From Dota 2 Wiki
- Mana Break quickly depletes Bristleback's low mana, denying him the ability to spam Quill Spray and Viscous Nasal Goo.
- Infernal Blade deals scaling damage and is useful against high health targets such as Bristleback.
- Doom disables Bristleback's low cooldown abilities, preventing him from triggering Warpath. With Aghanim's Scepter, it also breaks Bristleback's passive, rendering him more vulnerable.
- Nature's Attendants provide a good source of healing, countering Quill Spray during the early game.
- Impetus' pure damage works well against Bristleback's tankiness.
- Time Dilation prevents Bristleback from spamming his low-cooldown abilities, greatly reducing his damage and effectiveness.
- Chronosphere allows allies to resposition and hit Bristleback from the front, bypassing his defensive bonus from behind.
- Mana Leak greatly hinders Bristleback's chasing abilities as well as damage output.
- Duel makes Bristleback fight Legion Commander face to face, forcing him to take full damage.
- Press the Attack dispels the slow from stacks of Viscous Nasal Goo.
- Mana Drain is a headache for Bristleback to deal with during the laning stage, as it denies him the ability to get last hits with Quill Spray.
- Finger of Death deals high damage to Bristleback, and only triggers his passive once.
- Reaper's Scythe and Heartstopper Aura deal percentage-based damage, ignoring Bristleback's high health.
- Heartstopper Aura's HP removal does not trigger Bristleback's passive.
- Outworld Devourer's heavy pure damage output penetrates Bristleback's tanky items.
- Sanity's Eclipse only triggers Bristleback's passive once, and deals high damage against Bristleback's low intelligence.
- Eye of the Storm melts Bristleback's armor, and makes him much less tanky.
- Static Link can completely drain Bristleback's bonus damage from Warpath.
- Arcane Curse stacks every time Bristleback uses an ability, forcing him to stop spamming his abilities, or take heavy health degeneration.
- Glaives of Wisdom's pure damage cuts through Bristleback's tanky items.
- Last Word and Global Silence stops Bristleback from using his abilities altogether.
- Guardian Sprint allows Slardar to outrun Bristleback, even when slowed by Viscous Nasal Goo.
- Corrosive Haze's armor reduction makes Bristleback much less tanky.
- Whirling Death deals damage as well while reducing 15% of Bristleback's strength, which reduces Bristleback's tankiness.
- Reactive Armor can sustain through multiple Viscous Nasal Goo and Quill Spray stacks.
- Timber Chain makes it hard for Bristleback to slow down Timbersaw with Viscous Nasal Goo.
- Nethertoxin disables Bristleback's passive.
- Viper Strike and Poison Attack slow down Bristleback's movement speed so he's unable to get out from Nethertoxin.
- Axe forces Bristleback to turn around with Berserker's Call, allowing allies to attack him without fear of his passive.
- Terrorblade's Sunder is not affected by the Bristleback damage reduction.
- Batrider's turn rate slow from Sticky Napalm makes it harder for Bristleback to keep his back towards the enemy.
- Heroes who deal single instance burst damage will only proc Bristleback once: Lina, Lion
- Magic Stick gains many charges due to Bristleback's constant usage of Quill Spray, giving its holder an advantage in lane.
- Silver Edge removes Bristleback's passive, taking away both his tankiness as well as his damage output.
- Solar Crest reduces Bristleback's armor greatly, allowing teammates to beat him down quickly.
- Assault Cuirass' armor aura reduces Quill Spray's area damage significantly.
- Town Portal Scroll provides an easy means of escape from Bristleback, as he has no disables.
Good against...Arc Warden
- Bristleback need not worry about charging into Magnetic Field, and quickly clearing up Arc Warden's summons and Tempest Double with Quill Spray.
- Quill Spray destroys spiderlings, and hits Broodmother even when she's regenerating in her webs. This makes Bristleback one of her hardest counters in lane.
- Quill Spray quickly destroys Chaos Knight's Phantasms.
- The damage from Burning Spear can be reduced by turning away from Huskar.
- Bristleback can bait Huskar into using Life Break on him, then turn around and receive very little damage.
- Macropyre's frequent damage ticks causes Bristleback to activate repeatedly, resulting in free damage as long as Bristleback faces away from Jakiro.
- Multiple instances of damage from Eclipse will trigger Bristleback's passive repeatedly in a short time, dealing tremendous damage to Luna and her teammates.
- Luna's general lack of burst damage makes it hard for her to take down Bristleback.
- Lycan's wolves deal little damage to Bristleback, and are easily killed by Quill Spray, even when they're invisible.
- Lycan's lack of burst damage makes it very hard for him to kill Bristleback, especially when his back is turned.
- Quill Spray usually hits Meepo's clones, and Bristleback can still turn his back when rooted with Earthbind.
- Quill Spray cleans up Phantom Lancer's illusions in no time.
- Phantom Lancer's complete lack of burst damage makes it nearly impossible for him to kill Bristleback during chases.
- Bristleback is one of the hardest heroes to gank with a Meat Hook and Dismember combo, and attempts to do so sometimes backfire on Pudge.
- Quill Spray will hit Riki even when he is invisible.
- Cloak and Dagger's bonus backstab damage is rendered irrelevant against Bristleback.
- Smoke Screen does not stop Bristleback's passive from activating.
- Due to Bristleback's natural tankiness, he is an ideal Gem of True Sight carrier, directly countering Riki's invisibility.
- Bristleback's abilities are nearly useless for Rubick to Spell Steal, as he does not gain the bonuses from Warpath.
- Quill Spray will hit Sand King inside Sand Storm, damaging him and putting Sand King's Blink Dagger on cooldown, preventing him from escaping.
- Epicenter's numerous damage ticks will trigger Bristleback's passive repeatedly during teamfights.
- Heroes with damage-over-time abilities will not only proc Bristleback's passive continuously, they will also do little harm to him when he is facing away from the source: Venomancer, Arc Warden
Works well with...Crystal Maiden
- Arcane Aura helps Bristleback use Quill Spray more often during the laning stage, allowing him to harass and last hit better.
- Viscous Nasal Goo works well with Crystal Maiden's slowing abilities, keeping enemies in range of Quill Spray and Freezing Field.
- The extra time from Shallow Grave allows Bristleback to get off a few more Quill Sprays due to its low cooldown, and potentially change the outcome of a fight.
- Frost Arrows' slow works well with Viscous Nasal Goo.
- Chakra Magic's cooldown reduction allows Bristleback to Quill Spray twice in a row.
- Essence Aura's mana restoration allows Bristleback to Quill Spray almost indefinitely.
- Concussive Shot's slow stacks well with Viscous Nasal Goo, keeping targets in range of Quill Spray, as well as making it harder for them to move out of Mystic Flare.
- Venomancer's numerous movement speed slows stack well with Viscous Nasal Goo.