Omniknight
* 
Fortune's End's AoE dispel will remove Heavenly Grace and Guardian Angel.
Additional:
* Oracle can dispel 
Heavenly Grace (which he can also bait out with Fate's Edict).
* With Fortune's End, Oracle can dispel 
Guardian Angel in an area of effect.
Keeper of the Light
* Heroes with dispels: 
Legion Commander, 
Oracle, 
Slark, 
Phantom Lancer
Omniknight
* Heroes that have a weak laning stage: 
Spectre, 
Nyx Assassin, 
Clockwerk, 
Spirit Breaker, 
Omniknight, 
Pudge.
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.
Omniknight
* Heroes who can drain mana can make Omniknight useless after he uses one or two abilities: 
Lion, 
Anti-Mage, Nyx Assassin.
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.
Omniknight
* Jakiro's area-of-effect abilities that deal magical damsge make it hard for Omniknight to save multiple enemy heroes at once with 
Purification and 
Repel, and Guardian Angel and to harass Omniknight on lane.
* Aghanim's Scepter upgraded 
Macropyre allows Jakiro to deal pure damage and slow enemy heroes which can pierce debuff immunity, rendering both Repel and Guardian Angel useless.
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.
Omniknight
* 
Doom applies a basic dispel upon cast, so it can remove Guardian Angel.
* Casting Doom on Omniknight will also prevent him from healing allies with Purification, or casting buffs like Repel and Guardian Angel, basically turning him into a harmless creep.
Additional:
* Doom turns Omniknight into a walking creep, or completely takes out his buffed cores, also removing Heavenly Grace and Guardian Angel in the process.
* With 
Devour used on Satyr Banisher, Doom will have access to Satyr Banisher's 
Purge, which will allow him to remove Heavenly Grace and Guardian Angel.
Keeper of the Light
* Heroes with silences: 
Puck, 
Doom, Riki.
Omniknight
* Heroes who can harass Omniknight out of lane will keep him weak in the mid game: 
Viper, 
Venomancer, 
Clinkz.
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.
Omniknight
* Heroes who cannot escape from Trample early might be easy first blood. Heroes like 
Witch Doctor and Omniknight should play very cautiously alone...
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...
Omniknight
* Heroes who can drain mana can make Omniknight useless after he uses one or two abilities: Lion, Anti-Mage, Nyx Assassin.
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
* 
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.
Omniknight
* 
Arcane Orb's pure damage penetrates Guardian Angel's defense.
* 
Astral Imprisonment's mana steal is devastating to Omniknight's already low mana pool.
Omniknight
* 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.
Omniknight
* 
Dispel Magic from {U:Storm} instantly removes Heavenly Grace and Guardian Angel from Omniknight's allies in its radius of effect.
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
Omniknight
* Guardian Angel does not offer protection from 
Eclipse, though it will negate damage from 
Moon Glaives.
* Luna's high magical damage from 
Lucent Beam and Eclipse can often finish allied heroes before Omniknight can save them with Purification.
* Likewise, Luna's high physical damage from Moon Glaives and 
Lunar Blessing is strong enough to counter debuff immunity from Repel.
Additional:
* Guardian Angel does not offer protection from Eclipse, though it will negate damage from Moon Glaives.
* Luna's high magical damage from Lucent Beam and Eclipse can often finish allied heroes before Omniknight can save them with Purification.
Omniknight
* All of Omniknight's abilities are valuable for Rubick to 
Spell Steal, and Omniknight has no throwaway ability to cover his last used spell.
Omniknight
* Heroes who can drain mana can make Omniknight useless after he uses one or two abilities: Lion, Anti-Mage, Nyx Assassin.
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
Omniknight
* Impetus is not blocked by Guardian Angel. A {U:Satyr Banisher} can also be controlled to dispel Guardian Angel.
Additional:
* Enchantress's 
Impetus deals pure damage instead of physical damage and ignores Guardian Angel, thus fully negating one of Omniknight's most important abilities for teamfights.
* Similar to Doom, Enchantress can use 
Enchant on Satyr Banisher, which will give her access to Satyr Banisher's Purge, and allow her to remove Heavenly Grace and Guardian Angel.
Omniknight
* 
Mortimer Kisses can reduce Omniknight's impact in teamfights. Omniknight's Heavenly Grace cannot purge multiple stacks of Mortimer Kisses. The damage is also magical, making Omniknight's ultimate, Guardian Angel, useless.
Omniknight
* Heroes with long cooldowns on their abilities or ultimate will struggle against the relentless pressure provided by 
Fiend's Gate: Terrorblade, 
Dragon Knight, Omniknight.
