Lifestealer
[wiki] rating: 1.6 (winrate: 48% pickrate: 5%)Razor
[wiki] rating: 1.0 (winrate: 54% pickrate: 6%)Underlord
* 
Static Link greatly reduces Underlord damage, while benefits Razor himself, even when in Atrophy Aura's range.
* Underlord is a slow and low mobility hero, and cannot outrun Razor's high movement speed, easily for Razor to absorb his damage with Static Link to the maximum and burst him down from the bonus damages, combine with the armor reduction from 
Eye of the Storm
Nyx Assassin
[wiki] rating: 1.0 (winrate: 54% pickrate: 7%)Keeper of the Light
* 
Mana Burn is strong against Keeper of the Light due to his high mana pool.
* 
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.
Night Stalker
[wiki] rating: 1.0 (winrate: 52% pickrate: 5%)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, who relies on daytime to be effective.
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.
Ursa
[wiki] rating: 1.0 (winrate: 51% pickrate: 16%)Underlord
* Provided Ursa can stack Fury Swipes reliably, Atrophy Aura won't do much against it.
* With Overpower, Fury Swipes, and Enrage Ursa could kill Underlord before the latter escapes with 
Dark Rift.
Additional:
* 
Fury Swipes damage is not reduced by Atrophy Aura, essentially bypassing Underlord's only natural defense.
* 
Enrage can quickly dispel the root of Pit of Malice.
Outworld Destroyer
[wiki] rating: 1.0 (winrate: 51% pickrate: 13%)Underlord
* 
Arcane Orb 's pure damage can do great damage to Underlord.
* 
Sanity's Eclipse can tear down Underlord's health by a large amount, since his mana pool is very low compare to OD's high mana pool.
Luna
[wiki] rating: 1.0 (winrate: 51% pickrate: 7%)Underlord
* 
Lunar Blessing gives allies bonus damage and armor required to endure against Atrophy Aura early on.
* 
Eclipse can be devastating for Underlord's team when they're grouped up for Dark Rift, it can also be used to intercept arrivals with Dark Rift. And Pit of Malice does not prevent Luna to use it.
* To make things even better, Aghanim's Scepter upgraded Eclipse can finish off Underlord or any of his teammates escape attempts with Dark Rift if timed correctly.
Additional:
* Lunar Blessing gives allies bonus damage required to endure against Atrophy Aura early on.
* Eclipse can be devastating for Underlord's team when they're grouped up for Dark Rift, it can also be used to intercept arrivals with Dark Rift. And Pit of Malice does not prevent Luna from using it.
* To make things even worse, Aghanim's Scepter upgraded Eclipse can finish off Underlord or any of his teammates escape attempts with Dark Rift if timed correctly.
Io
[wiki] rating: 1.0 (winrate: 51% pickrate: 7%)Underlord
* Io can escape from Pit of Malice with Tether or Relocate.
* Relocate can counter Dark Rift's split pushing.
Necrophos
[wiki] rating: 1.0 (winrate: 50% pickrate: 3%)Underlord
* 
Reaper's Scythe and 
Heartstopper Aura deal percentage-based damage, ignoring Underlord's high health.
Disruptor
[wiki] rating: 1.0 (winrate: 49% pickrate: 9%)Underlord
* 
Glimpse will return Underlord or any of his teammates attempting to escape with Dark Rift if timed correctly.
* Underlord is a slow and low mobility hero, easy to set up 
Static Storm and 
Kinetic Field, preventing him from using his abilities as well as preventing him using Dark Rift to escape
Winter Wyvern
[wiki] rating: 1.0 (winrate: 49% pickrate: 7%)Underlord
* 
Winter's Curse and 
Splinter Blast can devastate Underlord's team when they're grouped up for Dark Rift.
Shadow Fiend
[wiki] rating: 1.0 (winrate: 46% pickrate: 18%)Underlord
* Shadow Fiend can still dish out heavy damage with 
Requiem of Souls and 
Shadowraze while caught in Pit of Malice.
Rubick
[wiki] rating: 1.0 (winrate: 46% pickrate: 16%)Underlord
* All of Underlord's abilities are useful for Rubick to 
Spell Steal.
