* The long silence at night prevents Clinkz from escaping with invisibility if Night Stalker can sneak up on him. He also has really low base health, so Night Stalker can usually kill him alone during one cast of Crippling Fear at night.

* Dark Ascension reduces vision for the enemy team, which makes it more difficult for Magnus to initiate with Blink Dagger and Reverse Polarity. It is also more likely that Night Stalker will scout out Magnus with Aghanim's Scepter and a Gem of True Sight, after which he can silence Magnus with Crippling Fear.

* Skeleton Walk is not enough to outrun Bloodseeker, and is detected by Thirst.
* Because of his low health and high damage output, Clinkz will get obliterated by Blade Mail
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.

* 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.

* Zeus can reveal Clinkz with Lightning Bolt.
* He is vulnerable to Zeus's magical nukes, due to his low health pool.

* Zeus can easily find Magnus who is often hiding in the trees with Thundergod's Wrath and Lightning Bolt, which allows him to warn allies and disrupt his initiation attempts.

* Clinkz will often roam the map alone, and Treant Protector's Nature's Guise allows him to set up kills with his allies on Clinkz from invisibility.
* Treant Protector's very high damage allowing him to trade hits or contest last hits with Clinkz, while Living Armor can be used to sustain the harass.
* Living Armor protects any of Treant's allies ganked by Clinkz.
* In teamfights, Treant Protector's Overgrowth can disarm Clinkz, preventing him from turning invisible and holding him in place even if he has a Black King Bar.
* Leech Seed slows Clinkz, preventing him from repositioning or fleeing away from danger.

* Treant Protector can usually scout out Magnus in the trees with Eyes in the Forest and disrupt his initiation attempts. He can also counter Magnus' initiation with Overgrowth.

* Heroes with high armor like Dragon Knight, or with abilities to cause attacks to miss like Phantom Assassin, Riki and Tinker will be hard to deal with, as Clinkz relies almost entirely on physical attacks.

* Tinker can break Magnus's Blink Dagger using March of the Machines and Heat-Seeking Missile, therefore delaying any initiation or making Magnus use Skewer or Force Staff to initiate. His {Ability ID:Defense Matrix|Tinker} will decrease the duration of Reverse Polarity and can also be cast on all of his teammates with {Ability ID:Rearm|Tinker}. Tinker usually gets his own Blink Dagger as well, which makes him harder to lock down unless Magnus commits Reverse Polarity only for Tinker.

* Untouchable prevents Clinkz from harassing Enchantress in lane by lowering his attack speed.
* Nature's Attendants helps Enchantress to sustain through Clinkz's harassment in lane.

* Heroes that have an escape that doesn't disjoint projectiles: Mirana, Faceless Void, Magnus

* Lina's damage burst can quickly kill Clinkz before he saves them with Skeleton Walk.
* Fiery Soul attack speed bonus removes Burning Army easily in all stages of the game.

* 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.

* Spectre can instantly escape Burning Army or hunt Clinkz with Haunt.
* Spectre can catch up to him with Spectral Dagger, even if he uses Skeleton Walk.
* Desolate allows Spectre to hit Clinkz through Skeleton Walk.
* Dispersion makes Spectre tanky and also reflects some damage back to Clinkz.
Additional:
* Spectre can catch Clinkz with Spectral Dagger, even if he uses Skeleton Walk.
* Spectre can instantly reach a ratting Clinkz with Haunt.
* Desolate's damage will melt him quickly, as he's alone most of the time.

* Spectre disables Magnus' Blink Dagger using her ultimate, and later into the game can usually outlive Reverse Polarity's duration.
Additional:
* Spectre can use Haunt to intercept and disrupt Magnus's initiation attempts.
* Spectral Dagger can severely slow down Magnus after he uses Skewer.
* Magnus often travels alone when he is trying to initiate, so Desolate can be very effective against him.
* In late game, Spectre can survive Reverse Polarity initiation thanks to Dispersion.

* Low-health, normally mobile carries who rely entirely on raw attack damage are vulnerable to Bane's nukes and disables: Anti-Mage, Clinkz, Drow Ranger, Faceless Void, Gyrocopter, Juggernaut, Meepo, Mirana, Monkey King, Morphling, Phantom Assassin, Phantom Lancer, Riki, Shadow Fiend, Slark, Sniper, Terrorblade, Troll Warlord, Weaver.

* Heroes that depend on disrupting fights with ability combos or big ultimate abilities are vulnerable to the long stun of Fiend's Grip: Disruptor, Death Prophet, Enigma, Faceless Void, Invoker, Lich, Magnus, Mars, Medusa, Outworld Destroyer, Phoenix, Puck, Queen of Pain, Shadow Fiend, Treant Protector, Underlord, Winter Wyvern, Witch Doctor, Zeus.

