* Pit of Malice prevents Phantom Assassin from either escaping or engaging with Phantom Strike.
* Phantom Assassin's damage output is entirely physical, therefore Atrophy Aura Atrophy Aura is very hazardous for her in most of the stages, particularly since it also affects Coup De Grace Coup de Grace, hindering Phantom Assassin's main source of damage.
* Without proper items and any area-of-effect ability/item, Phantom Assassin cannot stop Underlord and his team to escape with Fiend's Gate, nor she can intercept them if Underlord chooses to teleport on any area of the map.
Additional:
* Pit of Malice prevents Phantom Assassin from either escaping or engaging with Phantom Strike.
* Phantom Assassin's damage output is entirely physical, therefore Atrophy Aura Atrophy Aura is very hazardous for her in most of the stages, particularly since it also affects Coup De Grace Coup de Grace, hindering Phantom Assassin's main source of damage.
* Without proper items and any area-of-effect ability/item, Phantom Assassin cannot stop Underlord and his team to escape with Fiend's Gate, nor she can intercept them if Underlord chooses to teleport on any area of the map.

* Phantom Assassin is known to be weak against bursts of magical damage, something Primal Beast excels at from the beginning of the game. He can use this to his advantage by constantly hunting Phantom Assassin down, especially if she is left alone to farm.
* Primal Beast is a good carrier of Ethereal Blade, Vanguard and Shiva's Guard all of which are very good against Coup de Grace and Phantom Strike.
* Even though Primal Beast does alot of physical damage early on, later once Blur becomes more potent, she may find herself being overwhelmed by Trample and Pulverize instead.
* Primal Beast also has a level 25 talent which makes Pulverize go through spell immunity which is especially effective against a hero like Phantom Assassin who relies on it.

* Underlord's Atrophy Aura reduces Morphling's high base damage gained through agility shift.

* Morphling relies on Attribute Shift (Agility Gain) to take last-hits. Primal Beast's burst damage ability can constantly threaten Morphling, especially due to his short attack range. If forced to escape with Waveform, Primal Beast can catch up with Onslaught.

* Atrophy Aura reduces Terrorblade's damage significantly, even during Metamorphosis.
* Firestorm deals significant damage to Terrorblade and his illusions from a safe distance.
* Pit of Malice can keep Terrorblade and his illusions under control.
* Fiend's Gate can either bail out Underlord's team away from a bad engagement against a Terrorblade under Metamorphosis or caught Terrorblade off guard if he is not careful, and besides Reflection, Terrorblade has no other abilities to intercept Underlord nor his team when they use it to start a teamfight.
* Likewise, Fiend's Gate can be used to quickly move Underlord's team to the frontlines, to strike Terrorblade and his allies during Metamorphosis's 150 seconds of cooldown.
Additional:
* Atrophy Aura reduces Terrorblade's damage significantly, even during Metamorphosis.
* Firestorm deals significant damage to Terrorblade and his illusions from a safe distance.
* Pit of Malice can keep Terrorblade and his illusions under control.
* Fiend's Gate can either bail out Underlord's team away from a bad engagement against a Terrorblade under Metamorphosis or caught Terrorblade off guard if he is not careful, and besides Reflection, Terrorblade has no other abilities to intercept Underlord nor his team when they use it to start a teamfight.
* Likewise, Fiend's Gate can be used to quickly move Underlord's team to the frontlines, to strike Terrorblade and his allies during Metamorphosis's 150 seconds of cooldown.

* Illusion heroes will struggle against Primal Beast's area damage capability, such as Chaos Knight, Naga Siren, Terrorblade.

* Firestorm makes quick work of Treants and Atrophy Aura gives him temporary damage for every Treant killed.
* Pit of Malice can stop Teleportation channeling.
* Atrophy Aura greatly reduces Nature's Prophet's damage and he has no other good way to deal damage.
* Fiend's Gate can counter split-pushing, which is something that Nature's Prophet relies on a lot.

* Heroes with unorthodox escapes will struggle against Primal Beast, such as Nature's Prophet, Tinker, and Templar Assassin.

* Atrophy Aura reduces Drow Ranger's damage significantly, as she relies on agility to be effective.

* Heroes who have low armor but very high health will be difficult for drow to burst down quickly: Primal Beast, Axe, Centaur Warrunner.

* Heroes with AoE abilities will hit Slark in Shadow Dance: Lina, Jakiro, Underlord, Leshrac, Dark Seer, Earthshaker, Timbersaw, Crystal Maiden.

* Dark Pact, Shadow Dance and Depth Shroud will do nothing against Onslaught and Trample, as they are both ground area-of-effect spells.
* Primal Beast has a gigantic hitbox, which could be difficult for Slark to escape with Pounce should Primal Beast choose to block him. Pounce also does not completely prevent Primal Beast from trampling offensively, as he still has some room to move.
* Primal Beast has a huge health pool; shedding it with Essence Shift can take time and may allow Primal Beast to build Uproar against him. Should he survive Slark's slew of skills, Primal Beast can simply Pulverize him to finish him off.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* Illusion heroes will struggle against Primal Beast's area damage capability, such as Chaos Knight, Naga Siren, Terrorblade.

* In general, heroes with long cooldowns on their abilities or ultimate will struggle against the relentless pressure provided by Dark Rift or Fiend's Gate (Requires Aghanim's Scepter): Terrorblade, Dragon Knight, Omniknight.

