abilities of Light Strike Array and Laguna Blade, Lina can even kill Queen of Pain because of her small health reserve if she is exposed to a blow
Additional:
* Lina has a very long range of attack, which completely overlaps the range of Queen of Pain's abilities and attacks, which is why even a single Shadow Strike roll can become deplorable, since Lina will shoot Queen of Pain from a long distance before and after the Shadow Strike roll. And with the help of Light Strike Array and Laguna Blade, Lina can even kill Queen of Pain because of her small health reserve if she is exposed to a blow.
Lina
* Fragile support heroes are all ideal targets for the Phantom Assassin. Heroes such as Lina and Witch Doctor are all prime targets that may not be able to react quickly and fight back due to Phantom Assassin's sudden appearance.
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
Lina
* Laguna Blade is one of the best tools to kill Phantom Assassin before she can do anything in early-to-mid game due to its high magical (pure with Laguna Blade damage is Pure and pierces Spell Immunity talent) burst damage.
* 
Blur offers no protection against Lina's abilities. Likewise, Lina can counter Blur's evasion by buying either Silver Edge or Monkey King Bar.
* Lina just has to be careful about 
Fan of Knives from Aghanim's Shard and 
Coup De Grace, as Fan of Knives can deal pure damage to Lina and disable Fiery Soul awhile Coup De Grace can deal serious damage to her even if she is spell immune, which may force Lina to buy 
Ethereal Blade to deal with Phantom Assassin.
Additional:
* Laguna Blade is one of the best tools to kill Phantom Assassin before she can do anything in early-to-mid game due to its high magical (pure with Laguna Blade damage is Pure and pierces Spell Immunity talent) burst damage.
* Blur offers no protection against Lina's abilities. Likewise, Lina can counter Blur's evasion by buying either Silver Edge or Monkey King Bar.
* Lina just has to be careful about Fan of Knives from Aghanim's Shard and Coup De Grace, as Fan of Knives can deal pure damage to Lina and disable Fiery Soul awhile Coup De Grace can deal serious damage to her even if she is spell immune, which may force Lina to buy Ethereal Blade to deal with Phantom Assassin.
Keeper of the Light
* Heroes which rely exclusively on right clicks will struggle somewhat against Blinding Light: Phantom Assassin, Wraith King, Medusa
Keeper of the Light
* Heroes that can jump and kill him: Meepo, Clinkz, Templar Assassin
Lina
* Light Strike Array can catch Meepo and his clones off-guard if he tries to gank Lina with 
Earthbind & 
Poof.
* Laguna Blade can quickly kill Meepo and his clones before they escape with Poof.
Keeper of the Light
* With 
Bloodthorn, Clinkz becomes a strong counter to heroes who rely on evasion and blind such as Windranger, Phantom Assassin, Troll Warlord and Keeper of the Light.
Lina
* 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.
Lina
* Heroes with abilities that can pull Lina out of position can easily bring her to their team mates, like Batrider with Flaming Lasso, Pudge with Meat Hook and Vengeful Spirit with Nether Swap.
Lina
* 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.
Lina
* Both Lion's Finger of Death and Lina's Laguna Blade have a 0.25 second delay before the damage is dealt.
Lina
* 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.
Lina
* Heroes that can close the gap can easily chase Lina down, such as Timbersaw with 
Timber Chain and Anti-Mage with Blink.
Lina
* Timbersaw has a difficult time against magical and pure damage: Lina, Leshrac, 
Enchantress, Queen of Pain
Keeper of the Light
* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.
Lina
* 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.
Lina
* 
Viper Strike prevents buildup of Fiery Soul stacks.
* 
Corrosive Skin provides magic resistance against Lina's spells. However, Lina can counter this with Silver Edge, a common item on Lina.
* 
Poison Attack and Viper Strike can burn away Lina's small health pool.
Keeper of the Light
* The Keeper of the Light easily farms on the line against the Viper, due to the fact that it has a long-range Illuminate, and the Viper, in turn, cannot use its advantage of dominance on the center line, due to the fact that it does not reach the Keeper of the Light
Additional:
* The Keeper of the Light easily farms on the line against the Viper, due to the fact that it has a long-range Illuminate, and the Viper, in turn, cannot use its advantage of dominance on the center line, due to the fact that it does not reach the Keeper of the Light
Lina
* Heroes with a lot of burst damage, especially those who rely on casting spells: Lina, Zeus.
Keeper of the Light
* Heroes with extremely slow movement speed will cripple against Solar Bind: Medusa, Viper
Additional:
* Will-O-Wisp will keep Medusa busy after she got hit by Blinding Light.
Lina
*
Arcane Curse makes it too difficult Lina from using her abilities, preventing her from building up Fiery Soul stacks without causing harm to herself.
Last Word and 
Global Silence are great against Lina for the same reason, as well as interrupting her combos and preventing her from casting spells.
*
Keeper of the Light
* Being a cast-oriented hero, Ezalor will suffer from all of Silencer's abilities.
Global Silence is a guaranteed lengthy silence which will render Ezalor useless in a teamfight.
Arcane Curse and 
Last Word are good against any caster, since they are extremely potent.
*
*
* However, it should be worth mentioning that a smart Ezalor will buy Eul's Scepter of Divinity to dispel Silencer's abilities. Combined with the level 20 talent (Chakra Magic applies a basic dispel), Ezalor can purge Silencer's abilities off allies and himself alike.