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

* Thirst prevents Slark from healing with Shadow Dance.
* Rupture will deal damage during Pounce.
* Dark Pact cannot dispel Rupture, preventing Slark from escaping ganks.
Additional:
* Thirst makes Slark visible while at low health, canceling out Shadow Dance's passive. For this reason, Bloodseeker is usually considered the hardest counter to Slark.
* Rupture cannot be dispelled by Dark Pact, and using Pounce while affected by it will cause Slark to take damage.

* 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.

* Every Meepo clone adds to Thirst's bonuses.
* Bloodseeker can chase down retreating clones when Meepo tries to cycle weaker clones away from combat.

* 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

* Thirst provides constant sight and speed to Bloodseeker, allows him to catch up a fleeing Pangolier through all of his mobility.
* Rupture is a great threat to Pangolier, causes him to take heavy damage if he uses Swashbuckle and especially Rolling Thunder, forcing him to stop his ultimate prematurely, or keep rolling to his death.
Additional:
* Rupture works through Rolling Thunder and Swashbuckle, greatly reducing Pangolier's 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.

* Bloodseeker's Rupture can turn Bounty Hunter's mobility against him, and prevents him from escaping with Shadow Walk due to the potentially heavy damage.
* Thirst can prevent Bounty Hunter from escaping with Shadow Walk should Bounty Hunter's health become low enough.

* Heroes with fast movement abilities will suffer huge damage when afflicted by Rupture: Spirit Breaker, Earth Spirit, Dark Seer.

* 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 fast movement abilities will suffer huge damage when afflicted by Rupture: Spirit Breaker, Earth Spirit, Dark Seer.

Additional:
* Rupture can deal a lot of damage to either a surged Dark Seer or his allies and prevent the target to get into position.

* 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.

* 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.

* Firestorm will clear easily 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.

* Blood Rite prevents Queen of Pain from escaping with Blink.
* Blink will trigger the extra damage from Rupture.
Additional:
* Bloodrage is the best tool to pop her spell block talent or her Linken's Sphere, following up with Rupture.
* Blood Rite silences her, preventing her from initiating or escaping.
* With Thirst, even if she Blinks away, Bloodseeker can catch right up to her.
* Rupture will heavily damage Queen of Pain if she tries to Blink away.
* She is, however, one of the few heroes who can avoid the damage from Rupture if she does it correctly.

* Rupture deals extra damage to Magnus during Skewer or Force Staff, preventing him from escaping or counter-initiating, forcing him to invest on a Linken's Sphere.

* 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.

* Heroes with invisibility will be detected by Thirst when they have low enough health: Bounty Hunter, Templar Assassin, Riki, Clinkz, Weaver, Treant Protector, Nyx Assassin.

* Although Blood Rite can be easily avoided, if it does hit, its lengthy silence and pure damage can be a severe punishment for a slow, unobservant, or simply unfortunate Phoenix. His Rupture can turn Icarus Dive into a suicide option, and it cannot be dispelled, meaning even if Phoenix completes a Supernova, choosing to Dive may just cut its health back down. And finally, due to Phoenix's health costs, too much careless ability spamming may just put Phoenix into Bloodseeker's vision, making it a very tempting ganking target.
Additional:
* Phoenix expends health to use its abilities, making it a good target for Thirst.
* Rupture deals heavy damage against Icarus Dive.

* Shukuchi will trigger extra damage from Rupture.
* Shukuchi's invisibility is detected by Thirst.
* Time Lapse cannot dispel Rupture, preventing Weaver from escaping ganks.
Additional:
* Rupture is particularly crippling against Weaver, who relies on high movement speed from Shukuchi to fight and escape, and it cannot be dispelled by Time Lapse.
* Thirst detects Weaver through Shukuchi whenever his health is low.
* Blood Rite combined with Rupture forces Weaver to either take damage from the latter, or to get silenced for a long duration.
* Bloodrage is a good tool to pop Weaver's Linken's Sphere to follow up with Rupture.

* 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.

* Bloodseeker natural attack, run and turn speed outpaces viper's and makes viper easy pickings for Bloodseekers top

* If Thirst activated, Lich doesn't slow Bloodseeker.
* If he sees Chain Frost is targeting him, he can easily isolate himself with Thirst or forces Bloodseeker to build Blade Mail can cause Lich to accidentally kill himself with Chain Frost.
* Even Lich builds Glimmer Cape or Force Staff are suicidal item against Bloodseeker when he is affected by Rupture.

* Rupture turns Windranger's mobility against her.
Additional:
* Windrun triggers the damage from Rupture.

* Rupture will fully damage Void Spirit during his ultimate, removing his main escape mechanic during fights and his way to disrupt them heavily.
* Blood Rite will force Void Spirit to use Dissimilate or Astral Step or be silenced. In the latter's case, it can be dangerous when combined with Rupture.

* Huskar is often at low health, providing large Thirst bonuses to Bloodseeker.
* Life Break can trigger Rupture's damage.
* A self applied Bloodrage together with Blademail means it's almost suicidal for Huskar to jump on Bloodseeker with Life Break
Additional:
* Huskar is often at low health, providing large Thirst bonuses.
* Life Break triggers Rupture's damage.

* Rupture completely negates Lycan's high mobility.
* All of Lycan's summons are good sources of healing with Bloodrage.
Additional:
* Rupture completely negates Lycan's high mobility.
* All of Lycan's summons are good sources of healing with Bloodrage.

