* With Aghanim's Scepter upgraded Infest, Lifestealer can use it on enemy heroes to attack them and disarm them from inside, even if they are spell immune, which can give him the edge over the heroes he's weak against like Ursa, Phantom Assassin, Terrorblade or Troll Warlord.

* With Aghanim's Scepter upgraded Infest, Lifestealer can use it on enemy heroes to attack them and disarm them from inside, even if they are spell immune, which can give him the edge over the heroes he's weak against like Ursa, Phantom Assassin, Terrorblade or Troll Warlord.

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

* Heroes with built-in spell immunity can become immune to all of Outworld Destroyer's spells: Lifestealer's Rage and Juggernaut's Blade Fury.

* With Aghanim's Scepter upgraded Infest, Lifestealer can use it on enemy heroes to attack them and disarm them from inside, even if they are spell immune, which can give him the edge over the heroes he's weak against like Ursa, Phantom Assassin, Terrorblade or Troll Warlord.

* 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.

* 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.

* Feast will deal a enormous amount of damage because of Tiny's huge health pool.
* Rage protects Lifestealer from Tiny's magical burst damage.

* 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.

* Rage renders Lifestealer immune to the damage from Burning Spears.
* Feast makes Lifestealer one of few heroes that can outlast Huskar in a one-on-one fight.

* 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.

* The lifesteal of Feast scales accordingly to the max health of its target, which is effective against Pudge due to his high health and further health granted by stacks of Flesh Heap.
* Lifestealer can activate Rage to be spell immune, making Rot deal no damage.
* Pudge's plentiful health makes him an ideal target for Lifestealer's Aghanim's Shard ability, Open Wounds.

* 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.

* Rage protects and dispels all of Dark Willow's abilities.
Additional:
* Rage protects Lifestealer from all of Dark Willow's abilities.

* 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.

* Juggernaut and Lifestealer have abilities (Blade Fury and Rage respectively) that prevent Crystal Maiden from using her spells on them in the early game, before Black King Bar and other magical reduction is even an issue.

Additional:
* Crystal Maiden is an ideal target for Lifestealer due to her poor mobility and low health pool. Lifestealer can usually catch up to her simply by casting Rage, as none of her abilities pierce through magic immunity. Freezing Field can potentially make her even more vulnerable to Lifestealer while under Rage as she is even more immobile while channeling it.
* Lifestealer commonly buys Abyssal Blade, which allows him to cancel Freezing Field, even if Crystal Maiden is spell immune.
* Alternatively, Aghanim's Scepter upgraded Infest combined with Abyssal Blade and with items that provide attack speed which Lifestealer commonly buys allow him to to cancel Freezing Field from within the Crystal Maiden.

* 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.

* Heroes that can easily bypass Io's allies to get to Io: Riki, Tusk, Clinkz, Sniper, Slark, Phantom Assassin, Void Spirit, Storm Spirit, Ember Spirit, Earth Spirit, Spirit Breaker, Lifestealer.

* 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.

* Heroes with good escape mechanisms are a nuisance to deal with in the early phase of the game: Slark, Lifestealer, Morphling

* 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.

* Lifestealer with Rage and Infest
* Heroes that can remove the Track debuff with their skills:
* Abaddon with Aphotic Shield and Borrowed Time
* Huskar with Life Break
* Juggernaut with Blade Fury
* Legion Commander with Press the Attack
* Lifestealer with Rage and Infest
* Naga Siren with Mirror Image
* Omniknight with Heavenly Grace
* Oracle with Fortune's End and False Promise
* Phantom Lancer with Doppelganger
* Slark with Dark Pact
* Ursa with Enrage
* Weaver with Time Lapse
* Tidehunter with Kraken Shell when damage received reaches the threshold.

* 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.

* Rage gives Lifestealer spell immunity, Chen and his converted creeps have little to no ways of fighting back against Lifestealer whenever he activates it.
* Feast allows Lifestealer to recover himself by damaging Chen's creeps.
* Chen has no escape mechanisms, so he will often be unable to escape from slows applied with Ghoul Frenzy.
* Open Wounds from Aghanim's Shard can severely slow down Chen, and allow Lifestealer and his team to heal themselves by attacking Chen. Open Wounds can also fester and spread if Chen takes enough damage that will trigger the spread while he is affected with Open Wounds.
* Infest allows Lifestealer to infest into one of Chen's converted creeps and take control of it, which allows Lifestealer to either escape from Chen or surprise him. Aghanim's Scepter upgraded Infest can disarm Chen and allow Lifestealer to attack Chen from within, even if Chen is spell immune.