Kunkka
[wiki] rating: 1.0 (winrate: 44% pickrate: 3%)Underlord
* 
X Marks the Spot will return Underlord or his teammate if they escape with Dark Rift.
Bane
[wiki] rating: 0.6 (winrate: 54% pickrate: 3%)Underlord
* Heroes that wish to disrupt fights with spell combos or big ultimates are vulnerable to the long stun of Fiend's Grip: 
Disruptor, 
Death Prophet, 
Enigma, 
Faceless Void, 
Invoker, 
Lich, 
Magnus, 
Mars, 
Medusa, 
Outworld Destroyer, 
Phoenix, 
Puck, 
Queen of Pain, 
Shadow Fiend, 
Treant Protector, 
Underlord, 
Winter Wyvern, 
Witch Doctor, 
Zeus.
Clinkz
[wiki] rating: 0.6 (winrate: 53% pickrate: 4%)Keeper of the Light
* Heroes that can jump and kill him: 
Meepo, 
Clinkz, 
Templar Assassin
Huskar
[wiki] rating: 0.6 (winrate: 52% pickrate: 3%)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.
Clockwerk
[wiki] rating: 0.6 (winrate: 52% pickrate: 7%)Underlord
* Heroes with long cast animations can be continuously interrupted by Battery Assault: 
Centaur Warrunner, 
Jakiro, 
Leshrac, 
Naga Siren, Underlord.
Puck
[wiki] rating: 0.6 (winrate: 52% pickrate: 17%)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.
Hoodwink
[wiki] rating: 0.6 (winrate: 52% pickrate: 15%)Underlord
* Durable heroes relied a lot on their main passive effects and items' effects such as 
Bristleback, Underlord, 
Spectre and 
Dragon Knight can be disabled easily with 
Sharpshooter's break, reducing their potential in teamfights.
Oracle
[wiki] rating: 0.6 (winrate: 51% pickrate: 10%)Keeper of the Light
* Heroes with dispels: 
Legion Commander, 
Oracle, 
Slark
Lion
[wiki] rating: 0.6 (winrate: 50% pickrate: 17%)Keeper of the Light
* Mana Drain is very effective against heroes that have mana burn abilities such as 
Anti-Mage, 
Nyx Assassin and Keeper of the Light.
Treant Protector
[wiki] rating: 0.6 (winrate: 49% pickrate: 5%)Underlord
* In general, heroes that provide vision will see Dark Rift coming: 
Techies, Templar Assassin, Treant Protector
Sniper
[wiki] rating: 0.6 (winrate: 49% pickrate: 6%)Underlord
* Heroes who Sniper can kite: 
Sven, 
Wraith King, 
Kunkka, 
Doom, 
Tidehunter, Underlord, 
Troll Warlord, and etc.
Additional:
* Sniper's very long range allows him to stay out of Firestorm and Pit of Malice as well as Atrophy Aura range.
Storm Spirit
[wiki] rating: 0.6 (winrate: 49% pickrate: 12%)Keeper of the Light
* Heroes with teleports to escape Will-O-Wisp: 
Phantom Assassin, Puck, Queen of Pain, 
Storm Spirit
Queen of Pain
[wiki] rating: 0.6 (winrate: 47% pickrate: 9%)Keeper of the Light
* Heroes with teleports to escape Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
Phantom Assassin
[wiki] rating: 0.6 (winrate: 45% pickrate: 16%)Keeper of the Light
* Heroes with teleports to escape Will-O-Wisp: Phantom Assassin, Puck, Queen of Pain, Storm Spirit
Juggernaut
[wiki] rating: 0.4 (winrate: 52% pickrate: 19%)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.
Underlord
* In general, heroes with spell immunity abilities won't be caught inside by Pit of Malice: 
Juggernaut, 
Lifestealer.
Underlord
* Heroes with abilities that can save teammates are also effective such as 
Shadow Demon, 
Dazzle, Oracle, 
Bane, 
Pugna, 
Tusk, Winter Wyvern, 
Io, Underlord, Treant Protector and Keeper of the Light.
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.
