Lycan
* 
Pugna's 
Decrepify prevents the target from taking physical damage or doing damage, which poses a huge problem for Lycan, as he mainly deals physical 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
Lycan
* Paralyzing cask bounces between him and his wolves, keeping him stunned for long amounts of time.
Keeper of the Light
* Heroes with channeling abilities: 
Enigma, 
Witch Doctor, 
Crystal Maiden.
Lycan
* Jakiro's area-of-effect abilities make him strong against heroes who rely on illusions and summons: 
Terrorblade, 
Naga Siren 
Chaos Knight, 
Phantom Lancer, 
Broodmother, 
Nature's Prophet, 
Lycan, 
Wraith King, 
Visage.
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.
Lycan
* All of Timbersaw's spells deal AoE damage, killing Lycan's summons very quickly.
* 
Reactive Armor will gain stacks quickly because of Lycan's summons.
Lycan
* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, 
Arc Warden, 
Warlock, 
Chen
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
Lycan
* 
Kraken Shell grants him massive physical attack protection
* 
Anchor Smash will wipe the area, clearing Lycan's wolves.
Lycan
* Tidebringer's cleave will cripple any of his summons.
* Could potentially build Heaven's Halberd to cripple Lycan even more.
Additional:
* 
Tidebringer can be used to kill Lycan's summons.
* Can also build into 
Heaven's Halberd which will disable Lycan's auto attacks, crippling him even more.
Lycan
* 
Stroke of Fate deals more damage when it hits more targets which makes it very effective in dealing with Lycan and his units.
* 
Soulbind prevents Lycan from running away and makes him very easy to deal with.
Lycan
* Brewmaster can waste a large portion of Lycan's ultimate by putting him in Cyclone.
* Lycan has no way to stop Brewmaster from using Primal Split by himself.
* Lycan's team often tries to push towers as a group, and Brewmaster excels at winning teamfights while trying to defend a tower.
Lycan
* 
Quill Spray can be used to kill Lycan's summons.
* 
Bristleback allows him to stay alive against Lycan while dishing out counter attacks
* He can overpower Lycan with his 
Warpath instead.
Additional:
* Lycan's wolves deal little damage to Bristleback, and are easily killed by Quill Spray, even when they're invisible.
* Lycan's lack of burst damage makes it very hard for him to kill Bristleback, especially when his back is turned.
Lycan
* 
Arctic Burn allows Winter Wyvern to escape Lycan, even when he uses his ultimate.
* 
Splinter Blast is very effective in dealing with Lycan's summons.
* 
Cold Embrace saves allies from Lycan's raw physical damage and can buy allies enough time to turn the tide of battle.
* 
Winter's Curse stops Lycan in his tracks and is very effective because of his summons.
Additional:
* All of Lycan's damage is physical which is totally negated by Cold Embrace.
* Lycan often moves around with large amount of creeps, wolves created by 
Summon Wolves and neutral creep dominated by 
Helm of the Dominator which can be easily cleared by Splinter Blast or used as a great source of damage by Winter's Curse. If you catch Lycan with creeps nearby and affected by 
Shapeshift using Winter's Curse on him will most certainly end up with his death.
Lycan
* A well landed 
Fissure can potentially take Lycan out of the fight for several seconds, who heavily relies on precious seconds from Black king bar and Shapeshift to fight.
* 
Aftershock reduces the effectiveness of his summons and can prove quite irritating for Lycan.
* 
Echo Slam is very powerful with the sheer amount of Lycan's units and will cause him to think twice when pushing towers.
Lycan
* Can cast 
Demonic Conversion on one of Lycan's Wolves, making this a numbers fight.
* 
Malefice will greatly reduce his ability to engage
* 
Midnight Pulse can steep an area making it harder for Lycan to engage in.
Keeper of the Light
* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.
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
* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.
Lycan
* Lycan cannot escape from a Pounce even if he uses Shapeshift, and has no disabling abilities to stop Slark.
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 teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, 
Puck, 
Queen of Pain, 
Storm Spirit
Lycan
* Heroes that can summon units will have their summons destroyed very quickly if badly micro-managed, like Chen, Lycan, and Phantom Lancer.
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.
Keeper of the Light
* Heroes with hastes: 
Dark Seer, Lycan
Lycan
* Heroes with summoned units don't fare well against Dawnbreaker. (Phantom Lancer ,
Beastmaster ,Lycan).
Keeper of the Light
* Heroes with silences: Puck, Doom, Riki.
