Beastmaster
* 
Frostbite kills boars instantly on the laning stage leading to either experience lead or disabling Beastmaster from using Boar
* 
Crystal Nova nukes and slows down the attack and movement speed of Beastmaster's summons.
* 
Freezing Field grants improved self armor, nukes and slows down Beastmaster and his summons.
Keeper of the Light
* Heroes with channeling abilities: 
Enigma, 
Witch Doctor, 
Crystal Maiden.
Beastmaster
* Heroes that rely on summons will suffer against Ion Shell, which kills them very quickly: 
Beastmaster, 
Broodmother, Enigma, 
Nature's Prophet, 
Visage, 
Warlock, 
Wraith King.
Keeper of the Light
* Heroes with hastes: 
Dark Seer, 
Lycan
Beastmaster
* 
Primal Roar can be instantly dispelled by Aphotic Shield.
* The debuffs from 
Wild Axes and 
Poison from 
Call of the Wild: Boar can also be dispelled by Aphotic Shield.
Additional:
* 
Aphotic Shield effectively nullifies Primal Roar's single-target initiation on allies.
* Even being initiated by Primal Roar, 
Borrowed Time can make Abaddon extremely difficult to kill.
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.
Beastmaster
* 
Cold Embrace mitigates Primal Roar's single-target initiation on allies.
* 
Winter's Curse can turn Beastmaster's summons and Inner Beast against his teammate.
Additional:
* Beastmaster's summons and 
Inner Beast are very useful to attack his cursed teammate.
* Cold Embrace effectively mitigates Primal Roar's single-target initiation on allies.
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.
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.
Beastmaster
* Having many summons out will cause 
Echo Slam to deal extra damage.
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
Beastmaster
* 
Reactive Armor is very effective against Beastmaster's summons during laning stage and entire game.
* Timbersaw can quickly clear Beastmaster's summons with his nukes.
* 
Lotus Orb item for Timbersaw can releases roar from the target position, stunning and damaging Beastmaster and knocking away, damaging and slowing allies that stand on the way.
Beastmaster
* 
Untouchable negates Inner Beast's attack speed bonus, making her hard to kill even if stunned by Primal Roar.
* Enchantress can also take control of Beastmaster's summons.
Additional:
* 
Enchant can control Beastmaster's boars with Enchant, mitigating his effectiveness during the laning stage and teamfights.
Beastmaster
* Heroes with summoned units don't fare well against Dawnbreaker. (
Phantom Lancer ,Beastmaster ,Lycan).
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.
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.
Keeper of the Light
* Heroes with silences: 
Puck, 
Doom, 
Riki.
Beastmaster
* Heroes who summon multiple units that are not spell immune. Nature's Prophet,Lycan,Beastmaster
Keeper of the Light
* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.
Beastmaster
* Heroes with AoE abilities are a bane to Beastmaster's summons: 
Storm Spirit, 
Magnus, 
Pangolier.
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, 
Queen of Pain, Storm Spirit
Beastmaster
* Heroes who rely on high mobility are especially vulnerable to Primal Roar: Storm Spirit, 
Ember Spirit, Queen of Pain.
Beastmaster
* Heroes with Linken's Sphere as core item: 
Weaver, 
Morphling, 
Medusa.
Beastmaster
* Heroes with Linken's Sphere as core item: Weaver, Morphling, Medusa.
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.
Beastmaster
* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: 
Bane, Beastmaster, 
Bloodseeker, 
Clockwerk, Doom, 
Shadow Shaman.
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.
Beastmaster
* Heroes with strong dispels can remove Primal Roar's stun: 
Abaddon, 
Slark, 
Oracle.
Keeper of the Light
* Heroes with dispels: 
Legion Commander, Oracle, Slark, Phantom Lancer
Keeper of the Light
* Melee carries during the laning phase: 
Sven, Slark
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...
Keeper of the Light
* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer
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.
Beastmaster
* Heroes with disables that go through spell immunity can end Bloodseeker before he has the chance to do anything: 
Batrider, Beastmaster
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.
Beastmaster
* Heroes with illusions and summons can manfight Night Stalker: 
Terrorblade, Beastmaster, Broodmother.
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
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.
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
Beastmaster
* The Hawk can easily find Monkey King while he is sitting on a tree.
* Wild Axes can knock out Monkey King from tree.
* Boars drastically reduce Monkey King's attack speed, making it harder for him to gain 
Jingu Mastery stacks.
Additional:
* Wild Axes can chop down trees, making it difficult for Monkey King to utilize Tree Dance well.
* 
Call of the Wild Hawk can scout Monkey King when he is perched on top of trees.
* Primal Roar can stun Monkey King for a lengthy duration even with spell immunity.
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.
Beastmaster
* Primal Roar takes Sven out of the fight completely, even with 
Black King Bar.
Keeper of the Light
* Melee carries during the laning phase: Sven, Slark
Beastmaster
* Wild Axes, Primal Roar and 
Drums of Slom can deal high damage to Chen and clear waves of his creeps.
* Even though Chen can take control of the Boar from 
Call of the Wild Boar at any time with 
Holy Persuasion, which could put Beastmaster in a disadvantage against Chen. Skilled Beastmaster can buy 
Helm of the Overlord to regain control of it to counter this problem.
* Smart Beastmaster can also buy Bloodthorn to prevent Chen from taking control of the Boar from Call of the Wild Boar and make Chen more vulnerable to Beastmaster.