Templar Assassin
[wiki] rating: 0.2 (winrate: 51% pickrate: 5%)Underlord
* In general, heroes that provide vision will see Dark Rift coming: Techies, Templar Assassin, Treant Protector
Keeper of the Light
* Heroes that can jump and kill him: Meepo, Clinkz, Templar Assassin
Underlord
* Firestorm will destroy 
Refraction charges very quickly.
* Firestorm will hit Templar Assassin while 
Melded.
* Templar Assassin has a hard time maneuvering around Pit of Malice.
Nature's Prophet
[wiki] rating: -1.6 (winrate: 44% pickrate: 5%)Underlord
* 
Firestorm quickly kills all the treants and increases the 
Atrophy Aura passive.
* 
Pit of Malice can stop Teleportation channeling.
* Atrophy Aura greatly reduces Nature's Prophet's damage and he has no other ways of dealing damage.
* Dark Rift can counter split-pushing, which is something that Nature's Prophet relies a lot, and Nature's Prophet has very little solutions to intercept Dark Rift.
Keeper of the Light
* Heroes that have AoE damage: Lina, Keeper of the Light, 
Timbersaw, Leshrac, Bristleback, 
Axe
Spirit Breaker
[wiki] rating: -1.6 (winrate: 51% pickrate: 8%)Underlord
* Pit of Malice can be cast in the path of Spirit Breaker's Charge of Darkness to cancel it.
* Dark Rift provides a way to escape from a gank for Underlord and his teammates.
Keeper of the Light
* Heroes that punish mobile heroes: 
Bloodseeker, Keeper of the Light
Wraith King
[wiki] rating: -1.6 (winrate: 51% pickrate: 17%)Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, 
Tiny, Wraith King, Dragon Knight, Meepo, Doom, 
Bounty Hunter, 
Dark Seer, 
Undying, 
Alchemist, Legion Commander.
Keeper of the Light
* Wraith King's poor mobility makes him vulnerable to Illuminate.
* Blinding Light can reduce his damage output as well as his already abysmal mobility.
* Chakra Magic drains Wraith King's much-needed mana resulting in him not being able to reincarnate
Sven
[wiki] rating: -1.2 (winrate: 43% pickrate: 1%)Keeper of the Light
* Keeper of the Light's AoE blind can keep Sven from landing hits.
Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.
Pangolier
[wiki] rating: -1.2 (winrate: 49% pickrate: 12%)Underlord
* Heroes with powerful rooting abilities will disable most of Pangolier's skill, a bonus point if it pierce spell immunity since it will also be able to stop Pangolier during his Rolling Thunder: Treant Protector, Meepo, Crystal Maiden, 
Dark Willow, Underlord, Naga Siren
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
Medusa
[wiki] rating: -1.0 (winrate: 45% pickrate: 2%)Keeper of the Light
* 
Chakra Magic can drain her current mana, draining away her effective health in a sneaky way.
* Will-O-Wisp will keep Medusa busy after she got hit by Blinding Light.
Lone Druid
[wiki] rating: -1.0 (winrate: 46% pickrate: 1%)Underlord
* Firestorm's percentage damage can quickly demolish the Spirit Bear's high HP
* Pit of Malice will allow allies to easily kite Lone Druid due to his low mobility
Mars
[wiki] rating: -1.0 (winrate: 48% pickrate: 16%)Underlord
* Firestorm and Pit of Malice are very disruptive in team fights, completely matching Mars especially since it can all be cast inside Arena Of Blood and also does percentage-based magical damage, negating Bulwark.
* Dark Rift can save any allies of Underlord trapped in Arena Of Blood.
* Atrophy Aura allows Underlord to lane against Mars quite well since he does not have the best base damage during the early game.
* Underlord is a common carrier of both 
Pipe of Insight and 
Mekansm/
Guardian Greaves, allowing his team to combat Mars in the mid to late game.
Riki
[wiki] rating: -1.0 (winrate: 48% pickrate: 5%)Underlord
* Pit of Malice prevents Riki from casting Blink Strike or Tricks of the Trade.
* Atrophy Aura reduces Riki's damage.
* Firestorm can be used to harrass Riki in lane.
Venomancer
[wiki] rating: -1.0 (winrate: 50% pickrate: 5%)Underlord
* Dark Rift allows Underlord to transport allies from poison damage-over-time to the fountain.
