* Alchemist likes to farm fast and be ahead, unfortunately Lone Druid likes to do the same by taking towers.
* Acid Spray will never prove a threat to Lone Druid or his Spirit Bear.
* Chemical Rage may not prove so useful once Lone Druid procs entangled keeping him in place.
* Monkey King Bar is a very good choice on Lone Druid's Spirit Bear and it directly counters any potential Radiance from Alchemist.
* Assault Cuirass is another very good Spirit Bear item that further makes Alchemist vulnerable to physical damage, which is all Lone Druid does.
* Alchemist is not the kind of hero who wants to go on single target summon units, by the time he has killed the Spirit Bear his teammates might had already been slayed by his teammates. Not to mention Lone Druid can just resummon it, even if he is successful.

* Because of his weak laning phase, Lone Druid absolutely overpowers him in the early to mid game. Lone Druid also directly counters most of his abilities.
* Flux is nullified when the Spirit Bear is nearby.
* Spark Wraith can get soaked by the bear.
* Lone Druid can easily go inside Magnetic Field and punish Zet.

* Quas-Exort Invoker can win the mid lane easily against Alchemist because Quas regeneration will nullify Acid Spray's damage over time and Exort damage bonus will allow Invoker to out last hit Alchemist.

* Invoker's Forge Spirit can negate Flux.
* Provided he does a right combo with Chaos Meteor, Invoker can easily burst down Arc Warden (plus his clone if he spawns it.)
* An early Orchid Malevolence can shut down Arc Warden pretty hard, especially when Invoker has a good lane against him if he kills him early on.
* Deafening Blast and Ice Wall limit's Arc Wardens mobility and damage, crippling him greatly.

* Shadow Dance allows Slark to not be targeted by Unstable Concoction, making Alchemist stun himself and making himself vulnerable to the enemy.
* Dark Pact also allows him to just purge off the stun if timed correctly.
* Essence Shift will steal stats over long durations at a time should Alchemist lack the damage to kill Slark.

* Flux is dispelled by Dark Pact.
* Pounce allows Slark to avoid Spark Wraiths.
* Tempest Double allows Slark to build up Essence Shift stacks, especially when it is being used for split pushing.

* Pugna's Decrepify makes sure that either Alchemist is unable to hit anyone while also being slowed and susceptible to magical damage, or can protect an ally from physical attacks. Besides, Pugna can push early on, when Alchemist is not strong enough to repel it, so by the time Alchemist comes online, he might be forced to sit in base.

* Arc Warden can't use Magnetic Field to stall the damage of Nether Blast on towers, but he can buy Aghanim's Shard to diminish its damage.
* Arc Warden has no innate disables to stop Life Drain and Decrepify
* The short cooldown of both Life Drain and Decrepify also means Pugna can deal with Arc Warden and Arc Warden's clone simultaneously most of the time
* A good Pugna looks to end the match early while Arc Warden, a very item reliant hero, thrives in longer matches.

* 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.

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

* 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.

* Heroes that have doubles or clones such as Arc Warden, Meepo or Lone Druid are vulnerable to Muerta's Gunslinger.

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

* Heroes who depends on illusions and summons: Naga Siren, Arc Warden, Broodmother will struggle against Great Cleave.

* Corrosive Haze followed by Slithereen Crush takes advantage of Alchemist's main weakness, being physical damage before he has the change to improve his surviability with items.
* Bash of the Deep will deal lots of damage during the laning phase.

* Tidebringer will deal lots of damage to Alchemist before he builds physical survivability items.
* Torrent and X Marks the Spot can control Alchemist at all stages of the game before he has Black King Bar.
* Ghostship's rum buff will greatly reduce the Alchemist's damage output in teamfights including his Radiance.

* 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 will struggle to escape due to low mobility and lack of stun.

* Smoke Screen combined with Diffusal Blade leaves Arc Warden effectively useless for a while as he struggles to escape the silence with low mobility.
* With Arc Warden's low mobility, Tricks of the Trade often deal decent damage to him before he moves out of it.

* 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.
Additional:
* Arc Warden's high reliance on casting abilities leads him to be dependent on mana, which Anti-Mage can quickly 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 his Tempest Double.
* Anti-Mage also frequently buys Manta Style, and can use it so dispel Arc Warden's items that can threaten an Anti-Mage like Bloodthorn.
* Counterspell significantly reduces the effectiveness of Arc Warden's magical damage.
* However, do keep in mind that when Arc Warden has a Black King Bar, jumping on him alone may not be the best idea for Invoker as it could put him in a bad position, while Arc Warden summons his doubles and rain damage into him.