* Rage protects Lifestealer from all of Techies's abilities. Reactive Tazer's disarm will also not work on Lifestealer under Rage.
* Rage can also be used to trigger Techies's Proximity Mines safely.
Additional:
* Lifestealer's Rage lets him clear Proximity Mines without taking damage, and allows him to hit heroes whom Techies has used Reactive Tazer on.

* Rage, acting as a pseudo-Black King Bar, completely negates Mars' initiation if used in time.
* Feast does damage and heals based on max health, perfect against high-health strength heroes like Mars.
* Infest allows Lifestealer to potentially save allies from Mars' initiation with a quick burst of extra health.

* Rage grants immunity from Invoker's spells and can dispel most of the disables such as the armor loss from Forge Spirit and the constant stuns of Cold Snap.
Additional:
* Rage protects Lifestealer from all of Invoker's spells (except for Sun Strike).

* Rage ignores all of Gyrocopter's magical attacks.
* Feast helps Lifestealer out-damage Gyrocopter at close range.

* Lifestealer can close the distance to Sniper by using Infest on a fast or durable creep to tank Sniper's damage.
* Open Wounds and Ghoul Frenzy will reduce Sniper's mobility heavily, and Rage's movement speed bonus helps in closing the gap to Sniper. It also protects him from Assassinate and Shrapnel.
* Infest can dodge an incoming Assassinate or to surprise Sniper during ganks. Aghanim's Scepter upgraded Infest can also allow Lifestealer to disarm Sniper and attack him from inside.

* Feast deals damage and heals lifestealer based on the target max health. Because Spectre often emphasises on building stat items to increase her HP pool, lifestealer can deal a lot of damage to her and heal himself at the same time.
* Ghoul Frenzy slows target, which is bad for Spectre if she does not have Spectral Dagger ready.
* Spectre cannot response to infest if lifestealer choose to stay inside his high mobility allies to approach the backline. Rage's bonus movement speed and spell immunity make it even more frustrating.

* Rage allows him to be immune to all of Ezalor's abilities. Also, the increased movement speed combined with the slow from Ghoul Frenzy and the squishy nature of Ezalor allows Lifestealer to take him down very quickly.

* 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.

* Being a strength hero with a high strength gain means Feast can give her a hard time,especially later in the game.
* However,Starbreaker's physical damage can control him in the laning phase.

* Rage grants Lifestealer immunity to all of Jakiro's spells. Note: magic resistance will not dispel the attack speed slow effects from Dual Breath and Liquid Fire.

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

* Rage allows Lifestealer to freely attack Nyx Assassin and hunt him down if Vendetta is on cooldown. Nyx Assassin cannot counter Rage with Spiked Carapace because Rage gives Lifestealer spell immunity. And besides Vendetta, Nyx Assassin has no other way of dealing damage to Lifestealer while he is spell immune.
* Open Wounds from Aghanim's Shard allows Lifestealer to severely slow down Nyx Assassin while also allowing his team to recover themselves while attacking Nyx Assassin. Open Wounds can also fester and spread if Nyx Assassin takes enough damage that will trigger the spread while he is affected with Open Wounds.
* Infest combined with an ancient creep makes Nyx Assassin an easy target to surprise with Dust of Appearance or a Gem of True Sight. Aghanim's Scepter upgraded Infest can also allow Lifestealer to infest, disarm and freely attack Nyx Assassin from within. and Nyx Assassin cannot counter this with Spiked Carapace because Lifestealer is invulnerable while attacking the infested enemy hero from within.
* Overall, any attempt for Nyx Assassin to gank and kill Lifestealer will hurt Nyx Assassin more than Lifestealer.
Additional:
* Like with Juggernaut's Blade Fury, Rage allows Lifestealer to freely attack Nyx Assassin and hunt him down if Vendetta is on cooldown. Nyx Assassin cannot counter Rage with Spiked Carapace because Rage gives Lifestealer spell immunity. And besides Vendetta, Nyx Assassin has no other way of dealing damage to Lifestealer while he is spell immune.
* Open Wounds from Aghanim's Shard allows Lifestealer to severely slow down Nyx Assassin while also allowing his team to recover themselves while attacking Nyx Assassin. Open Wounds can also fester and spread if Nyx Assassin takes enough damage that will trigger the spread while he is affected with Open Wounds.
* Infest combined with an ancient creep makes Nyx Assassin an easy target to surprise with Dust of Appearance or a Gem of True Sight. And similarly to Juggernaut's Omnislash and Swiftslash from Aghanim's Scepter, Aghanim's Scepter upgraded Infest can also allow Lifestealer to infest, disarm and freely attack Nyx Assassin from within. And Nyx Assassin cannot counter this with Spiked Carapace because Lifestealer is invulnerable while attacking the infested enemy hero from within.
* Like with Juggernaut, any attempt for Nyx Assassin to gank and kill Lifestealer will hurt Nyx Assassin more than Lifestealer.

