* Arc Warden relies on items and abilities, as well as his {U:Tempest Double}, to deal damage to enemies. Doom effectively denies that and makes Arc Warden useless in fights.

* Doom has several disable abilities to choose from jungle creeps (e.g. War Stomp, Ensnare) to deal with Shadow Fiend who lacks escape abilities.
* When Doom combines creep abilities with Scorched Earth, Infernal Blade, and Doom, Shadow Fiend most likely will die as he cannot use Shadowraze and Requiem of Souls to protect himself, and also cannot even flee by using Shadow Blade or Blink Dagger.
* Although Shadow Fiend has a high physical damage output, Doom has a large health pool to survive it, meaning Doom's combo with high magical damage output will shutdown Shadow Fiend first.
* Doom usually buys Radiance to improve his damage, making his nuke combo more deadly to Shadow Fiend. The blind also prevents Shadow Fiend from landing his attacks often.

* Smoke Screen prevents Arc Warden from initiating or helping his team, as he struggles to escape the silence with low mobility.
* With Arc Warden's low mobility, Tricks of the Trade is wide enough to deal decent damage to him.

* Heroes that can gank Shadow Fiend in the early game: Earth Spirit, Nyx Assassin, Riki, Spirit Breaker.

* Anti-Mage Blinks directly into Magnetic Field, bypassing its protection.
* Anti-Mage's high mobility allows him to deal with Tempest Double while it is split-pushing.
* Anti-Mage's Battle Fury cleans up Arc Warden's Necronomicon summons, and Counterspell protects him from Necronomicon Warrior's Last Will.
Additional:
* Arc Warden's high reliance on casting spells leads him to be dependent on mana, which Anti-Mage can easily burn with Mana Break.
* Blink mitigates the threat of Flux slow and allows Anti-Mage to close the distance between himself and Arc Warden.
* Anti-Mage's ability to farm quickly allows him keep up with Arc Warden's farm while also de-pushing the lanes Arc Warden shoves in with Tempest Double.
* Counterspell significantly reduces the effectiveness of Arc Warden's magic damage.

* 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

* Squishy heroes or heroes without hard disables or silences: Shadow Demon, Shadow Fiend, Venomancer, Ancient Apparition etc.

* Storm Spirit can hunt down Arc Warden with his Ball Lightning and kill him quickly due to his lack of escape abilities.
* None of his abilities are effective against Storm Spirit, as they can be evaded with Ball Lightning.

* Heroes that are hard to kill without lockdown: Puck, Weaver.

* A well-timed use of The Swarm provides vision over heroes with high mobility: Anti-Mage, Arc Warden, Dark Seer.

* Arc Lightning allows Zeus to get farm in lane against Shadow Fiend without coming into the range of his Shadowrazes.
* Lightning Bolt can be used to heavily harass Shadow Fiend when he tries to get a last hit.
* Thundergod's Wrath and Lightning Bolt can be used to detect Shadow Fiend if he tries to escape with Shadow Blade.

* Void can be used to cancel Requiem of Souls.
* Crippling Fear prevents Shadow Fiend from using Shadowraze or Requiem of Souls.
* With Dark Ascension and Gem of True Sight, Night Stalker can find and kill Shadow Fiend easily. He is also a tanky hero that can fight Shadow Fiend at any stage of the game.

* Enfeeble can be used to decrease Shadow Fiend's already abysmal level one damage even further, preventing him from getting farm and Necromastery stacks.
* Brain Sap allows Bane to heavily harass Shadow Fiend.
* Nightmare allows Bane to set up some early ganks onto Shadow Fiend.
* Fiend's Grip enables Bane to completely take Shadow Fiend out of a fight and potentially even kill him, even through Black King Bar.

* Lacking escaping mechanisms, being dependent on fair positioning and channeling for his ultimate, its easier to Warlock with your long range crowd control abilities to lock the Shadow Fiend down to your team.

* Shadow Fiend, a normal Shadow Blade builder often relies on its invisibility to escape fights. Corrosive Haze reveals Shadow Fiend and also weakens his already low armor.

* Magnetic Field is useless against melee heroes, so Lycan can attack Arc Warden without missing.
* Flux doesn't affect Lycan that much, because Shapeshift grants immunity to slows and because he is never alone.
* If their Tempest Double has been called, Lycan can still kill Arc Warden before the double expires.

