* 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.

* Heroes that can deny Slark early kills will prevent him from snowballing: Dazzle, Abaddon

* Heroes with abilities that reduce armor will make Huskar very vulnerable: Weaver, Dazzle, Bristleback, Vengeful Spirit.

* 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.

* 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.

* Heroes that excel at grouping up with their team very early will be able to take advantage of a Clinkz that tries to pick off heroes that are alone: Brewmaster, Dazzle, Tidehunter.

* Heroes that can slow Charge of Darkness by a huge amount: Venomancer, Viper, Dazzle, Arc Warden

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

* 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.

* 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.

* Shallow Grave saves an ally whom Terrorblade has used Sunder on.

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

* 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.

* 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.

* 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.

* 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.

* Shallow Grave prevents Legion Commander from killing her opponents in Duels.
* Shadow Wave will heal an ally caught in a Duel, as well as dealing damage to Legion Commander.

* 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.

* 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.

* 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.

* Venomancer's damage-over-time abilities are easier to heal through with numerous Shadow Waves than other types of damage, and it's simple to time a Shallow Grave until the last possible second to save a teammate from them.

* 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.

* Heroes that can maintain vision on Monkey King can see when he uses Tree Dance: Bloodseeker, Treant Protector with Eyes In The Forest, Sniper, Weaver

* Hand of God has a long cooldown, so damage over time spells can be hazardous for Chen, forcing him to use it prematurely: Jakiro, Venomancer, Viper, Dazzle, Phoenix.

* Heroes with silences : Bloodseeker, Riki, Silencer.

* 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.

* 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.

* Heroes with armor reducing abilities greatly hinder Visage's defense like Slardar and Dazzle.

* 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.

* 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.

* 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.

* 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.

* Dazzle's Shadow Wave is a spammable healing ability that spreads around his entire team, slowing the death of his teammates as effectively as Necrophos spreads damage to them.
* If not immediately, Shallow Grave delays his ally from gradually dying to Necrophos' abilities, especially Reaper's Scythe.
Additional:
* Reaper's Scythe is very predictable and gives you plenty of time to react with Shallow Grave: just keep a close eye on allies below 50% health.
* However, be sure to use Shadow Wave on that ally immediately after, or they will die from Heartstopper Aura when the Shallow Grave ends!

* Shadow Wave will hit Clockwerk every time when he's fighting with an enemy inside Power Cogs.
* Due to Clockwerk's slow damage output, Dazzle will have more than enough time to Shallow Grave any enemy Clockwerk initiates on.
Additional:
* Shadow Wave will hit Clockwerk every time when he's fighting with an enemy inside Power Cogs.
* Due to Clockwerk's steady damage output, Dazzle has plenty of time to Shallow Grave anyone Clockwerk initiates on.

* Shadow Wave provides good sustain against Tinker's spammable abilities.
* Shallow Grave can stop Tinker from bursting down a target.

* Shallow Grave can be used to save an ally during Dismember and Rot.
* A combination of Bad Juju, Poison Touch, and items like Desolator or Solar Crest can tear off Pudge's low armor, making him even more vulnerable to physical damage.

* 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.