Lycan
* 
Dragon Knight's insanely high armor and splash damage can cause Lycan to struggle taking him down.
Lycan
* 
Treant Protector grants protection against his attacks with 
Living Armor and his ultimate, 
Overgrowth is a massive AoE disarm and root that pierces spell immunity, causing trouble to Lycan. You will find yourself in need of an ally's dispel or forced to pop 
Black King Bar for its dispel.
Additional:
* Lycan has no kind of teleport, being only able to walk, and heavily relies on his attacks. As Overgrowth roots and disarms the targets, Lycan can't do much in an overgrowth field.
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.
Lycan
* 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.
Lycan
* Heroes who summon multiple units that are not spell immune. Nature's Prophet,Lycan,Beastmaster
Lycan
* 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
* 
Finger of Death can instantly shred many targets, especially fragile Heroes like Keeper of the Light, Ancient Apparition or 
Bounty Hunter.
Lycan
* Melee heroes who rely on summons, illusions, or clones will trigger Counter Helix more often, thus taking more damage: 
Meepo, Lycan, Phantom Lancer
Additional:
* 
Berserker's Call can keep Lycan in place during his Shapeshift even through Black King Bar.
* 
Counter Helix is very effective against Lycan because of his summons.
* 
Culling Blade will prevent Lycan from running away with Shapeshift when he drops low.
Keeper of the Light
* Heroes that can jump and kill him: Meepo, 
Clinkz, 
Templar Assassin
Lycan
* Heroes who rely strongly on melee physical damage will fare badly against Omniknight's Guardian Angel: Phantom Assassin, 
Juggernaut, Dragon Knight, Lycan, 
Ursa, Troll Warlord
Additional:
* 
Guardian Angel completely negates all of Lycan's damage since Lycan mainly deals physical damage.
* 
Purification can also be a problem for Lycan, as Purification deals damage around the target, which poses a problem for him and his summons.
Keeper of the Light
* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer
Keeper of the Light
* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
Lycan
* 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.
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
* 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
Lycan
* Her 
Mana Shield is too tough for Lycan to break.
* 
Mystic Snake can hit for a massive damage once it spread between his summons.
Additional:
* Can be easily petrified despite his speed.
* Summoned wolves will be targeted by Split Shot or Mystic Snake
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.
Lycan
* 
Great Cleave will kill Lycan's summons very rapidly.
* 
Warcry will allow Sven and his allies to tank Lycan's damage, which is mainly physical.
* 
Storm Hammer will damage and stun Lycan's as well as his summons.
Keeper of the Light
* Keeper of the Light's AoE blind can keep Sven from landing hits.
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.
Lycan
* Phantom Assassin's 
Blur is a real problem for Lycan, as he relies entirely on direct attacks to deal damage.
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
Lycan
* 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.
Keeper of the Light
* Heroes which rely exclusively on right clicks will struggle somewhat against Blinding Light: Phantom Assassin, Wraith King, Medusa
Lycan
* Lycan relies heavily on right clicks making Untouchable very effective against him.
* If he tries to run away Impetus will do huge amounts of damage.
Additional:
* She can 
Enchant one of the wolves to her side.
* Lycan will struggle greatly to harm Enchantress through her 
Untouchable which can seriously slow down Lycan's attack speed even if Lycan is spell immune.
Lycan
* Heroes with haste can negate Enchant's slow: 
Weaver, Dark Seer, Lycan, 
Centaur Warrunner.
Lycan
* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, Pugna, Nature's Prophet, Dark Seer, Lycan, 
Tusk
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
Lycan
* Lycan can clear waves of Chen's creeps with his wolves from Summon Wolves, especially once Lycan takes +2 Wolves summoned talent. And even though Chen can convert one of his wolves with 
Holy Persuasion, Lycan can counter this by buying 
Helm of the Overlord to regain control of it. Uncontrollable wolves summoned from 
Aghanim's Shard upgrade Summon Wolves cannot be converted with Holy Persuasion.
* Shapeshift allows him to chase down Chen and kill him easily.
* 
Howl can reduce attack damage of both, Chen and his creeps.
Keeper of the Light
* Heroes with summons/illusions/neutral creep armies: Beastmaster, Chen, Naga Siren
Lycan
* Heroes with single-target abilities will be overwhelmed by Lycan and his summons: Wraith King, 
Bane, Phantom Assassin.
