* Enemies that possess high defenses through magic resistance, damage reduction, or high regeneration will make it difficult to whittle their health down to get to Reaper's Scythe's threshold. Such heroes include Bristleback (although only from behind), Spectre, Ursa, and Dragon Knight.

* Heroes who can stop Axe from getting close will severely inhibit his presence in fights: Bristleback, Crystal Maiden, Batrider, Arc Warden, Winter Wyvern, Clockwerk

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

* Heroes who cannot prevent Sven from killing supports will always be at a disadvantage in fights such as Lina, Slark and Zeus.

* Sven's Great Cleave can clear Anti-Mage's illusions from Manta Style and his high health pool and low mana, making Mana Void very ineffective, although keep in mind that Storm Hammer is extremely easy to reflect with a well-timed Counterspell.

Additional:
* Anti-Mage is fairly fragile, and cannot stand against Sven in a prolonged fight.
* Sven's Black King Bar and low base mana can protect Sven from the effects of Mana Break and Mana Void.
* Great Cleave destroys the illusions from Anti-Mage's Manta Style.
* Although Sven should be careful as a well-timed Counterspell can block and reflect Storm Hammer back at Sven.

* Great Cleave and God's Strength destroys illusions in just a few hits.
* Storm Hammer's AoE stun will hit Phantom Lancer when he's grouped up with illusions.
* Sven's low mana causes him to take less damage from Diffusal Blade. This is further reduced by the armor bonus from Warcry.
Additional:
* Great Cleave and God's Strength cuts through Phantom Lancer's illusions in no time.
* Storm Hammer's AoE stun will hit Phantom Lancer and his illusions.

* 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 quickly 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:
* 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.

* Storm Hammer's faster projectile speed and cast time allows Sven to stun Chaos Knight and his illusions before he can cast Chaos Bolt.
* Warcry's armor bonus counteracts Reality Rift's debuff and reduces Chaos Knight's damage output.
* Great Cleave and God's Strength devastates Phantasm illusions.
Additional:
* Great Cleave is very effective against Chaos Knight's illusions.
* Storm Hammer's radius can catch all of Chaos Knight's illusions at once, especially after Reality Rift.
* Warcry shields Sven and his teammates against Chaos Knight's physical damage output.

* Quill Spray quickly destroys Chaos Knight's Phantasms.

* Avalanche and Toss will never be enough damage to take out Sven in a clean way.
* Tiny is very slow with low armour growth and does not buy items to sustain Sven's damage output.

* Tiny's nonexistent armor in the early game makes him very vulnerable to Quill Spray's large amounts of physical damage.
* Bristleback decreases Tiny's high burst damage against Bristleback.
* Viscous Nasal Goo can slow Tiny to a crawl and allows Bristleback to easily kite him with his high movement speed and Quill Spray's long range, as Tiny has no ability to escape.

* Great Cleave will kill Lycan's summons very rapidly.
* Warcry will allow Sven and his allies to tank Lycan's damage, which is mainly physical.
* Storm Hammer will damage and stun Lycan's as well as his summons.

* 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.

* Great Cleave and God's Strength can take down Meepo and his clones very quickly.
* The lack of spell immunity for Meepo's clones makes them vulnerable to Storm Hammer.
Additional:
* Great Cleave will devastate Meepo's clones. Against a closely packed group, Sven does not even need to target the clone with the lowest health.

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

* Great Cleave cleans up Spiderlings quicker than most spells, as it ignores their magic resistance.
* Sven is a natural Black King Bar carrier, protecting him from Silken Bola, Spawn Spiderlings and Orchid Malevolence.
* Warcry and God's Strength allow Sven to easily out-damage Broodmother.
Additional:
* Great Cleave can clear Spiderlings very quickly, and give Sven lot of gold.
* Warcry shields Sven and his allies against Broodmother and her Spiderlings.

* 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.

* Fragile supports who die in a few hits against Sven's high physical damage: Crystal Maiden, Vengeful Spirit, Dark Willow.

* 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.

* Generally heroes who don't rely on magical damage, such as Sven, Phantom Assassin, and Outworld Destroyer, as they can practically ignore Flesh Heap's damage block.

* 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 and 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.

* Heroes with high burst damage and Black King Bar can take down Dark Willow quickly: Phantom Assassin, Sven, Wraith King

* 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.

* Melee carries who usually buy an early Black King Bar, and have gap closing abilities can be good against the Arc Warden, such as Slark, Riki, Earthshaker with Aghanim's Scepter, Sven with Aghanim's Scepter etc.