* Heroes who cannot escape from Trample early might be easy first blood. Heroes like Witch Doctor and Omniknight should play very cautiously alone...

* 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.

* Trample and Pulverize can be used to cancel Life Drain very quickly.
* Pugna has a very low strength gain and as a support does not have much gold to buy health items, making him vulnerable to Primal Beast's onslaught of magical damage.
* Ironically, Decrepify actually just increases Primal Beast's damage on the targeted ally if Trample is activated. However, it can be used to slow him down and prevent any further Trample damage.

* Firestorm will destroy Refraction charges very quickly.
* Firestorm will hit Templar Assassin while under the effects of Meld Meld.
* Templar Assassin has a hard time maneuvering around Pit of Malice.

* 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...

* 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.

* 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.

* Primal Beast can use Uproar to tank a portion of Omnislash, giving him an edge in surviving it. Primal Beast can also dash away after Omnislash with Onslaught, disallowing Juggernaut from any follow-ups.
* Blade Fury will never do more damage than Uproar once the stacks are activated.
* Primal Beast is very commonly buying items that are good against Juggernaut, such as Ethereal Blade and Heart of Tarrasque.

* Since Primal Beast is highly mobile with Onslaught alone, he will be difficult to catch with both Cold Feet and Ice Blast.
* Ice Blast is less effective due to Primal Beast's massive health pool and resistance to taking damage.
* While Chilling Touch can be used to slow Primal Beast briefly, it is not enough to beat him back, and can also contribute to his Uproar stacks.

* 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.

* Magnus is not tanky and struggles against burst damage, something Primal Beast excels at in the early-to-mid game. Primal Beast is also able to out-damage Magnus's Empower and can even contribute to his Uproar stacks.
* Using Skewer to drag Primal Beast while he is trampling will count as movement and will trigger a rapid number of slams, which could prove lethal to Magnus.

* 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.
* Fiend's Gate can counter Chen's pushing attempts, and he has nothing to intercept it.

* Dispersion reduces damage based on a percentage, which is very minimal against large amounts of small instances of damage such as Trample. It reduces each tick by about 14 at maximum level, which is very small.
* Desolate is never a threat to Primal Beast due to his large health pool and Uproar still out damaging the ability.
* Onslaught can allow Primal Beast to chase Spectre fleeing with Spectral Dagger, as both skills phase through trees and terrain.
* Primal Beast can be strong enough to force a farming Spectre to flee with Haunt, putting it on a long cooldown and potentially leading her to an ally that can finish her off.
* Primal Beast excels at early aggression, pushing weak carries out of lane and farming areas he wants to control. Overall just not a pleasant matchup for Spectre.

* While Broodmother can hide in the trees with Spin Web, Primal Beast's ability to trample trees down can give him an edge in catching her.
* Insatiable Hunger will not do much vs Primal Beast's onslaught of disables.
* While Silken Bola can slow Primal Beast down, it's not enough to stop Trample from doing more damage than Broodmother can do back.
* Spawn Spiderlings will be destroyed by Onslaught and Trample very easily.

* 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.

* In general, heroes with long cooldowns on their abilities or ultimate will struggle against the relentless pressure provided by Dark Rift or Fiend's Gate (Requires Aghanim's Scepter): Terrorblade, Dragon Knight, Omniknight.

* Hard carries who just want to farm and be left alone will not appreciate Primal Beast, heroes such as Medusa, Drow Ranger...

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* Heroes with powerful rooting abilities will disable most of Pangolier's skills, a bonus point if it pierces 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

* Heroes that reduce the damage that Marci can deal during her ultimate, like Razor, Rubick, Bane, Dragon Knight and Underlord.

* Heroes who cannot escape from Trample early might be easy first blood. Heroes like Witch Doctor and Omniknight should play very cautiously alone...

* 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.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* 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...

* Any hero with low mobility and max healthsuch as Silencer, Crystal Maiden etc.

* 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.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* Illusion heroes will struggle against Primal Beast's area damage capability, such as Chaos Knight, Naga Siren, Terrorblade.

* 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.

* Any hero with low mobility and max healthsuch as Silencer, Crystal Maiden etc.

* 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.

* 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.

* Heroes with unorthodox escapes will struggle against Primal Beast, such as Nature's Prophet, Tinker, and Templar Assassin.

* Primal Beast is one of Sniper's greatest counters, as he has no real means of escape and is very squishy, especially in the early game. Sniper's potshots and Shrapnel can contribute to Primal Beast's Uproar and further make him tankier than he already is. Onslaught allows him to close the gap on Sniper at his own volition, and Trample can deal serious damage to his meager health pool. Should Sniper acquire an item of escape, Primal Beast can still delay him with Pulverize. Overall, Sniper is an ideal target for Primal Beast to constantly threaten in all stages of the game, and it can force Sniper to itemise for him.

* 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

* 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.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* 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.

* 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.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* Atrophy Aura's percentage-based damage reduction greatly diminishes Legion Commander's overall damage output, even if she has won many Duels
* Legion Commander cannot get out the way of Firestorm because she is stationary.
Additional:
* Atrophy Aura makes it hard for Legion Commander to win Duels.
* Fiend's Gate can be used to save Underlord and his allies from a Duel or to intercept Legion Commander, because outside from Overwhelming Odds, Legion Commander has no other area-of-effect abilities.

* Onslaught prevents all of Razor's abilities from being effective against him, especially in the laning stage.