Keeper of the Light
* Heroes which rely exclusively on right clicks will struggle somewhat against Blinding Light: Phantom Assassin, Wraith King, Medusa
Lycan
* Heroes who can summon illusions and summons because Terrorblade has no abilities to deal with multiple enemies at once outside Reflection: Shadow Shaman, Naga Siren, Broodmother, Lycan, Enigma, Chaos Knight, Phantom Lancer, 
Shadow Demon, Dark Seer, Nature's Prophet, 
Invoker, 
Morphling, Visage, 
Grimstroke with Aghanim's Scepter.
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
Lycan
* Shapeshift allows Lycan to escape from Upheaval with maximum movement speed.
* Warlock doesn't have a good solution to deal with Lycan's wolves from Summon Wolves.
Lycan
* Lycan's ultimate makes him immune to slows from Ursa's 
Earthshock as well as allowing him to outmaneuver Ursa during 
Enrage. Lycan can also easily chase down Ursa while shapeshifted, should Ursa try to flee.
Lycan
* Shapeshift allows Lycan to get close and disable Marksmanship.
* Shapeshift also makes him immune to slows like Drow Ranger's Frost Arrows.
Additional:
* The Wolves's speed causes the knockback from 
Gust to be ineffective.
* Drow Ranger lacks escapes and loses her 
Marksmanship when someone is near her. Lycan can take advantage of these weaknesses of Drow Ranger.
Lycan
* Shapeshift allows Lycan to chase down Earth Spirit.
Lycan
* Lycan doesn't care much about Lich's slows thanks to Shapeshift.
* Chain Frost can bounce to the wolves that Lycan summons.
Additional:
* 
Lich possesses a lot of slows, which Lycan doesn't care about when he Shapeshifts.
* Lich has no in-built escape, which makes him a good target for Lycan.
Lycan
* Howl reduces a good chunk of Marci's attack damage that she relies heavily on, and the armor reduction works better on her because of her low armor.
* Shapeshift renders Lycan immune to slow from Rebound and Unleash.
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.
Lycan
* 
Magnetic Field is useless against melee heroes, so Lycan can attack Arc Warden without missing.
* 
Flux doesn't affect Lycan that much, because Shapeshift grants immunity to slows and because he is never alone.
* If their 
Tempest Double has been called, Lycan can still kill Arc Warden before the double expires.
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.
Lycan
* Shapeshift increases Lycan's movement speed and renders him unslowable, allowing him to easily avoid and escape Ancient Apparition's abilities.
* Lycan has fast summons, both his wolves from Summon Wolves can do heavy damage to Ancient Apparition due to his immobility and low armor.
Lycan
* Mirana's Leap is ineffective if Lycan uses Shapeshift. It also allows him to dodge Sacred Arrow.
Lycan
* He can send wolves to defuse 
Proximity Mines, and he can catch up Techies and kill him before they can deny themselves. Even if the suicide is successful, Lycan can still survive because of his tankiness.
Lycan
* The movement speed granted from Shapeshift means that Spectre has no way to punish Lycan if he wants to splitpush or pick off supports. Furthermore, he will kite 
Haunt and cannot be slowed by 
Spectral Dagger.
* Lycan is often part of an early game push strategy which is often the best counter to Spectre because she needs a lot of time and space to come online as a late game carry.
Lycan
* Windranger tends to fare badly against high mobility heroes that can easily dodge Powershot, close the gap on her when she uses Windrun or escape from Focus Fire's reach. Examples of such heroes include 
Spirit Breaker, Lycan, Storm Spirit, 
Earth Spirit, 
Void Spirit, Slark and others.
Lycan
* You can easily kill a squishy 
Sniper, due to your high movement speed and his lack of escape.
Lycan
* Once you get a Black King Bar, squishy spellcasters like 
Zeus, 
Skywrath Mage and others will be probably easy to deal with.
Lycan
* Lycan and Weaver has abilities that allow them to move at maximum movement speed, and those abilities can't be dispelled, potentially wasting the slow from Demonic Purge.
Keeper of the Light
* Heroes that have AoE damage: 
Lina, Keeper of the Light, 
Timbersaw, 
Leshrac, 
Bristleback, 
Axe.
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.
Lycan
* Heroes with low armor and little mobility, like Huskar, 
Io, etc. will also have an unfortunate fate.
Lycan
* Heroes with single-target abilities will be overwhelmed by Lycan and his summons: Wraith King, Bane, Phantom Assassin.
Lycan
* Zeus can deal a huge amount of damage, but he lacks defensive abilities, such as good mobility or resistance. Due to that, he doesn't like to be touched by any means. Heroes with higher damage output and good mobility will often get easily near Zeus and trade damage (eventually causing Zeus's downfall). Such Heroes include: Lycan, Slark, Storm Spirit, Spectre and others.