* 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.

* 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.

* Heroes with high armor like Dragon Knight, or with abilities to cause attacks to miss like Phantom Assassin, Riki and Tinker will be hard to deal with, as Clinkz relies almost entirely on physical attacks.

Additional:
* The extra damage from Searing Arrows is largely blocked by Dragon Knight's armor.
* Clinkz has too low health to survive a gank.Getting stunned keeps him down long enough for a reaction.
* Breathe Fire reduces his damage, as he almost exclusively deals physical damage.

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

* Heroes who rely on invisibility, such as Bounty Hunter, Clinkz, Mirana, Nyx Assassin and Riki, as they will be revealed if caught by Chronosphere.

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

* Sand King is a strong ganker, allowing him to shut down squishy heroes in the early game: Phantom Assassin, Clinkz, Sniper, Enchantress.

* 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.

* Heroes who cannot fight back during Arena of Blood in the early and mid game: Abaddon, Anti-Mage, Broodmother, Luna, Sniper, Troll Warlord, Weaver, Clinkz.

* 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.

* Even if Wraith King dies after Magnus disables him, Magnus' entire team will be slowed and vulnerable for counter-initiation.

* Cold Embrace can heal herself or an ally, as well as protecting them from Clinkz's physical attacks and wasting his mana if Searing Arrows is on autocast.
* Winter's Curse allows Winter Wyvern to turn Clinkz's high damage and high attack speed against his allies, or take advantage of Clinkz's fragility if he can't use Skeleton Walk.

* By using Morph, Morphling can use Burning Barrage and Searing Arrows to counter Clinkz himself.
* Waveform can allow Morphling to easily chase down Clinkz.
* Clinkz's low health pool also makes him vulnerable to Morphling's magical nukes, especially his Ethereal Blade and Adaptive Strike combo.

* Searing Arrows and Clinkz physical damage items are almost suicidal when used on Legion Commander, as it invites an instant Duel and Legion Commander herself is a natural Blade Mail carrier.
* Duel locks down Clinkz for a long duration, preventing him from escaping with Skeleton Walk.

* Slardar can reveal Clinkz with Corrosive Haze and make him easy to kill, and his Bash of the Deep also hits hard against Clinkz's naturally low health pool.
* Slardar's Guardian Sprint can catch up with Clinkz's Skeleton Walk.
* The stun and slow from Slardar's Slithereen Crush can hold Clinkz in place.
Additional:
* Clinkz survivability depends entirely on Skeleton Walk. Corrosive Haze not only makes its invisibility useless, but also makes Clinkz even more vulnerable to physical damage.

* Illusory Orb serves as a good scouting tool whenever Magnus is hiding in the trees, allowing Puck to warn its allies and disrupt his initiation attempts.
* Phase Shift allows Puck to dodge Shockwave when timed correctly.
* Even after Magnus successfully uses Reverse Polarity and Skewer Puck's teammates, Puck can usually counter-initiate using both Waning Rift and Dream Coil.
* Magnus cannot use Skewer when he is affected by Dream Coil, making him vulnerable to follow-up disables.
* Puck usually gets its own Blink Dagger as well, which makes it harder to lock down unless Magnus commits Reverse Polarity only for Puck.

* Clinkz has no stun and likes to keep his distance from targets, making Marksmanship very deadly.
* Clinkz also has low health, making him a perfect hero to initiate onto with Gust.
* Gust can also prevent Clinkz from using Burning Barrage.

* Possibly Clinkz's worst enemy. He has many tools to utterly destroy Clinkz.
* Charge of Darkness can be used on Clinkz if Spirit Breaker's team spots him anywhere. This charge will track his location through Skeleton Walk's invisibility and movement speed bonuses.
* When Spirit Breaker charges onto Clinkz, he can easily use Dust of Appearance to guarantee a reveal on him while stunned.
* All three of Spirit Breaker's spells help him and his team quickly close the gap to Clinkz even at the edge of his attack range or when running away with Skeleton Walk.
* Spirit Breaker's high strength and above average armor makes him able to endure Clinkz's onslaught, meanwhile Clinkz will be heavily threatened if Spirit Breaker procs a Greater Bash.
Additional:
* Once caught with dust, Clinkz could be locked down for a long time by Spirit Breaker and has nowhere to escape.
* Charge of Darkness provides shared vision over its target, showing Clinkz even when he is in Skeleton Walk.

* Hex and Earth Spike can hold Clinkz down, giving him no chance to use Black King Bar or Skeleton Walk.
* Finger of Death quickly kills Clinkz due to his low health.

* Jakiro's abilities deal damage over time, which can disrupt Magnus's attempts to initiate with Blink Dagger and Reverse Polarity.
* Macropyre not only disables Blink Dagger for a considerable duration, but can also destroy Trees, revealing Magnus's cover and position.