* Underlord usually buys Pipe of Insight that gives a magic resistance to allies, inhibiting the damage from Venomancer abilities.
Bloodseeker
[wiki] rating: -1.0 (winrate: 51% pickrate: 4%)Underlord
* Damage reduction from Atrophy Aura prevents Bloodseeker from killing targets and gaining his Thirst bonuses.
* Pit of Malice's area of effect catches Bloodseeker easily, negating his speed bonus during teamfights.
* Dark Rift allows Underlord to transport Ruptured allies to the fountain, rendering it useless.
Troll Warlord
[wiki] rating: -1.0 (winrate: 52% pickrate: 12%)Underlord
* Atrophy Aura decreases Troll Warlord's damage.
* Pit of Malice helps lock down Troll Warlord.
* Battle Trance disallows Troll from running out of both Firestorm and Pit of Malice.
Chen
[wiki] rating: -1.0 (winrate: 52% pickrate: 0%)Underlord
* Firestorm will easily clear Chen's creeps.
* Pit of Malice will trap Chen and render him helpless.
* Atrophy Aura gives bonus damage to Underlord for each killed creep and weakens Chen's damage.
* Dark Rift can counter Chen's pushing attempts, and he has nothing to intercept it.
Beastmaster
[wiki] rating: -1.0 (winrate: 53% pickrate: 6%)Keeper of the Light
* Illuminate clears Beastmaster's summons and is effective against his push.
Enigma
[wiki] rating: -1.0 (winrate: 55% pickrate: 8%)Keeper of the Light
* Ezalor's Chakra Magic will drain Enigma's mana pool rather quickly and won't let him chase or initiate with Black Hole properly.
* Will-O-Wisp will disable any close caster like Enigma, forcing him have to keep his Eidolons at maximum count and keep a safe distance.
* Illuminate can wipe the pushing Eidolons in a lane with ease, diminishing Enigma's laning presence by a lot.
Faceless Void
[wiki] rating: -0.6 (winrate: 41% pickrate: 3%)Keeper of the Light
* Any hero that can nullify effects of Chronosphere: (
Omniknight, 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.
Magnus
[wiki] rating: -0.6 (winrate: 44% pickrate: 4%)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.
Morphling
[wiki] rating: -0.6 (winrate: 46% pickrate: 12%)Underlord
* Underlord's Atrophy Aura reduces Morphling's high base damage gained through agility shift.
Terrorblade
[wiki] rating: -0.6 (winrate: 46% pickrate: 4%)Keeper of the Light
* Keeper of the Light can stall pushes with {Ability ID:Illuminate|Keeper of the Light} this makes him strong against pushing heroes: 
Terrorblade Naga siren 
Nature's Prophet and Anti-Mage
Legion Commander
[wiki] rating: -0.6 (winrate: 47% pickrate: 11%)Keeper of the Light
* 
Press the Attack can dispel the blind from Blinding Light from a hero.
* 
Duel can be used to instantly take Keeper of the Light out of a team-fight.
Underlord
* Atrophy Aura's percentage-based damage reduction greatly diminishes Legion Commander's overall damage output, even if she has won many Duels.
* Dark Rift can be used to save Underlord or his allies from Duels if properly timed.
Additional:
* Atrophy Aura makes it hard for Legion Commander to win Duels.
* Dark Rift can be used to save Underlord and his allies from a 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
Drow Ranger
[wiki] rating: -0.6 (winrate: 47% pickrate: 4%)Underlord
* Underlord can not only cancel Marksmanship's aura, but his Atrophy Aura also decreases Drow Ranger's attack damage.
Additional:
* Atrophy Aura reduces Drow Ranger's damage significantly, as she relies on agility.
Dragon Knight
[wiki] rating: -0.6 (winrate: 48% pickrate: 4%)Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.
Slark
[wiki] rating: -0.6 (winrate: 48% pickrate: 13%)Keeper of the Light
* Heroes with dispels: Legion Commander, Oracle, Slark
Underlord
* Heroes with AoE abilities will hit Slark in Shadow Dance: Lina, Jakiro, Underlord, Leshrac, Dark Seer, 
Earthshaker, Timbersaw, Crystal Maiden
Keeper of the Light
* Melee carries during the laning phase: Sven, Slark
Anti-Mage
[wiki] rating: -0.6 (winrate: 49% pickrate: 13%)Keeper of the Light
* Keeper of the Light can stall pushes with {Ability ID:Illuminate|Keeper of the Light} this makes him strong against pushing heroes: Terrorblade Naga siren Nature's Prophet and Anti-Mage
Undying
[wiki] rating: -0.6 (winrate: 50% pickrate: 4%)Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.