* Rage can be used to escape from a Glimpse and to move out of Kinetic Field.
* Infest allows Lifestealer to dodge Glimpse.

* Leshrac's high magic damage is ignored by Rage.
* Lifestealer can get in Leshrac's face with Rage and mitigate any other damage taken by Leshrac with Open Wounds.

* Feast is good against high health strength heroes such as Alchemist.
* Rage allows Lifestealer to not be targetable by Unstable Concoction, possibly making Alchemist stun himself.

* Lifestealer's Rage makes him immune to all of Ogre's magical debuffs and also dispels them.
* Ogre's high health pool makes him an ideal target for Feast.
Additional:
* Ogre Magi has nothing against Rage and his high health pool amplifies Feast.

* Rage negates Kunkka's X Marks the Spot.
* As a strength hero with high strength gain and very little armor, as well as low agility gain, Kunkka is vulnerable to Lifestealer's Feast and Open Wounds.

* Rage prevents Earthshaker from damaging and stunning Lifestealer.
* Feast is very effective against Earthshaker, because of him being a strength hero, allowing Lifestealer to heavily harass and kill him.
* Open Wounds prevents Earthshaker from escaping after he initiated.
* Infest gives Lifestealer an easy way to escape should he get caught out by Earthshaker. And against carry Earthshaker, Aghanim's Scepter upgraded Infest can be used to disarm Earthshaker and attack him from within, rendering him unable to attack with Enchant Totem.

* Lifestealer is not affected by Earthbind or Poof during Rage, making him a difficult target to work around.

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

* Lifestealer's Rage renders him immune to all of Marci's disables and magic damage for a good duration.
* His passive Feast deals bonus damage based on the enemy's max health and heals for the same amount. As a tanky Strength hero, Marci's own strength will be her undoing as well.

* With Feast and Rage, Lifestealer is nearly impossible for Clockwerk to bring down, and is the last hero Clockwerk wants to be trapped with in Power Cogs.

* Feast is an effective tool against Centaur Warrunner, who generally has high health and low armor, and compensates the reflected damage of Retaliate.
* If activated, Rage can protect Lifestealer from Hoof Stomp, Double Edge, and Stampede.
Additional:
* Centaur Warrunner's active abilities cannot pierce magic immunity. Hoof Stomp's slow wind up can also be anticipated and negated with Rage.
* Lifestealer can offset Retaliate's damage return simply with Feast. Centaur's high strength gain and therefore big health pool makes him an ideal target to Feast on, especially in the late-game.

* Lifestealer's Rage negates Sand King's spells which do magical damage.

* 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

* Feast makes it impossible to for Lifestealer to be culled with Culling Blade and also deals high damage to Axe due to his naturally high health.
* However, Berserker's Call and Counter Helix can pierce through the Rage, and if Axe has allies with him against Lifestealer, Lifestealer may go down very quickly.

* Heroes who can stop Axe from getting close 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.

* Lifestealer's Rage makes him immune to all of Tinker's damage and debuffs.
* Lifestealer can infest a mobile ally (teams usually pick one against Tinker), which may ensure that Tinker will die if he is caught.
Additional:
* Rage will dispel Laser's blind and turns him spell immune for the duration so Tinker cannot damage him.
* Feast will quickly bring down Tinker due to being so fragile.

* 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.

* Heroes with spell immunity or pseudo-blinks which provide invulnerability: Lifestealer, Juggernaut, Omniknight, Huskar, and Tusk have spells which allow them to easily escape Dream Coil.

* 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.

* Heroes who have most or all their abilities (damage or disable) unable to pierce spell immunity: Keeper of the Light, Lina, Lion, Zeus.

Additional:
* Rage is very useful against Zeus, as it negates magic damage and provides spell immunity. In addition, the increased attack speed can tear Zeus apart in combination with Open Wounds.
* Lifestealer can avoid Thundergod's Wrath with Infest.

* Heroes with burst damage of their own won't be afraid to go toe to toe with Void Spirit, like Ursa, Lifestealer, or Axe.

* Heroes who have most or all their abilities (damage or disable) unable to pierce spell immunity: Keeper of the Light, Lina, Lion, Zeus.