Keeper of the Light
* Heroes with hastes: 
Dark Seer, 
Lycan
Omniknight
* Heroes with large magical AoE damage will fare well against Omniknight: 
Lich, Ancient Apparition, 
Jakiro, 
Disruptor.
Omniknight
* Heroes under Guardian Angel can be still damaged from the pure damage of 
Black Hole and magical damage of 
Midnight Pulse.
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 that can jump and kill him: 
Meepo, Clinkz, Templar Assassin
Omniknight
* Heroes that can purge buffs can dispel Guardian Angel: 
Invoker, 
Shadow Demon, Oracle.
Additional:
* Demonic Purge can dispel Guardian Angel on the key target during combat, allow your allies to finish them.
Omniknight
* Heroes that rely on slows or low-duration stuns have trouble catching Weaver: Omniknight, Lich.
Omniknight
* Heroes with large magical AoE damage will fare well against Omniknight: Lich, Ancient Apparition, Jakiro, Disruptor.
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, 
Queen of Pain, 
Storm Spirit
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
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
* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.
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.
Omniknight
* Heroes with naturally low mana can be easily shut down by E.M.P.: 
Sven, 
Tiny, 
Wraith King, Omniknight
Additional:
* 
Tornado dispels Heavenly Grace and Guardian Angel from multiple targets.
* Guardian Angel is generally useless against Invoker as he primarily relies on magical damage.
* 
E.M.P. depletes Omniknight's already small mana pool.
* Invoker's many disables keep Omniknight's team occupied until Guardian Angel times out.
Keeper of the Light
* Heroes that can jump and kill him: Meepo, Clinkz, Templar Assassin
Omniknight
* Heroes who can harass Omniknight out of lane will keep him weak in the mid game: Viper, Venomancer, Clinkz.
Omniknight
* Heroes with large physical resistance do not counter Muerta's 
Pierce the Veil such as Omniknight or 
Tidehunter.
Keeper of the Light
* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer
Omniknight
* 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 can also buy items that deal magical damage like 
Radiance, 
Dagon, 
Ethereal Blade, 
Revenant's Brooch, 
Veil of Discord and 
Gleipnir to attack Omniknight's allies protected with Guardian Angel.
Additional:
* 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.
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
Omniknight
* Guardian Angel can negate all the physical damage output during Chronosphere.
* When Faceless Void Time Walk's on top of an enemy it becomes a perfect target for Purification
Additional:
* Guardian Angel can negate all the physical damage output from Faceless Void during 
Chronosphere.
* If Faceless Void 
Time Walks on top of an ally Purification + Heavenly Grace can turn the fight around.
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.
Omniknight
* In the early game, Omniknight can look like an easy target for Spirit Breaker, but with Purification and 
Hammer of Purity, what could be an opportunity could quickly turn into disaster.
* Repel can be used to counter Charge of Darkness by minimizing the damage and lowering the stun duration with status resistance.
* Spirit Breaker's Greater Bash from all sources (Charge of Darkness or normal attacks) will deal no damage at all if Omniknight and his allies are protected with presence.
* Due to this, Spirit Breaker's damage will always be lower when targeting Omniknight.
Keeper of the Light
* Heroes that punish mobile heroes: 
Bloodseeker, Keeper of the Light, 
Kunkka, Disruptor.
Omniknight
* 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.
Keeper of the Light
* Illuminate clears Beastmaster's summons and is effective against his push.
Omniknight
* Guardian Angel negates most of Gyrocopter's physical АоЕ damage.
* Heavenly Grace dispels Homing Missile stun.
Omniknight
* Being mostly a physical damage dealer, Sniper's effectiveness is greatly reduced by Omniknight's Guardian Angel.
* Omniknight's 
Degen Aura allows him to slow sniper and catch him. Sniper has to then use some escape item.
* Omniknight can also protect an ally from being finished off by Assassinate by using Purification and Repel which grants a massive strength boost.
Omniknight
* Global Guardian Angel will protect his allies from Spectre's 
Haunt, both when they are alone and in teamfights.
* Purification is a major problem for melee enemies, Spectre included, since they must be next to an enemy in order to attack. The AoE damage also allows Spectre to be singled out from her illusions.
* Degen Aura will prevent Spectre from chasing Omniknight, further exacerbated by her terrible mobility outside Haunt.
Omniknight
* Purification heals a teammate targeted by Reality Rift and heavily damages Chaos Knight and his illusions in the process.