* Song of the Siren stops Arc Warden from acting and allows Naga Siren's team to close in on him, past his Magnetic Field.
* Mirror Image dispels Flux. The illusions created from it also disable the slow from Flux if Arc Warden casts it after Mirror Image.
* Arc Warden's playstyle heavily favors split-pushing, which Naga Siren can compete against with her illusions.
Additional:
* Naga Siren's illusions from Mirror Image can depush the lanes pushed by the Tempest Double, relieving the pressure.
* Mirror Image can dispel Flux, and the illusions can stop Flux from working to it's full power.

* 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.

* Heroes who are melee but cannot fight back against Eclipse will really struggle with Luna: Monkey King, Alchemist, Timbersaw.

* 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.
Additional:
* 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.

* Reaper's Scythe can kill Alchemist before Chemical Rage has the time to heal him.
* Ghost Shroud can prevent Alchemist from attacking Necrophos, as well as make him immune to Acid Spray and Unstable Concoction damage.
* Heartstopper Aura will do damage as long as Necrophos is alive based on health percentage, which is a problem for a strength hero such as Alchemist.

* Ice Blast nullifies the health regeneration granted by Chemical Rage, which Alchemist greatly relies on to stay alive in battle.
* Alchemist tends to build Armlet of Mordiggian which can be deadly during Ice Blast.
Additional:
* Ice Blast cancels out Chemical Rage's rapid health regeneration. It can also take advantage of Alchemist's Armlet of Mordiggian toggling, as it will make HP drain insanely fast, essentially killing the bearer in no time.

* Arc Warden cannot take Centaur Warrunner 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. And to make things worse, Magnetic Field also increases Arc Warden and his allies's attack speed, meaning Retaliate will deal more damage.
* Stampede catches Arc Warden easily due to his lack of escape mechanisms. However, Arc Warden can counter this problem with Gleipnir, which is a common item on Arc Warden.

* Chain Frost can deliver high amounts of damage to Arc and his clone

* Skywrath Mage can easily harass Alchemist in the laning phase with multiple Arcane Bolts. Additionally, if Alchemist is in the process of throwing an Unstable Concoction, and has no way to dispel Ancient Seal, the self stun becomes an easy set up for Mystic Flare.
* Caution, however, as a decently farmed Alchemist with {Item ID:Radiance} and {Item ID:Manta Style} can easily send illusions to harass and force Skywrath Mage out.

* Axe can force Alchemist to attack him with Berserker's Call. High attack speed from Chemical Rage will cause Counter Helix to proc multiple times.
* This can get worse if axe has Blade Mail, which then returns all damage to Alchemist himself.
* Axe's abilities can pierce through Black King Bar, which is a common item for Alchemist.
* Berserker's Call grants Axe a huge bonus armor, which greatly counters Alchemist's physical damage for the most part.

* 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.
* The threat of a blink and Berserker's Call may make the real Arc Warden stay further back, thus effectively halving the team's damage output for a while.

* Alchemist is a well-known Radiance carrier among other auras your illusions will benefit from. They also get the extra move speed and reduced base attack time from his Chemical Rage, and it's even better if you can catch him as his own rage is about to expire.
* Disruption will buy enough time for all allies to retreat when Alchemist starts to activate Unstable Concoction.

* Heroes with summons or illusions can counter Flux, such as Beastmaster , Chen, or Shadow Demon.

* Alchemist's reliance on fast attack speed to do single-target damage makes him vulnerable to Static Link. It also goes through Black King Bar, which is a standard item on Alchemist.
* Eye of the Storm is great against high health strength heroes as it reduces their survivability to physical damage.
* Razor has early lane push to counter Acid Spray.

* 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.

* Ember's magic damage build is able to burst down Alchemist due to his low strength gain and Alchemist's normal item pick up.

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

* 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.