Phantom Lancer
[wiki] rating: -0.6 (winrate: 51% pickrate: 10%)Underlord
* Heroes that require burst damage to kill will be difficult for Phantom Lancer to take down: Timbersaw, Axe, Bristleback, Alchemist and Underlord
Additional:
* Firestorm is very useful for clearing multiple illusions swiftly.
* Pit of Malice will continuously disrupt many illusions, drastically reducing their damage and potency.
* Athropy Aura reduces damage of both Phantom Lancer and his illusions.
Dark Seer
[wiki] rating: -0.6 (winrate: 51% pickrate: 3%)Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.
Alchemist
[wiki] rating: -0.6 (winrate: 53% pickrate: 14%)Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.
Naga Siren
[wiki] rating: -0.6 (winrate: 54% pickrate: 2%)Keeper of the Light
* Keeper of the Light can stall pushes with {Ability ID:Illuminate|Keeper of the Light} this makes him strong against pushing heroes: Terrorblade Naga siren Nature's Prophet and Anti-Mage
Bounty Hunter
[wiki] rating: -0.6 (winrate: 54% pickrate: 10%)Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.
Lycan
[wiki] rating: -0.6 (winrate: 54% pickrate: 3%)Keeper of the Light
* Keeper of the Light has a blind, which causes Lycan to miss his attacks.
Doom
[wiki] rating: 0.0 (winrate: 44% pickrate: 2%)Underlord
* An Aghanim's Scepter upgraded 
Doom can be useful against heroes with troublesome passive skills while also disabling them for a long time: Phantom Assassin, 
Enchantress, Huskar, Underlord.
Additional:
* 
Infernal Blade does damage based on percentage health, and is useful against high health pool hero like Underlord
* Doom can prevent Underlord from spamming his abilities and most important is prevent him from using Dark Rift to escape
Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.
Tiny
[wiki] rating: 0.0 (winrate: 45% pickrate: 5%)Keeper of the Light
* Squishy heroes, usually supports, like Io, 
Ancient Apparition, Keeper of the Light etc can die instantly from Tiny's magic burst.
Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.
Meepo
[wiki] rating: 0.0 (winrate: 45% pickrate: 1%)Keeper of the Light
* Heroes that can jump and kill him: Meepo, Clinkz, Templar Assassin
Underlord
* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.
Techies
[wiki] rating: 0.0 (winrate: 48% pickrate: 8%)Underlord
* In general, heroes that provide vision will see Dark Rift coming: Techies, Templar Assassin, Treant Protector
Keeper of the Light
* Heroes with flying vision such as 
Visage, 
Beastmaster, Keeper of the Light, or 
Night Stalker can scout your mines from outside their trigger radius.
Monkey King
[wiki] rating: 0.0 (winrate: 50% pickrate: 16%)Underlord
* Firestorm will do little percentage damage to a small HP hero like Monkey King.
* All aspects of Jingu Mastery benefits ignore Atrophy Aura's base damage reduction.
* Monkey King can get on top of Underlord easily at any stage of the game.
Keeper of the Light
* Blinding Light can easily push Monkey King out of Wukong's Command, as well as blinding him.
* Will-O-Wisp destroys trees in a massive area, damaging Monkey King's mobility
* However, Keeper of the Light can be easily ganked by Monkey King during early-mid game stage.
Additional:
* Blinding Light can knock Monkey King outside of his ultimate, Wukong's Command or can generally blind him effectively.
* Will-O-Wisp stun Monkey King from Tree Dance by destroying his tree.
Underlord
* In general, heroes with spell immunity abilities won't be caught inside by Pit of Malice:
Juggernaut, 
Lifestealer.
Keeper of the Light
*
Rage allows him to dispel Blinding Light from himself.
Open Wounds allows him to slow and kill Keeper of the Light.
*