* Guardian Angel blocks all of Chaos Knight's damage for a long duration.
Additional:
* 
Phantasms can be easily killed with Purification.
* Heavenly Grace dispels the stun from 
Chaos Bolt and the armor reduction from 
Reality Rift.
* Guardian Angel works well against Chaos Knight's overwhelming reliance on physical burst damage.
Keeper of the Light
* Heroes with hastes: Dark Seer, Lycan
Omniknight
* 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
* Keeper of the Light has a blind, which causes Lycan to miss his attacks.
Keeper of the Light
* Heroes with dispels: Legion Commander, Oracle, Slark, Phantom Lancer
Omniknight
* Slark's dependence on Pounce and close range makes him very easy to hit with Purification and Hammer of Purity.
* Slark's damage, even with a high count of Essence Shift stacks, is easily negated by Omniknight's heals and Guardian Angel.
Keeper of the Light
* Melee carries during the laning phase: Sven, Slark
Omniknight
* Repel can be used to dispel 
Gust on the allies affected by it.
* In team fights, Guardian Angel renders Drow Ranger's physical damage useless, and Drow Ranger has no way to purge it. And to make thing worse, Drow Ranger is not a common 
Nullifier wielder to counter this problem at all.
Omniknight
* Guardian Angel nullifies the physical damage from Exorcism during teamfights. And when upgraded with Aghanim's Scepter, it also prevents Death Prophet from pushing towers. However, Death Prophet can partially counter this issue with Eul's Scepter of Divinity, a common item on Death Prophet.
* Heavenly Grace dispels 
Silence.
Additional:
* 
Exorcism's damage is blocked by Guardian Angel.
* Heavenly Grace can dispel Silence allies if Omniknight is able to cast it.
Keeper of the Light
* Heroes with teleports to escape Solar Blind and Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
Omniknight
* Purification and Hammer of Purity can easily catch Phantom Assassin once she jumps with 
Phantom Strike in to attack.
* Heavenly Grace can be used to dispel slow from 
Stifling Dagger, and disables from the items Phantom Assassin relies on.
* Phantom Assassin depends entirely on physical attacks and her damage output is 100% physical. Therefore, since she has no any sources of magical damage output and hates going for items that deal magical damage like Dagon, Ethereal Blade and Revenant's Brooch, Guardian Angel will render her completely useless.
* Purification, Heavenly Grace and Guardian Angel can be used to save an allied hero before Phantom Assassin can finish them off with 
Coup De Grace.
Additional:
* Purification and Hammer of Purity can easily catch Phantom Assassin once she jumps with Phantom Strike in to attack.
* Heavenly Grace can be used to dispel slow from Stifling Dagger, and disables from the items Phantom Assassin relies on.
* Phantom Assassin depends entirely on physical attacks and her damage output is 100% physical. Therefore, since she has no any sources of magical damage output and hates going for items that deal magical damage like Dagon, Ethereal Blade and Revenant's Brooch, Guardian Angel will render her completely useless.
* Purification, Heavenly Grace and Guardian Angel can be used to save an allied hero before Phantom Assassin can finish them off with Coup De Grace.
Keeper of the Light
* Heroes which rely exclusively on right clicks will struggle somewhat against Blinding Light: Phantom Assassin, Wraith King, Medusa
Omniknight
* Heavenly Grace reduces Fireblast stun time and dispels Ignite.
* Purification can heal damaged heroes if needed.
Omniknight
* Guardian Angel makes allies immune to all physical damage, effectively causing Tidebringer to do no damage.
* Purification is a powerful, pure damaging heal that can save Omniknight's allies after Kunkka's large damage.
Omniknight
* Purification does great damage to Clockwerk when fighting an enemy inside Power Cogs.
* Due to Clockwerk's very low damage output, Omniknight will have more than enough time to Purification and Heavenly Grace any enemy hero Clockwerk initiates on.
* For the same reasons, Omniknight also makes a powerful ally for Clockwerk when the situation is reversed.
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.
Omniknight
* The pure damage provided by Purification is a great addition for killing Ember Spirit, as well as a good way of saving teammates.
* Guardian Angel will temporarily save his allies from Sleight of Fist's physical damage, and Ember Spirit is not a hero that will get 
Orchid Malevolence to counter it.
Omniknight
* Guardian Angel completely counters 
Winter's Curse if Omniknight is able to cast it.
Additional:
* Guardian Angel completely counters Winter's Curse, allowing his team to survive Winter Wyvern's initiation.
* Purification and Repel are very useful against Arctic Burn, Splinter Blast and Winter's Curse as well.