Keeper of the Light
* Heroes with summons/illusions/neutral creep armies: Beastmaster, 
Chen, Naga Siren
Beastmaster
* Wraith King's lack of area of effect spells makes him easily overwhelmed by Beastmaster's summons.
Keeper of the Light
* Heroes which rely exclusively on right clicks will struggle somewhat against Blinding Light: Phantom Assassin, Wraith King, Medusa
Beastmaster
* Illusion or summon-based heroes can be a problem to Viper due to his lack of AoE damage: Naga Siren, Phantom Lancer, Beastmaster
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
Beastmaster
* Wild Axes destroys large amounts of trees specially upgraded with Aghanim's Scepter,
Beastmaster
* Primal Roar and the slow from Boars make kiting Troll Warlord very easy.
Beastmaster
* Beastmaster's Hawk can find Tinker easily while he is pushing or blinking into trees.
Keeper of the Light
* Heroes with hastes: Dark Seer, Lycan
Beastmaster
* Primal Roar allows Beastmaster to keep Lycan in place after he used his Shapeshift.
Keeper of the Light
* Keeper of the Light has a blind, which causes Lycan to miss his attacks.
Beastmaster
* Primal Roar and the slow from Boars makes kiting Ursa very easy.
Beastmaster
* Inner Beast helps Beastmaster's team destroy 
Supernova quickly.
Keeper of the Light
* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.
Beastmaster
* Long ranged disables, especially those that pierce spell immunity, cancel Black Hole: Beastmaster's Primal Roar, Bane's 
Fiend's Grip, 
Faceless Void's 
Chronosphere, Magnus's 
Reverse Polarity, 
Axe's 
Berserker's Call, 
Pudge's
Meat Hook.
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.
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.
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.
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
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
Beastmaster
* Any long duration disables that can pierce through both, Pierce The Veil and Black King Bar are devastating against Muerta: Enigma's Black Hole, 
Dawnbreaker's 
Solar Guardian, Axe's Berserker's Call, Naga Siren's Aghanim's Scepter upgraded 
Ensnare and 
Reel In from Aghanim's Scepter, 
Jakiro's Aghanim's Scepter upgraded 
Macropyre, Bane's Fiend's Grip, Pudge's 
Dismember, Batrider's 
Flaming Lasso, Beastmaster's Primal Roar, 
Grimstroke's 
Soulbind, Medusa's 
Stone Gaze, Magnus's Reverse Polarity.
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
Beastmaster
* Heroes with AoE abilities are a bane to Beastmaster's summons: Storm Spirit, Magnus, Pangolier.
Beastmaster
* Heroes with other kind of disables that pierce spell immunity can hold Pangolier in place during Rolling Thunder: Axe, Beastmaster, Enigma, Magnus, Pudge, Batrider, Bane, Winter Wyvern
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
Beastmaster
* Heroes who rely on high mobility are especially vulnerable to Primal Roar: Storm Spirit, Ember Spirit, Queen of Pain.
Beastmaster
* Skywrath Mage also has a terrible time fighting against anything that isn't a hero. His skills are mostly target-based and he has terrible strength and agility, he can easily be kited or harassed by illusion-based heroes like 
Chaos Knight and Phantom Lancer, or by Heroes that summon other units like 
Lone Druid, Lycan and Beastmaster.
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
Beastmaster
* Heroes with disables that ignore spell immunity will render Phantom Assassin completely useless in teamfights throughout the game: Axe, Enigma, Vengeful Spirit, Doom, Bane, Beastmaster, Pudge, Medusa, Warlock.
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 punish mobile heroes: Bloodseeker, Keeper of the Light, 
Kunkka, 
Disruptor.
Beastmaster
* Long lockdown is a great way to deal with Axe to prevent Berserker's Call from being used, heroes such as Legion Commander, Beastmaster and 
Primal Beast are good examples of this.
Beastmaster
* Heroes who relies on illusions and summons (Beastmaster, Chaos Knight, etc.).
Beastmaster
* Heroes with summons or illusions can counter Flux, such as Beastmaster , Chen, or Shadow Demon.
Beastmaster
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Keeper of the Light
* Heroes that can jump and kill him: 
Meepo, 
Clinkz, Templar Assassin
Beastmaster
* Attacks from Boars and the attack speed boost from Inner Beast will quickly wear down 
Refraction.
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.
Beastmaster
* Primal Roar and the slow from Boars make kiting Tiny very easy.
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
Beastmaster
* Heroes who rely on high mobility are especially vulnerable to Primal Roar: Storm Spirit, Ember Spirit, Queen of Pain.
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.
Beastmaster
* Heroes with AoE abilities are a bane to Beastmaster's summons: Storm Spirit, Magnus, Pangolier.
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.
Beastmaster
* Heroes with Linken's Sphere as core item: Weaver, Morphling, Medusa.
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.
Keeper of the Light
* Heroes that can jump and kill him: Meepo, Clinkz, Templar Assassin
Beastmaster
* Because only one clone needs to be killed in order to kill Meepo, heroes that excel at singling out enemies can also be a detriment to him, such as Batrider, Beastmaster, Pudge and Clockwerk.
Beastmaster
*
False Promise effectively nullifies Primal Roar's single-target initiation on allies.
Purifying Flames kills Beastmaster's Hawk instantly and Boar with two casts.
*
Keeper of the Light
* Heroes with dispels:
Legion Commander, 
Oracle, 
Slark, 
Phantom Lancer