* Decrepify prevents Shadow Fiend from attacking for its duration, potentially preventing him from getting a kill.
* Nether Ward can do heavy damage to Shadow Fiend if he tries to cast his Requiem of Souls and spamming Shadowraze.
Additional:
* Decrepify prevents Shadow Fiend from attacking for its duration, potentially preventing him from getting a kill.
* Nether Ward can do heavy damage to Shadow Fiend if he tries to cast his Requiem of Souls and his Shadowraze.

* Bounty Hunter can absolutely destroy a Shadow Fiend's game by ganking his midlane with Shadow Walk, Jinada and Shuriken Toss.
* If his lane goes bad, a Shadow Fiend usually goes to the jungle. Follow him with Shadow Walk and take half of his experience.
* Shuriken Toss is a good way to interrupt Shadow Fiend's long cast animation on Requiem of Souls.
Additional:
* Shuriken Toss can be used to cancel Requiem of Souls.
* Shadow Walk and Jinada allow Bounty Hunter to gank Shadow Fiend early on
* Track prevents Shadow Fiend from escaping with Shadow Blade.

* Kraken Shell dispels both Shadowraze's damage amplification stacks and Requiem of Soul's damage reduction (provided Tidehunter has taken enough damage).
* Ravage cancels Requiem of Souls if Shadow Fiend isn't protected by Black King Bar.
Additional:
* Kraken Shell dispels the damage amplification stacks of Shadowraze as well as the damage reduction from Requiem of Souls (provided he has taken enough damage).
* Anchor Smash reduces Shadow Fiend's large attack damage, Kraken Shell makes Tidehunter the last target Shadow Fiend wants to attack.
* Ravage can easily cancel Requiem of Souls if Shadow Fiend isn't protected by Black King Bar.

* Luna's Moon Glaives allow her to clear Arc Warden's Tempest Double.
* Luna's short range and fast movement speed allow her to fight Arc Warden inside his Magnetic Field.

* Heroes with high burst damage: Lina, Lion, Luna, Nyx Assassin, Queen of Pain.

* Chaos Knight can dispel Flux with Phantasm.
* Chaos Knight can use Reality Rift to pull Arc Warden out of Magnetic Field.
* Once Chaos Knight jumps on Arc Warden with Reality Rift, Arc Warden struggles to escape due to low mobility.

* Heroes who rely on fast attack speed will also trigger Counter Helix frequently: Faceless Void, Troll Warlord, Anti-Mage, Juggernaut, Arc Warden, Morphling

Additional:
* Magnetic Field doesn't provide a protection against Berserker's Call and Counter Helix and his high attack speed together with Tempest Double will often trigger Counter Helix.

* Berserker's Call and Counter Helix allow Axe to kill Shadow Fiend if he stands too close to a creep wave.
* Battle Hunger is very strong against Shadow Fiend in the early game because Shadow Fiend's low attack damage makes it hard for him to get last hits.
* Axe's naturally high strength and health regeneration will be enough to tank a lot of Shadow Fiend's damage in the early game.

* Glimpse and Kinetic Field allows Disruptor to set up some early kills onto Shadow Fiend.
* Static Storm can be used to cancel the cast of Requiem of Souls.

* Song of the Siren stops him from acting and her illusions can push better than him because Mirror Image has a longer duration.
* Arc Warden does not often build Radiance, which is useful for illusions and countering illusion pushes.
* Mirror Image dispels Flux or prevents Flux's slow.
Additional:
* Her illusions can push better than Arc Warden's Tempest Double because Mirror Image has a longer duration.
* Mirror Image dispels Flux, and the illusions stop Flux from working.

* He can't take you very easily, and his nukes are not strong enough to deal with Centaur Warrunner.
* Centaur Warrunner deals huge AoE damage and applies an AoE disable through Hoof Stomp, affecting the double as well the main Arc Warden.
* Magnetic Field is not very effective against melee heroes.
* This ability also increases his allies' attack speed, meaning Retaliate will deal more damage.
* Stampede catches him easily due to the lack of escape mechanisms.

* Shadow Fiend is lack of mobility and low base health, make him a prime target for early ganks.

* Flux is paused if even one illusion remains near Phantom Lancer. It can also be dispelled with Doppelganger.
* Phantom Lancer can also easily dodge an activated Spark Wraith, or use his illusions to trigger it safely.
* Phantom Rush allows Lancer to quickly get inside of Arc Warden's Magnetic Field.
* Phantom Lancer and his clones are able to quickly drain Arc Warden of his mana with a Diffusal Blade. This means Warden's Tempest Double will also be summoned without mana.
Additional:
* Doppelganger dispels Flux.
* Phantom Rush closes the distance between Phantom Lancer and Arc Warden.
* Juxtapose overwhelms Arc Warden and nullifies his kit which is only effective against isolated opponents.

