* Quill Spray is very effective against Io, as it has very low armor and has to stay close to the fight to not break its Tether.

* Lightning Storm will usually hit both Io and its tethered target since both will be close enough for the lightning to jump.
* Diabolic Edict and Pulse Nova hit all units near Leshrac, meaning he can do colossal damage to Io and its tethered target.
Additional:
* Lightning Storm will usually hit both Io and his Tethered target since both will be close enough for the lightning to jump. It can then be followed up by Split Earth.
* Diabolic Edict and Pulse Nova hit all units near Leshrac, meaning he can do colossal damage to Io and his Tethered target.

* Pulse Nova deals an insane amount of damage in an area around him, which can quickly wear down Meepo clones.
* Leshrac can catch multiple Meepos in Split Earth and follow up with the rest of his area damage spells making meepo unable to get close to leshrac.
* Diabolic Edict is a strong ability that can wear down a lone Meepo clone quickly.

* Quill Spray usually hits Meepo's clones, although Bristleback cannot turn his back when rooted with Earthbind.

* Bristleback's tankiness and damage reduction from the rear makes him very hard for Phantom Lancer to chase and finish off, due to his lack of burst damage.
* Quill Spray destroys Phantom Lancer's illusions.
* Bristleback's passive costs no mana, meaning that it will continue to trigger even if Phantom Lancer drains Bristleback's mana with Diffusal Blade.
Additional:
* 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.

* Leshrac's AoE abilities destroy Phantom Lancer's illusions.
* Diabolic Edict and Pulse Nova require no targeting, thus hitting Phantom Lancer whenever he's nearby.
Additional:
* Leshrac can easily clear Phantom Lancer's illusions with his huge area of effect damage.

* 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.
Additional:
* Bristleback reduces most of Broodmother's and her spiderlings' damage.
* Quill Spray will hit any spiders in its proximity, hindering Broodmother's fighting and farming capabilities.

* Your AoE abilities should make quick work of her spiderlings.

* 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.
Additional:
* Quill Spray can be used to kill Lycan's summons.
* Bristleback allows him to stay alive against Lycan while dishing out counter attacks
* He can overpower Lycan with his Warpath instead.

* Heroes who summon multiple units that are not spell immune. Nature's Prophet,Lycan,Beastmaster

* Heroes that have AoE damage: Lina, Keeper of the Light, Timbersaw, Leshrac, Bristleback, Axe

* Heroes that have AoE damage: Lina, Keeper of the Light, Timbersaw, Leshrac, Bristleback, Axe

* Heroes who continue dealing damage while being stunned: Luna, Razor, Axe, Bristleback, Leshrac,

* Heroes who continue dealing damage while being stunned: Luna, Razor, Axe, Bristleback, Leshrac,

* Bristleback decreases Tiny's high burst damage against Bristleback.
* Tiny's high damage will also proc Bristleback multiple times.
* Viscous Nasal Goo can help counteract the bonus armor granted by Grow.

* Bristleback's abilities are nearly useless for Rubick to Spell Steal, as he does not gain the bonuses from Warpath.
Additional:
* Rubick deals little damage on his own, so Bristleback can simply shrug off all his spells and chase you down with his spells and attacks.
* Quill Spray requires multiple casts and close range to add up stacks. Because Rubick does not stay in the front lines, it's generally not a good spell for him to steal.
* Viscous Nasal Goo will slow Rubick down even further and reduce his armor, making him vulnerable to Quill Spray and the damage bonus from Warpath.

* 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.
Additional:
* Pudge is particularly susceptible to Bristleback's Viscous Nasal Goo and Quill Spray due to his naturally low armor & poor agility gain.
* Bristleback, in combination with his strength gain, high health, common itemization for magic resistance and damage reduction from Bristleback makes him a poor target for Pudge.

* Macropyre's frequent damage ticks causes Bristleback to activate repeatedly, resulting in free damage as long as Bristleback faces away from Jakiro.

* Quill Spray and Bristleback harass Luna more efficiently than she does with Lucent Beam.
* Bristleback withstands Luna’s nukes, and gives lots of damage in return.
* Viscous Nasal Goo and Warpath are enough to outrun a speedy Luna.
* Bristleback tends to be a frequent carrier of Crimson Guard, which is good protection from bouncing glaives.
Additional:
* 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 damage burst may be high, but it will not be enough for her to take down Bristleback.

* Viscous Nasal Goo slows down Dragon Knight and lowers armor, locking him down and making him more vulnerable.

* Leshrac's AoE abilities make quick work of Chen's creep army.

* Viscous Nasal Goo can hinder Crystal Maiden's already abysmal mobility, which allows Bristleback (or his teammates) to run her down and kill her.
* Bristleback frequently builds Blade Mail, which can quickly kill Crystal Maiden if her ultimate is used while he is under its effect.
* The passive part of Bristleback will trigger many, many times under the damage from Freezing Field, and as the stacks increase, the damage output from each successive cast (or proc) will eat away at Crystal Maiden's small HP pool.

* All of Leshrac's abilities, especially Pulse Nova can easily deal with Naga Siren's illusions.