* Blood Rite can flush Enigma out of position and potentially force him to activate his spell immunity prematurely, before pulling off a Black Hole combo.
* Bloodseeker can find an Enigma out of position and Rupture him, making it difficult to initiate properly in a team fight, as it pierces through Black King Bar

* Blood Rite can silence Warlock, which as a spellcaster is bad for him.
* Rupture prevents Warlock from moving without taking damage, which due to his general lack of escapes is bad for him, and when combined with Blood Rite can be a very lethal combo.

* Rupture deals damage through Blink, dissuading Anti-Mage from using it. This allows Bloodseeker to get early kills on Anti-Mage, preventing him from snowballing.
* However, Anti-Mage is one of the few heroes who can avoid the damage from Rupture if he does it correctly.
* Blood Rite silences Anti-Mage during teamfights, preventing him from Blinking away.
* Bloodseeker's abilities also deal pure damage, which bypasses Counterspell.
Additional:
* Blood Rite prevents Anti-Mage from escaping with Blink.
* Blink will trigger the damage from Rupture.
* Both Blood Rite & Rupture are pure damage which can bypass Counterspell.

* 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.

* Rupture can quickly kill Mirana if she tries to Leap away.
* Thirst detects Mirana and her allies during Moonlight Shadow.
Additional:
* Thirst detects Mirana or her ally at low health during Moonlight Shadow.
* Rupture deals high damage when Mirana uses Leap.

* Thirst detects Riki whenever his health is low.
* Rupture does large damage when Riki uses Blink Strike.

* Nether Swap triggers extra damage from Rupture.
* Blood Rite sets up while Vengeful Spirit using her Nether Swap within a timed correctly.

* Skeleton Walk is not enough to outrun Bloodseeker, and is detected by Thirst.
Additional:
* Thirst reveals Clinkz if he tries to escape with Skeleton Walk with low health. It also allows Bloodseeker to match or exceed Clinkz's speed.
* Rupture negates the mobility provided by Skeleton Walk in any attempt to escape or reposition in fights.
* Bloodseeker can easily build items to counter Clinkz, including Talisman of Evasion upgrades, Blade Mail, and armor items.

* Bloodseeker's Rupture shows a clear red trail effect on the real Phantom Lancer.
* Heroes with undispellable debuffs will help identify the real Phantom Lancer through visual effects or debuff indicators, provided that it was cast on the real Phantom Lancer to begin with:
* Doom's Doom marks Phantom Lancer with a highly visible effect, and also silences him.
* Bloodseeker's Rupture shows a clear red trail effect on the real Phantom Lancer.
* Ancient Apparition's Ice Blast will only debuff Phantom Lancer and not his illusions.
* Grimstroke's Soulbind is undispellable.
* Shadow Demon's Demonic Purge is undispellable.
* Monkey King's Jingu Mastery is undispellable and puts a big yellow Mark over his head.

* 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, 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 long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker.

* Heroes with invisibility will be detected by Thirst when they have low enough health: Bounty Hunter, Templar Assassin, Riki, Clinkz, Weaver, Treant Protector, Nyx Assassin.

Additional:
* While Burrowing, Nyx is an easy target for a Blood Rite, although he can at least partially counter it with a well-timed Spiked Carapace.
* Thirst is always a threat to Nyx Assassin, hindering his attempt of escape using Vendetta.
* Rupture also prevents Nyx Assassin from escaping with Vendetta, as it forces him to stay still.

* Bloodseeker's Rupture deals great damage against Timbersaw should he tried escaping with Timber Chain.

Additional:
* Rupture and Blood Rite locks down Timbersaw, preventing him from escaping with Timber Chain. However, Timbersaw may reflect a good deal of damage with Blade Mail.

* Heroes with fast movement abilities will suffer huge damage when afflicted by Rupture: Spirit Breaker, Earth Spirit, Dark Seer.

* Heroes with good mobility to avoid Jakiro's abilities and with good chase to punish Jakiro from pushing a tower: Bloodseeker, Ember Spirit, Juggernaut, Phantom Assassin, Weaver.

* 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.

* Bloodseeker's Rupture forces Slardar to stay still during fights, preventing Slardar from using Guardian sprint to move in and out of fights. This takes away the ability to initiate and re-initiate with Slithereen Crush's low cooldown. Due to the increased move speed from Guardian Sprint, Slardar can lose health at about 160% the rate of normal heroes while under Rupture. Bloodseeker's Thirst also gives him enough move speed that he's one of the few heroes who can outrun or catch up to a Slardar during Sprint.

* 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.

* Bloodseeker's Rupture turns Night Stalker mobility against him and Thirst grants movement speed bonus and vision prevents Night Stalker from initiating and re-initiating.

* As a spellcaster, silences will nullify him entirely. Some notable examples are Death Prophet, Drow Ranger, Bloodseeker, Disruptor and many others.
* Doom, as usual, fits this description nicely.

* 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.

* Sniper is suspectible to being ganked by Bloodseeker, who can easily kill Sniper due to his lack of mobility and escape mechanisms.
* Even if Sniper builds mobility items, Bloodseeker can prevent and even punish Sniper from/for using them with Rupture; Sniper is forced to stand still with Shadow Blade, while Hurricane Pike and Blink Dagger deals damage if he attempts to use them while Ruptured.
Additional:
* Sniper's lack of mobility and escape mechanisms makes him one of the easier heroes for Bloodseeker to gank.

* Thirst allows Bloodseeker to see where Io relocated to, should either Io or the tethered hero have low health.
* Rupture forces Io to stay in place, preventing it from using the Tether bonus movement speed to escape.

* 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.

* 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.

* Heroes with abilities that can save are also effective such as Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.

* Heroes with invisibility will be detected by Thirst when they have low enough health: Bounty Hunter, Templar Assassin, Riki, Clinkz, Weaver, Treant Protector, Nyx Assassin.