Omniknight
* Omniknight's healing prevents allies from dropping low enough for 
Culling Blade
* Heavenly Grace dispels 
Battle Hunger.
* Axe also tends to get close to allied heroes in order to damage them with his 
Counter Helix, which can easily be punished by Purification.
Keeper of the Light
* Heroes with summons/illusions/neutral creep armies: 
Beastmaster, 
Chen, Naga Siren
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
* 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
Omniknight
* Heroes that can save their allies can be a big problem for Mars: Dazzle, Omniknight.
Omniknight
* 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
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
* Heroes with silences: Puck, Doom, Riki.
Omniknight
* Heroes with spell immunity or pseudo-blinks which provide invulnerability: 
Lifestealer, Juggernaut, Omniknight, Huskar, and 
Tusk have spells which allow them to easily escape Dream Coil.
Keeper of the Light
* Heroes who are strong against mobile heroes: Disruptor, Bloodseeker, Kunkka, Keeper of the Light.
Omniknight
* Heroes who possess abilities that can save targets from being killed by Reaper's Scythe: Abaddon, 
Bane, Outworld Destroyer, Shadow Demon, Omniknight, etc.
Omniknight
* 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
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.
Omniknight
* Guardian Angel completely negates all physical damage, including 
Omnislash.
Additional:
* Omnislash (and 
Swiftslash) is blocked by Guardian Angel.
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.
Omniknight
* Heroes with strong dispels can dispel Bane's disables from their allies: Oracle, Legion Commander, Omniknight.
Omniknight
* Omniknight with Heavenly Grace
* 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.
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.
Omniknight
* Purification prevents Legion Commander from killing her target, and will always hit her during Duels.
* Guardian Angel completely wastes Duel's duration and can save an ally across the map when upgraded with Aghanim's Scepter.
Additional:
* Both Guardian Angel and Purification are perfect counters against Duel.
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
Omniknight
* Although Sven relies often on physical damage, an Aghanim's Scepter upgraded 
Storm Hammer can dispel Guardian Angel with its wide radius.
Omniknight
* Purification can heal allies while dealing pure damage to Sven.
* Heavenly Grace can remove Storm Hammer's debuff immediately or make it a very mediocre stun.
* Guardian Angel negates Sven's massive damage during God's Strength.
* It should also be noted Sven can remove Omniknight's active spells with Aghanim's Scepter.
Keeper of the Light
* Melee carries during the laning phase: Sven, Slark
Omniknight
* Omniknight can dispel Hex or Shackles with Heavenly Grace. He can also heal teammates who you disabled. The same goes for Abaddon's Aphotic Shield.
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 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.
Omniknight
* 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
Keeper of the Light
* Heroes with silences: Puck, Doom, Riki.
Omniknight
* 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.
Keeper of the Light
* Heroes with channeling abilities: Enigma, Witch Doctor, Crystal Maiden.
Omniknight
* Guardian Angel protects allies from Death Ward's physical damage.
* Purification and Heavenly Grace will most likely save teammates from dying to Maledict.
Omniknight
* Heroes with large magical AoE damage will fare well against Omniknight: Lich, Ancient Apparition, Jakiro, Disruptor.
Omniknight
* Purification allows Omniknight to keep a hero trapped in the Static Storm alive.
* Repel is a reliable source of immunity to the effects of Static Storm.
Omniknight
* Heroes who can harass Omniknight out of lane will keep him weak in the mid game: Viper, Venomancer, Clinkz.
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
Omniknight
* Jingu Mastery will still add stacks even through Guardian Angel.
* Monkey King can join a fight whenever he chooses to, meaning he can simply go directly onto Omniknight.
* During the laning phase, Jingu Mastery with Boundless Strike will kill off Omniknight, while Purification is weak.
* Heavenly Grace is useless against Monkey King's ultimate and Jingu Mastery bonuses.
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.
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.
Omniknight
* Guardian Angel's near invulnerability denies Bloodseeker the bonuses from Thirst, preventing him from gaining the upper hand in teamfights.
* Purification's pure damage makes it hard for Bloodseeker to pursue enemies, and prevents him from replenishing his health by finishing off enemies.
Omniknight
*
Global Silence takes Omniknight out of the fight completely.
Glaives of Wisdom are a great harass vs Omniknight during the laning stages of the game, since it doesn't aggro creeps & ignores his high base armor. It deals pure damage, which means it can also go through Guardian Angel.
*
* Silencer's intelligence steal can also cause Omniknight to falter in the early phases as it reduces his ability to use his 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.