* Quill Spray quickly destroys Chaos Knight's Phantasms.

* Diabolic Edict and Pulse Nova hit all units around Leshrac, making it very easy for him to kill the Summon Familiars.
* Diabolic Edict and Pulse Nova also deal many instances of damage, nullifying Gravekeeper's Cloak.
* Split Earth and Lightning Storm makes it difficult for Visage to kite Leshrac, even while under the effects of Grave Chill.

* Bristleback need not worry about charging into Magnetic Field, and quickly clearing up Arc Warden's summons and Tempest Double with Quill Spray.
Additional:
* Bristleback activates frequently while he escapes from Arc Warden's Necronomicon army.
* Arc Warden has little armor and mobility, which makes him an easy target to apply Quill Spray and Viscous Nasal Goo stacks.

* Quill Spray's constant AoE damage will hit Dark Willow even in Shadow Realm. Its automatic damage will hurt her if she tries to get close and use Bedlam.

* 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.

* Lone Druid and The Spirit Bear cannot burst down Bristleback due to Bristleback
* Bristleback can easily run to Lone Druid without any hesitation, with Viscous Nasal Goo to reduce armor and slow the Spirit Bear or Lone Druid and Quill Spray can deal damage to both Lone Druid and the Spirit Bear at the same time

* Bristleback's tankiness can enable him to chase Enigma out of a teamfight, making it difficult to initiate with a Black Hole.

* The bonus Backstab damage from Cloak and Dagger is rendered irrelevant with Bristleback and hurts Riki more than him because of the passive Quill Spray.
* Riki still gets damaged by Bristleback's Quill Spray while invisible, and it can be hard to deal with in lane.
* Bristleback is not too bothered by Smoke Screen. Though he cannot use Quill Spray manually inside it, it still procs passively when he takes damage from the back. The movement speed from Warpath allows him to get out of the area easily.
* Due to Bristleback's natural tankiness, he is an ideal Gem of True Sight carrier.
* Riki rarely buys Silver Edge to break Bristleback's passive because the invisibility aspect of it is redundant.
Additional:
* 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.

* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.

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

* Since Windranger is bad against magical damage, heroes with continuous magical damage or magical nukes can blast her: Zeus, Tinker, Leshrac, Viper, Skywrath Mage, Lion, Lina, Venomancer.

* Heroes that have disposable area-targeted spells can force her to undo her Meld: Leshrac, Puck, Tiny. An experienced Templar Assassin could try to Refraction before Meld so she can tank through those damage without getting her Blink disabled.

* 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

* Bristleback's Viscous Nasal Goo can catch and slow Bounty Hunter. Warpath and Quill Spray can defeat him quickly due to his small HP pool when compared to Bristleback's.

* Bristleback, Centaur Warrunner, Spirit Breaker, Pudge, Huskar: These heroes are too tanky for Puck to burst down. Also, all of them have spells which can deal with and shut Puck down reliably.

* Heroes that can punish aggressive heroes, such as: Leshrac, Shadow Demon, Pugna, Death Prophet.

* Heroes with wide AoE abilities will reveal Monkey King through Mischief: Necrophos, Phoenix, Alchemist, Earthshaker, Razor, Tinker, Leshrac, Queen of Pain

* Heroes who summon multiple units that are not spell immune. Nature's Prophet,Lycan,Beastmaster

* Diabolic Edict and Pulse Nova will tear apart any illusions spawned from Disruption
* Split Earth can punish improper usage of Disruption.
* Leshrac does not have any buffs that can be removed by Demonic Purge.
Additional:
* Pulse Nova makes quick work of any illusions with amplified damage, and deals damage even if Leshrac is in Disruption.
* An attempt to save an ally using Disruption can easily become a perfect setup for a Split Earth for the enemy.
* Disruption does not stop Diabolic Edict and Pulse Nova once they start pulsing, and even worse it provides a safe shelter for Leshrac to keep pumping up his powerful AoE damage onto the battlefield.
* Leshrac usually builds Eul's Scepter of Divinity to dispel Shadow Poison and Soul Catcher and Linken's Sphere to block Disruption and Demonic Purge.
* Shadow Demon doesn't have the burst damage to take Leshrac out of the fight quickly, although Demonic Purge can help his allies kill a squishy Leshrac.

* Bristleback's tankiness and Bristleback allow him to outlast Burning Spears' damage-over-time at almost any point in the game. In addition, if Huskar chooses to cast Life Break on Bristleback, Bristleback can simply turn around before it hits and receive little damage.
* Viscous Nasal Goo will reduce Huskar's low armor even further, and Quill Spray and Warpath will tear him down extremely quickly.
Additional:
* 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.

* Heroes who can slow and kite Axe will severely inhibit his presence in fights: Bristleback, Crystal Maiden, Batrider, Arc Warden, Winter Wyvern, Clockwerk

* Fortune's End cannot dispel Warpath stacks on Bristleback or Quill Spray stacks on allies.
* Bristleback can heavily reduce Oracle's damage output. With it, Oracle may accidentally heal Bristleback with Purifying Flames, especially if Bristleback has bonus magic resistance.