* Plasma Field can slow Magnus during Skewer, and when combined with Eye of the Storm, will potentially disable his Blink Dagger, preventing him from initiating.
* Static Link drains the bonus damage from Empower. However, it can be broken by Skewer and/or Force Staff.
* Storm Surge gives Razor and his allies high mobility needed to avoid Shockwave & Reverse Polarity.

* If Luna can use Eclipse in anticipation, Magnus will be killed before he can even manages to cast Reverse Polarity.
* Aghanim's Scepter upgraded Eclipse is a very good counter-initiation tool against Magnus when he casts Reverse Polarity, granted as long as Luna can cast it from safe distance.

* Scorched Earth deals damage to Clinkz during Skeleton Walk.
* Doom shuts down Clinkz entirely, as it prevents him from casting any of his spells and contributing a large amount of damage in teamfights.

* 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.

* 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.

* Fragile carries with no reliable escaping mechanism can be bursted down in no time: Sniper, Drow Ranger, Clinkz

* With Aghanim's Scepter, Broodmother will gain access to Spinner's Snare, which will allow her to create invisible lines on her webs from Spin Web that will root, deal damage over time, and reveal enemy heroes if they unwittingly step on them. This allows Broodmother to keep her allies alerted on heroes who rely on invisibility-themed and movement-themed abilities and items to surprise enemy heroes and disrupt ganking attempts of enemy heroes: Phantom Assassin, Nyx Assassin, Mirana, Bounty Hunter, Templar Assassin, Riki, Spirit Breaker, Anti-Mage, Tusk, Ursa, Nature's Prophet, Enigma, Void Spirit, Magnus etc.

* 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.

* 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.

* 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.

* Invisibility reliant heroes: Heroes with invisibility abilities or those that have invested into invisibility items are hindered by Bounty Hunter's Track. Few examples of such heroes are:Clinkz, Riki, Treant Protector, etc.

Additional:
* Track reveals Clinkz if he tries to escape with Skeleton Walk, allowing Bounty Hunter to gain lots of gold if he kills Clinkz.
* Jinada with physical damage items can quickly kill Clinkz due to his low health.

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

* 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.

* 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.

* Heroes that have high health but little to no magic resistance are easy prey for Necrophos, as no matter how high they build their health up, Reaper's Scythe will kill them outright as long as they fall under a certain threshold, and Heartstopper Aura will deal the same amount of damage regardless, decaying their health the longer they stay within range. As such, Strength heroes like Chaos Knight, Centaur Warrunner or Magnus are good targets for his ultimate.

* Heroes with blink or movement abilities, which are disabled by Pounce's leash: Anti-Mage, Earth Spirit, Faceless Void, Magnus, Mirana, Monkey King, Morphling, Pangolier, Phantom Assassin, Phoenix, Puck, Queen of Pain, Riki, Sand King, Spirit Breaker, Timbersaw, Tusk.

* Even though Linken's Sphere will block your silence, you can cast Arcane Bolt to break it or wait until someone on your team breaks it. In addition, Linken's Sphere builders are usually squishy targets vulnerable to silences: Weaver, Queen of Pain, Morphling, Clinkz, etc. Don't forget that Ancient Seal also increases the magical damage these enemies take, along with silencing them.

* Heroes who take a long time to become strong are in for a rough mid game, such as Outworld Destroyer, Magnus, Medusa, and Anti-Mage.

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

* In general, Brewmaster's Cinder Brew and Thunder Clap makes him good against physical damage carries: Ursa, Clinkz, Faceless Void, Troll Warlord, Templar Assassin, Phantom Assassin.

* Heroes with high armor like Dragon Knight, or with abilities to cause attacks to miss like Phantom Assassin, Riki and Tinker will be hard to deal with, as Clinkz relies almost entirely on physical attacks.

Additional:
* Smoke Cloud prevents the use of Death Pact, Searing Arrows and Skeleton Walk, so Clinkz can neither defend himself against Riki nor fight back effectively.
* It's hard to gank Riki as Clinkz has to find him first.

* 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.

* Disruptor can disable Magnus's Blink Dagger using Thunder Strike during a considerable duration, disrupting his initiation attempts.
* Glimpse brings Magnus back after he escapes with Skewer and/or Force Staff.
* Static Storm if used on a fight can prevent Magnus from using Reverse Polarity after he jumps in.

* Phoenix will usually be on the sidelines or further back ready to use Sun Ray. Even after Magnus successfully uses Reverse Polarity and skewer Phoenix's teammates, Phoenix can usually counter-initiate using all of its abilities.

* Magnus has very mediocre damage against Alchemist, because he can survive the stun duration of Reverse Polarity with Chemical Rage.