* During the laning stage Laser will reduce Shadow Fiend's last hits, preventing him from getting Necromastery souls.
* Shadow Fiend has low health and is vulnerable to Tinker's high magic burst.
Additional:
* The blind from Laser prevents Shadow Fiend from attacking for its duration, potentially preventing him from getting a kill.
* Scythe of Vyse can be used to prevent Shadow Fiend from casting Requiem of Souls.
* A combination of Tinker's abilities and his items (like the Dagon 5 and Ethereal Blade combo) can kill Shadow Fiend quickly.

* Requiem of Souls is easily interrupted by Boundless Strike, due to its long cast time.
* Shadow Fiend's lack of mobility and escape makes him an easy target to ambush with Primal Spring, especially during laning stage.
* Being close means he cannot use all three razes on you before you get your Jingu Mastery stacks.

* 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.

* Heroes that have small health pools and little to no escape mechanisms are even easier prey for Necrophos. Ghost Shroud's slow will allow him to catch him with them, and get nuked down with his abilities, even preventing retaliation due to Reaper's Scythe's stun. Such heroes include Crystal Maiden, Witch Doctor, Warlock or Shadow Fiend.

* Heroes with channeling spells because Shadow Fiend has nothing to cancel channeling: Bane, Enigma, Pudge, Shadow Shaman.

* Heroes who depends on illusions and summons: Naga Siren, Terrorblade, Arc Warden,Broodmother.

* Heroes with long animations can be frequently interrupted with Cold Snap: Earthshaker, Monkey King, Shadow Fiend Lina

* Heroes that can gank Shadow Fiend in the early game: Earth Spirit, Nyx Assassin, Riki, Spirit Breaker.

* Heroes with high burst damage: Lina, Lion, Luna, Nyx Assassin, Queen of Pain.

* Squishy core heroes (Shadow Fiend, Sniper, etc)

* Heroes who lack escape mechanisms or disables are all easy targets for Phantom Assassin if they are not careful. Look for Luna, Venomancer and Shadow Fiend and try to catch them off guard.

* Heroes with high burst damage: Lina, Lion, Luna, Nyx Assassin, Queen of Pain.

* Heroes with high burst damage: Lina, Lion, Luna, Nyx Assassin, Queen of Pain.

* Heroes with channeling spells because Shadow Fiend has nothing to cancel channeling: Bane, Enigma, Pudge, Shadow Shaman.

* Heroes without escape mechanism: Shadow Fiend, Alchemist

Additional:
* Earthshock prevents Shadow Fiend from escaping after Ursa used his Blink Dagger to get on top of him.
* Overpower and Fury Swipes allow Ursa to quickly kill Shadow Fiend.
* Enrage keeps Ursa alive in a manfight with Shadow Fiend and allows him to stay close, even if Shadow Fiend uses Requiem of Souls.

* Heroes with summons or illusions to counter Flux, such as {Hero ID:Beastmaster} , Chen, or Shadow Demon.

* Heroes with high physical damage output but lack of reliable escape mechanisms are always a good target for a solo gank: Sniper, Shadow Fiend, Troll Warlord, Drow Ranger. Those heroes, however, are dangerous if they manage to close the gap, so take caution.

* Charge of Darkness allows Spirit Breaker to gank Shadow Fiend in the early game, preventing him from getting Necromastery stacks.
* Nether Strike and Charge of Darkness can be used to prevent Shadow Fiend from casting Requiem of Souls.

* Nethertoxin breaks both Necromastery and Presence of the Dark Lord, reducing his damage massively.
* Corrosive Skin gives Viper bonus Magic Resistance against Shadowraze and Requiem of Souls.
* Viper can easily take advantage of Shadow Fiend's lack of escape and mobility spells with Viper Strike and Poison Attack. Poison Attack also serves as a great way to harass Shadow Fiend.

* Rolling Thunder hits Arc Warden, his Tempest Double and any allies through Magnetic Field.
* Rolling Thunder also causes Pangolier to take no damage from existing stacks of Flux as well as clear all Spark Wraiths on the way.

* Chen in the early game is a faster pusher than Arc Warden until Arc Warden buys Maelstrom or Necronomicon.

* Dragon Tail can be used to cancel Requiem of Souls.
* Breathe Fire reduces Shadow Fiend's damage even further.
* Dragon Knight's high strength and Dragon Blood means that he'll be able to tank Shadow Fiend's right clicks.