Additional:
* Rage protects Lifestealer from all of Lina's abilities. However, Lina can paritally counter this if played as Carry, a common role for Lina.
* Open Wounds from Aghanim's Shard can severely slow down Lina and allow Lifestealer and his allies to recover themselves by attacking her.
* Aghanim's Scepter upgraded Infest can be used to disarm Lina even if she is spell immune, rendering her unable to maximize the effect of her Fiery Soul and force her to use her abilities more often than intended. And Lina's only way to counter this is with Linken's Sphere

* Enigma lacks burst damage, and that makes him vulnerable to heroes who can recover themselves and turn the fight around to their advantage after Enigma finishes his initiation: Faceless Void, Terrorblade, Ursa, Weaver, Broodmother, Slark, Abaddon, Wraith King, Lifestealer.

* 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.

* Heroes with spell immunity abilities won't be caught inside by Pit of Malice: Juggernaut, Lifestealer.

* Lifestealer can activate Rage to become spell immune, making Pierce the Veil do no damage and preventing Dead Shot from fearing or doing damage.
* Lifestealer can use Infest to avoid Muerta's Gunslinger shots, Dead Shot's fear and surprise Muerta. Aghanim's Scepter upgraded Infest can be used to disarm Muerta while she has Pierce the Veil and even through Black King Bar.
* However, Lifestealer has no way of hurting Muerta through Pierce the Veil outside of Infest, Lifestealer's only source of dealing magical damage. This forces Lifestealer to buy Revenant's Brooch.

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

* 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.

* 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.

* 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.

* Feast deals damage and heals Lifestealer based on the target's maximum HP, which is greatly effective against naturally high HP heroes such as Doom.
* Rage allows Lifestealer to become spell immune to negate the magical damage of Infernal Blade and Scorched Earth.
* Doom has no effective means of escape from Open Wounds and Ghoul Frenzy. This is particularly devastating in the laning stage, where Doom may have to play a much more passive, conservative play style as a result.

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

* Quill Spray quickly destroys Chaos Knight's Phantasms.

* Heroes who have most or all their abilities (damage or disable) unable to pierce spell immunity: Keeper of the Light, Lina, Lion, Zeus.

Additional:
* Rage makes Lifestealer debuff immune and gives him magic resistance which can drastically reduce magical damage from Lion's abilities while also preventing Lion to do anything to him.
* Lion's lack of inner escape and defensive mechanisms increases Ghoul Frenzy effectiveness, since it applies slows upon attacking.
* Lifestealer's physical damage output is strong against Lion's low health and base armor
* Infest can be used to surprise unsuspecting Lion if he tries to take down alone enemy hero. Aghanim's Scepter upgraded Infest can be used to disarm Lion and attack him from inside, even if Lion is debuff immune with the Aghanim's Shard upgraded Mana Drain.

* 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.

* Rage can protect Lifestealer from most of the Silencer's abilities with the exception of Global Silence, as it will still silence if cast while the target is magic immune. However, it will not work if Lifestealer is infesting a unit.
* Silencer is vulnerable to Open Wounds due to his lack of an innate escape.
* Against a carry Silencer, Aghanim's Scepter upgraded Infest can disarm him and allow Lifestealer to attack Silencer from within, even if Silencer is spell immune.
Additional:
* Rage can protect Lifestealer from most of the Silencer's abilities with the exception of Global Silence.
* If Lifestealer can Infest himself on any unit, he can literally avoid being affected by Global Silence.
* Against a carry Silencer, Aghanim's Scepter upgraded Infest can disarm him and allow Lifestealer to attack Silencer from within, even if Silencer is spell immune.
* Open Wounds from Aghanim's Shard can severely slow down Silencer, and allow Lifestealer and his team to heal themselves by attacking Silencer.

* Heroes with spell immunity-granting spells will render Phoenix useless against them, as Phoenix has almost no spell immunity-piercing ability, other than the stun at the end of Supernova: Lifestealer, Juggernaut.

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

* 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.

* With Aghanim's Scepter upgraded Infest, Lifestealer can use it on enemy heroes to attack them and disarm them from inside, even if they are spell immune, which can give him the edge over the heroes he's weak against like Ursa, Phantom Assassin, Terrorblade or Troll Warlord.

* Rage ignores all of Viper's magical damage, although Viper Strike can pierce spell immunity and slows him down.
* Feast and Open Wounds from Aghanim's Shard can be combined to heal through Viper's physical damage.
* Aghanim's Scepter upgraded Infest can be used to disarm Viper, preventing him from using Poison Attack on Lifestealer's allies.

* Lifestealer is able to endure Undying, especially in the laning phase, where Undying is strongest. Feast can offset Decay's strength steal for its percentage lifesteal. Rage delays Undying from stealing strength and can help Lifestealer destroy Undying's Tombstone uninterrupted. As well, none of Undying's abilities pierce magic immunity.

* Heroes with magic immune abilities can negate most of Visage's attacks like Pangolier and Lifestealer.