* Similar to Night Stalker, Venomancer can simultaneously scout Magnus hiding in trees and put Blink Dagger on cooldown with Plague Ward, which gives Magnus problems when trying to blink in and initiate.
Additional:
* Venomancer can simultaneously scout Magnus hiding in trees and putting Blink Dagger on cooldown with Plague Wards, which makes Magnus real problems to blink and initiate.

* Heroes who build mana boosting items but have low mana regeneration are especially vulnerable against Mana Break and Mana Void: Timbersaw, Slark, Shadow Fiend, Clinkz, Bristleback Nyx Assassin, Magnus

* Heroes who build mana boosting items but have low mana regeneration are especially vulnerable against Mana Break and Mana Void: Timbersaw, Slark, Shadow Fiend, Clinkz, Bristleback Nyx Assassin, Magnus

Additional:
* Anti-Mage can survive against Magnus's Reverse Polarity thanks to the high magic resistance from Counterspell.
* Should Anti-Mage survive Magnus's Reverse Polarity and Skewer, Magnus will have exhausted most of his skills and items, preventing him from defending himself against any counter initiation or a follow-up from a blink escape.
* Mana Break can deplete Magnus's much needed mana.
* Anti-Mage's Blink will make him a very hard target or Magnus to use Reverse Polarity on, having to solo ult him later on in the game or leave him out of the Reverse Polarity.
* Overall, any attempt for Magnus to gank Anti-Mage will hurt him more than it will hurt Anti-Mage.

* 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.

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

Additional:
* Most of Magnus's abilities except Empower will trigger damage through Corrosive Skin.
* Poison Attack and Viper Strike can slow Magnus during Skewer, as well as putting his Blink Dagger on cooldown, preventing him from initiating or re-initiating.

* 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.

* Shrapnel can sometimes scout out Magnus and also place his Blink Dagger on cooldown. Aside from that, Sniper likes to stay far back behind enemy lines, so it's difficult to catch him with Reverse Polarity unless you already have vision on him and can Skewer him to the rest of his team.

* Heroes with high armor like Dragon Knight, or with abilities to cause attacks to miss like Phantom Assassin, Riki and Tinker will be hard to deal with, as Clinkz relies almost entirely on physical attacks.

* 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.

* Heroes who rely on burst physical damage are affected by Lucky Shot's disarm: Terrorblade, Sven, Clinkz, Windranger, Alchemist, Dragon Knight, Legion Commander

* Heroes who rely on physical damage output to be effective will fare badly against Muerta's Pierce the Veil: Phantom Assassin, Terrorblade, Drow Ranger, Lifestealer, Anti-Mage, Alchemist, Lycan, Clinkz, Sniper.

* 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.

* Any hero who can survive Magnus's initiations and manfight him: Huskar, Faceless Void, Weaver, Abaddon, Troll Warlord, Alchemist, Dragon Knight, Night Stalker, Viper.

* All of Magnus's spells are perfect for Rubick to steal, especially Reverse Polarity for a counter-initiation.
* Telekinesis is one of the best instant-disables in the game, completely ruining Magnus's initiation.
Additional:
* Reverse Polarity, if stolen, can counter-initiate Magnus's team and put them at a huge disadvantage.
* Magnus himself is positioned at the center of teamfight after casting Reverse Polarity, and will be stunned by Rubick's stolen one most of the times.
* Bear in mind that Magnus will usually cass Skewer or Shockwave after he casts the ultimate, so the time windows left for steal can be short.
* Shockwave allows Rubick to farm fast, and also deals decent AoE damage in teamfights.
* Empower can be casted on the carry (especially affective if melee) on Rubick's team to accelerate their farm or amplify their damage in fights.
* Skewer could be used to displace enemy or escape from danger.
* Telekinesis can relocate the enemy in front of Rubick for Skewer.
* With Quick Cast enabled, Rubick can stop the enemy Magnus with careful prediction using Telekinesis to interrupt Horn Toss - Skewer combo.

* Frostbite will reveal invisible heroes for its duration, making it a good tool against any such hero (Riki, Bounty Hunter, Weaver, or Clinkz for example), or as a soft counter to Shadow Blade, if it is used first. This can be an amazing tool to ensure that Dust of Appearance is used on the unit in question, and not wasted in not catching anything.

* 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.

* 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.

* Magnus cannot manfight Huskar even with Empower, Berserker's Blood's high attack speed and health regeneration, combined with Huskar's high health and Burning Spear stacks will allow Huskar to kill Magnus before he can kill him.
* From a safe distance, Huskar can surprise and counter Magnus's initiation with Life Break and Burning Spear.
* Burning Spear also deals damage over time, disabling Blink Dagger and preventing him from initiating or escaping.

* 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.