* Arc Warden has relatively lower armor and mobility, which makes him an easy target to apply Quill Spray and Viscous Nasal Goo stacks.
* Arc Warden also does not like to build a Silver Edge as it takes a long time to build up and may slow down the timings for other important items needed in the game like Gleipnir.
* However, do note that in a game where Arc Warden's team has many jumping capabilities or good passives, like a Tidehunter or Spectre, a Silver Edge becomes incredibly valuable on Arc Warden as not only can he run away from the jumps, he effectively gets 2 breaks, and Bristleback may not be the best pick.

* Sven with Aghanim's Scepter-upgraded Storm Hammer can easily chase down Windranger and dispel her Windrun at the same time.

* Combo Quill Spray and items Blade Mail can easily trigger from Focus Fire damage.
Additional:
* Using Focus Fire on Bristleback tends to fare badly for Windranger, as he can trigger passive Quill Sprays many times, especially when she attacks him from behind. In addition, Windrun does not protect her from both Viscous Nasal Goo and Quill Spray, rendering her helpless.
* Bristleback's natural tankiness makes it hard for Windranger to effectively burst her down throughout the game.
* Bristleback tends to continuously spam Viscous Nasal Goo to slow down Windranger when she uses Windrun to escape, potentially allowing him to outrun her with his Warpath stacks.
* Bristleback can build Lotus Orb to reflect Shackleshot and Focus Fire back at Windranger.

* A couple of nukers and disablers on the same lane can finish a squishy Luna efficiently despite a teammate's assistance: Sven + Shadow Shaman.

* Heroes with damage-over-time abilities easily allow Bristleback to turn his back in order to proc Bristleback continuously and to massively reduce to damage dealt to him: Arc Warden, Venomancer, Luna.

Additional:
* Quill Spray and Bristleback harass Luna more efficiently than she does with Lucent Beam.
* Bristleback helps return a lot of damage to Luna’s team if she uses her nukes on him and he has his back to her.
* Viscous Nasal Goo and Warpath are enough to outrun a speedy Luna.
* Bristleback tends to be a frequent carrier of Crimson Guard and Eternal Shroud, which are good protection from Moon Glaives and Eclipse.
* For the same reasons, Bristleback makes a very powerful ally for Luna when they are in the same team.

* Storm Hammer locks down Chen and his converted creeps.
* Great Cleave and God's Strength can destroy Chen and his creeps quickly.
* Warcry minimizes damage taken from creeps's attacks.
Additional:
* Great Cleave can quickly destroy Chen's creeps in team fights, before they have a chance to do much.

* Storm Hammer stunned can stops Snapfire's Mortimer Kisses.

* 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, and Bristleback can simply shrug off all his spells and chase Rubick down with his Quill Spray and the damage bonus from Warpath.
* Rubick does not tend to charge forward in teamfights, stay in the front lines under most circumstances, yet effective casts of Quill Spray and Viscous Nasal Goo requires the opposite as they require multiple casts and close range to add up stacks.
* Rubick does not benefit from Warpath through casting the stolen spell.

* God's Strength allows Sven to take down Death Prophet quickly, reducing the damage dealt over time from Exorcism.
* Warcry's bonus armor and movement speed is very useful for Sven and his teammates against Exorcism, which deals physical damage.

* 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.

* With God's Strength, Warlock's Golem from Chaotic Offering will go down in a matter of seconds. The two weaker golems granted by Aghanim's Scepter will fare worse due to Great Cleave hitting both.
* Aghanim's Scepter upgraded Storm Hammer Aghanim's Scepter can dispel Shadow Word.
Additional:
* God's Strength combined with Great Cleave destroys Chaotic Offering golems within seconds.
* Warcry gives Sven and his allies armor to help against Warlock's Golem's heavy physical damage and movement speed to help escape Upheaval.
* Storm Hammer disrupts Upheaval.

* Sven has a high health pool and is a natural Black King Bar holder and is very hard to kill for Lina.
* Sven also has high physical damage, making it easy for him to burst her down.

* 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.

* Bristleback's constant harass from Quill Spray will greatly hurt Enigma's laning and kill his Eidolons.
* However, Bristleback has no way of canceling Black Hole at all. And Bristleback is not a hero that goes for disabling items to counter that problem.

* Warcry makes it difficult to burst Sven down with both the passive (with Aghanim's Shard) and active component.
* Sven under the effect of God's Strength and his massive physical damage make Sven very dangerous to engage in the mid game.