* Batrider can harass Arc Warden more easily with Sticky Napalm thanks to it's low cooldown and mana cost and because of Arc Warden's lower durability and mobility.
* Batrider can use Flamebreak to push Arc Warden and Tempest Double out of the Magnetic Field.
* With Firefly combined with Blink Dagger, Batrider can move faster while dealing damage to both Arc Warden and Tempest Double.
* Flaming Lasso allows Batrider to separate Arc Warden from both Magnetic Field and Tempest Double and pull him towards Batrider's team. Aghanim's Scepter upgraded Flaming Lasso also allows Batrider to disable both, real Arc Warden and his Tempest Double and pull them towards Batrider's team. And since Arc Warden is not used to buy Linken's Sphere, this can be a great problem to him.
* Since Arc Warden is not used to buy Black King Bar very ofthen In most of the stages of the game, he will be vulnerable to Batrider's magical damage-over-time output in most of the stages of the game.
* However, Batrider needs to approach Arc Warden carefully as Arc Warden can scout Batrider's location with Spark Wraith. Also, Arc Warden tends to buy Gleipnir which combined with Flux's damage over time can be used to prevent Batrider from even using Blink Dagger.
Additional:
* Batrider can harass Arc Warden more easily with Sticky Napalm thanks to it's low cooldown and mana cost and because of Arc Warden's lower durability and mobility.
* Batrider can use Flamebreak to push Arc Warden and Tempest Double out of the Magnetic Field.
* With Firefly combined with Blink Dagger, Batrider can move faster while dealing damage to both Arc Warden and Tempest Double.
* Flaming Lasso allows Batrider to separate Arc Warden from both Magnetic Field and Tempest Double and pull him towards Batrider's team. Aghanim's Scepter upgraded Flaming Lasso also allows Batrider to disable both, real Arc Warden and his Tempest Double and pull them towards Batrider's team. And since Arc Warden is not used to buy Linken's Sphere, this can be a great problem to him.
* Since Arc Warden is not used to buy Black King Bar very ofthen In most of the stages of the game, he will be vulnerable to Batrider's magical damage-over-time output in most of the stages of the game.
* However, Batrider needs to approach Arc Warden carefully as Arc Warden can scout Batrider's location with Spark Wraith. Also, Arc Warden tends to buy Gleipnir which combined with Flux's damage over time can be used to prevent Batrider from even using Blink Dagger.

* Arc Warden's Flux is meaningless against Meepo who loves to group up. Meepo is also a very good gap closer, so Arc Warden's Magnetic Field becomes useless.

Additional:
* Flux is severely impaired against Meepo because of Divided We Stand.
* Meepo's farming speed and early powerspikes allows him to pressure Arc Warden before he is capable of fighting effectively.
* Without Black King Bar, Earthbind and Poof can finish Arc Warden quickly before he has time to do much.

* Visage can quickly kill heroes with low to medium base armor and no innate escape mechanism. Examples include Alchemist, Crystal Maiden and Zeus.

* Clinkz can use Burning Army in teamfights which will cause a problem for Alchemist.

* 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.

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

* 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:
* 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.

* Heroes without an escape mechanism: Shadow Fiend, Alchemist

Additional:
* Chemical Rage will rarely save Alchemist against Ursa's Fury Swipes.
* Enrage allows Ursa to both be a threat to Alchemist and avoid his over time damage.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Fiend's GAte to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* Heroes with summons or illusions can counter Flux, such as Beastmaster , Chen, or Shadow Demon.

* One of Arc Warden's hardest counters, Arc Warden, who has primarily single target damage, will struggle tremendously against Phantom Lancer:
* 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 close gap to 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 can overwhelm Arc Warden and nullify his kit which is only effective against isolated enemies.

* Alchemist has very bad armor and does not build armor items for the large majority of his build, so Jingu Mastery and Wukong's Command can be very deadly.
* Desolator, Sange and Yasha or Diffusal Blade can all be purchased to increase your damage against Alchemist or just to keep your movement speed high enough to match him while Chemical Rage is active.
* Monkey King is an agility hero and scales with armor, so Acid Spray loses it's effectiveness later in the game.

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

* Melee heroes that get kited easily have hard times dealing with Puck without any lockdowns, as Puck is one of the most mobile heroes. Heroes like Sven, Lifestealer, Ursa and Alchemist may have problems to get to Puck without proper initiation items. They also lack reliable lockdowns, as their disables are easily avoidable for Puck, or are just a soft disable.

* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, Arc Warden, Warlock, Chen

* Untouchable greatly reduces Chemical Rage's attack speed advantage.

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

* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, Kunkka, Alchemist, Troll Warlord, Wraith King, Tiny, Sven.

* Sprout is good for trapping melee carries with no escape abilities: Sven, Alchemist, Lifestealer etc.

* None of Arc Warden's abilities are very effective against Broodmother and her spiderlings.
* A good Broodmother looks to end the match early while Arc Warden, a very item reliant hero, thrives in longer matches.
* Arc Warden has no innate disables to stop Broodmother from lifestealing with Insatiable Hunger and shredding through his relatively lower armor.

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