Keeper of the Light
* Large area-of-effect with delay or require channeling: Enigma, Crystal Maiden, Invoker, 
Shadow Fiend, Pugna, Keeper of the Light, Dawnbreaker.
Additional:
* 
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.
Lycan
* Lycan's high health allows him to easily shrug off Nyx Assassin's burst damage and fend him off.
* As Lycan commonly buys Black King Bar, he can use it to freely attack Nyx Assassin and chase after him with Shapeshift.
* Lycan can also use his wolves from Summon Wolves to attack Nyx Assassin while he has Spiked Carapace active without getting stunned himself.
Lycan
* Any Hero with high mobility will be neutralized by dream coil: Queen of Pain, Storm Spirit, 
Ember Spirit, Lycan, 
Bloodseeker, Anti-Mage, Timbersaw.
Keeper of the Light
* Low health spellcasters: Lina, Witch Doctor, Tinker, Keeper of the Light, all rely heavily on their spells and are fragile heroes. They all also have avoidable spells, allowing Puck to get to them and quickly burst them down.
Lycan
* A Lycan with Shapeshift can always run down Puck for a very quick kill due to its low armor. It is important to abuse as many cliffs and trees as possible to escape from a Lycan.
Keeper of the Light
* Heroes who are strong against mobile heroes: 
Disruptor, Bloodseeker, Kunkka, Keeper of the Light.
Lycan
* Vision from Charge of Darkness will easier to catch Lycan Shapeshift and Charge of Darkness out of reach Lycan Summon Wolves and Lycan's other creeps. Until upgrade Aghanim's Scepter faster catching Lycan Shapeshift.
Additional:
* 
Charge of Darkness allows Spirit Breaker to catch up to Lycan after he uses Shapeshift.
Lycan
* 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, Wraith King.
Keeper of the Light
* Heroes that punish mobile heroes: Bloodseeker, Keeper of the Light, Kunkka, Disruptor.
Lycan
* 
Primal Roar allows Beastmaster to keep Lycan in place after he used his Shapeshift.
Keeper of the Light
* Illuminate clears Beastmaster's summons and is effective against his push.
Keeper of the Light
* 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 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.
Lycan
* Heroes with summons: Lycan, Broodmother, Visage, Nature's Prophet, Warlock.
Lycan
* Faceless Void can lock Lycan down with his 
Chronosphere pinning him down as long as his ultimate is up.
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
* Vulnerable spellcasters with no escape mechanisms are easy targets for Huskar: Lich, Crystal Maiden, 
Silencer, Keeper of the Light, Venomancer, etc.
Lycan
* Heroes with low armor and little mobility, like Huskar, Io, etc. will also have an unfortunate fate.
Keeper of the Light
* 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.
Additional:
* 
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.
Lycan
* Void's slow is useless against Lycan by activating Shapeshift.
* Night Stalker's single target abilities (with the exception of Void upgraded by Aghanim's Scepter) is not very effective against Lycan's Summon Wolves during the early and mid game.
Lycan
* Heroes who rely on physical damage output to be effective will fare badly against Muerta's 
Pierce the Veil: Phantom Assassin, Terrorblade, 
Drow Ranger, 
Lifestealer, Anti-Mage, Alchemist, Lycan, Clinkz, Sniper.
Lycan
* Heroes with abilities that can close the gap can easily kill Muerta: Storm Spirit, Earth Spirit, Ember Spirit, Void Spirit, Lycan, Chaos Knight, Tusk.
Keeper of the Light
* Heroes that can jump and kill him: Meepo, Clinkz, Templar Assassin
Lycan
* Multiple attackers thanks to summoned units or clones: Meepo, Witch Doctor, Lycan, Enigma, Shadow Shaman
* 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
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.
Lycan
* Shapeshift is useful for killing or escaping Silencer.
* Summon Wolves, can be used to hunt and harass silencer - even when Lycan himself can't fight.
Lycan
* Heroes who have summons, which can be quickly cleared by his powerful area of effect skill: Nature's Prophet, Enigma, Lycan
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
Lycan
* Rupture completely negates Lycan's high mobility.
Rupture completely negates Lycan's high mobility.
Bloodrage.
* All of Lycan's summons are good sources of healing with Bloodrage.
Additional:
*
* All of Lycan's summons are good sources of healing with
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.
Rupture.
* 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