* Storm Hammer interrupts Echo Stomp.

* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.

* Heroes with cleave damage: Sven, Magnus, Kunkka.

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

* Heroes who cannot prevent Sven from killing supports will always be at a disadvantage in fights such as Lina, Slark and Zeus.

* Late game heroes are Sven's favourite kind of opponent, such as Anti-Mage, Spectre and Shadow Fiend.

* Heroes who cannot prevent Sven from killing towers will often struggle from a small map very early, such as Phantom Assassin, Storm Spirit and Phantom Lancer.

* Late game heroes are Sven's favourite kind of opponent, such as Anti-Mage, Spectre and Shadow Fiend.

* Heroes with high armor and/or durability can handle Juggernaut's ultimate, such as Sven and Dragon Knight.

Additional:
* Warcry allows Sven to tank the damage from Omnislash due to its high armor gain.
* However Blade Fury provides spell immunity which blocks the stun from Storm Hammer.

* Side lanes with disables will greatly reduce the likeliness Void Spirit will be willing to rotate: Sven, Tiny, Wraith King, Ogre Magi.

* Heroes who cannot prevent Sven from killing towers will often struggle from a small map very early, such as Phantom Assassin, Storm Spirit and Phantom Lancer.

* Heroes who struggle to fight back against Sven at any point in the game are at a severe disadvantage: Alchemist, Anti-Mage, Crystal Maiden.

* Strong laners are usually at a disadvantage because of how well Sven can jungle. Heroes such as Dark Seer. Underlord and Legion Commander may find that later Sven takes care of them very quickly after some jungle farming.

* Heroes with high physical damage can damage Lifestealer more than he can heal: Bristleback, Clinkz, Luna,Shadow Fiend, Slardar, Terrorblade

* Great Cleave with God's Strength clears Terrorblade's illusions quickly.
* Storm Hammer's AoE stuns Terrorblade and his illusions.
* Warcry gives Sven and his allies armor to withstand Terrorblade's only-physical damage output.

* Warcry can protect Sven and his teammates from Swashbuckle.
* With Black King Bar, Sven will be able to protect himself from most of Pangolier's skills.

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

* Past the early game, Sniper is an easy target for Sven to jump on with Aghanim's Scepter upgraded Storm Hammer, Blink Dagger, Silver Edge or Harpoon, common items on Sven.
* Sven's high armor and health pool makes it difficult for Sniper to focus, as his main source of damage is his right click, especially if Sven uses Warcry.
* Sniper is very squishy, and will not stand a chance against Sven head on.

* 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.
Additional:
* 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.

* 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

* 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.

* Doom generally does not impede Sven in almost any way, provided he has activated God's Strength beforehand.

* Heroes with damage-over-time abilities easily allow Bristleback to turn his back in order to proc Bristleback continuously and to massively reduce to damage dealt to him: Arc Warden, Venomancer, Luna.

* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: Sven, Omniknight, Enigma, Luna, Naga Siren, Mars, Jakiro, Venomancer, Elder Titan, Faceless Void, Rubick, Keeper of the Light, Pugna, Invoker, Spectre, Alchemist, Treant Protector, Lina, Oracle, Zeus, Shadow Shaman, Phoenix, Razor, Huskar, Batrider, Kunkka, Tidehunter, Wraith King, Sand King, Medusa, Dawnbreaker.

* Axe, Bristleback, Centaur Warrunner, Spirit Breaker, Pudge, Huskar, Wraith King, Doom: 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.

* 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.
Additional:
* 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 can still get 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.

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

* Heroes who can continue dealing damage even while being stunned: Luna, Razor, Axe, Bristleback, Leshrac, Death Prophet, Jakiro.

* 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.

* God's Strength makes Sven one of the worst heroes to Duel.
* Storm Hammer can be used to interrupt Duels.
* Warcry gives a big boost in passive defensive ability with the active component to nearby allies.
* With the Aghanim Shard Warcry also gives nearby allies passive increases.

* Fragile supports who die in a few hits against Sven's high physical damage: Crystal Maiden, Vengeful Spirit, Dark Willow.

* Strong laners are usually at a disadvantage because of how well Sven can jungle. Heroes such as Dark Seer. Underlord and Legion Commander may find that later Sven takes care of them very quickly after some jungle farming.

* Although Sven relies often on physical damage, an Aghanim's Scepter upgraded Storm Hammer can dispel Guardian Angel with its wide radius.