* Skywrath Mage should have the upper hand against Vengeful Spirit with Ancient Seal.
* Vengeful is highly dependant on her abilities and has no natural means to deal against silences.
* Her low attack range allows Skywrath Mage to easily bully her out of the lane.

* 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.

* Heroes who have a high mobility (Queen of Pain, Storm Spirit, Slark, etc.).

* 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.

* Nethertoxin disables Vengeance Aura.
* Vengeful Spirit has no mobility spells aside from Nether Swap, which Viper can take advantage of with his slows.
* Viper can easily bully Vengeful Spirit out of a lane with Poison Attack.
Additional:
* Nethertoxin prevents the attack damage bonus from Vengeance Aura and the components of Nether Swap.
* Both Magic Missile and Wave of Terror are counteracted by Corrosive Skin, making Vengeful Spirit's fighting harder against Viper.

* Viper can bully Alchemist out of mid lane quite easily, forcing him to either retreat into jungle, or stay harassed in lane, and get very few last hits. Vipers break also completely disables Greevil's greed which prevents Alchemist to earn his amazing amounts of money.

* 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.

* Past the mid game, an isolated Vengeful Spirit makes for an easy kill for Anti-Mage.
* Magic Missile is the only disable Vengeful Spirit has against Anti-Mage, but he can either Blink away to disjoint the stun or reflect it back against Vengeful Spirit with Counterspell.
* Nether Swap isn't very effective against Anti-Mage - if used offensively, Anti-Mage can simply blink away to safety, and if used defensively, Blink's low cooldown allows him to persistently chase as well.

* 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.

* 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.

* 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.

* 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 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.
Additional:
* 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.

* Vendetta disables Vengeance Aura and allows him to attack Vengeful Spirit with Impale and Mana Burn.
* Spiked Carapace is easy to use against a Wave of Terror or Magic Missile.

* 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.

* Ball Lightning disjoints an incoming Magic Missile, avoids Wave Of Terror, and allows Storm Spirit to easily escape if he ever gets Nether Swapped.

* Nether Swap triggers extra damage from Rupture.
* Blood Rite sets up while Vengeful Spirit using her Nether Swap within a timed correctly.

* Vengeful Spirit should carefully consider whether to use her Nether Swap on Tidehunter, as it can easily position him for a Ravage on Vengeful Spirit and her allies.
* Due to Magic Missile's high damage, Kraken Shell will often proc and clear Tidehunter's debuffs.

* Magic Missile has a considerably long cast time, making it difficult to stop Charge of Darkness with it.
* Other than Magic Missile, Vengeful Spirit has no way of canceling Nether Strike.

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

* 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.

* 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.

* 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.

* Magic Missile is a solid damage source and lockdown that fits nicely with Rubick's kit.
* Rubick also acquires the secondary Magic Missile with Aghanim's Shard.
* Wave of Terror can be used to scout an area to prevent juking or initiate with Telekinesis, as well as reducing the armor of enemy team during a teamfight.
* Nether Swap does what it does - saving an ally from danger, initiating on an enemy, or helping with caughting a fleeing hero.
* With Aghanim's Shard, Rubick can lift himself up and drop quickly to a place of safety after the swap. Note that Rubick can only choose to either disable the enemy or save himself at one time with Telekinesis.
Additional:
* All of Vengeful Spirit abilities are very good for Rubick to Spell Steal:
* Magic Missile provides an additional nuke/disable to pair with Fade Bolt and Telekinesis, respectively.
* Wave of Terror serves as a good scouting/armor reduction skill that Rubick and his team can benefit from.
* Nether Swap complements Rubick's mobility and pairs well with other mobility items he usually builds. He can also use it to save an ally from danger.

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

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

* Frail heroes who lacks mobility: Crystal Maiden, Enigma, Dark Willow, Vengeful Spirit.

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

* Heroes who relies on illusions and summons (Beastmaster, Chaos Knight, etc.).

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

* 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.

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

* 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 relies on illusions and summons (Beastmaster, Chaos Knight, etc.).

* 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.

* Heroes who have a high mobility (Queen of Pain, Storm Spirit, Slark, etc.).

* Vengeful Spirit has no strong AoE nuke or disable against Phantom Lancer's Illusions.
* Phantom Lancer is a natural Diffusal Blade carrier, which reduces Vengeful Spirit's low mana pool very quickly, leaving her defenseless.
* Doppelganger can dodge Vengeful Spirit's abilites.
* Phantom Rush with his illusions can chase Vengeful Spirit efficiently.

* Lina can burst Vengeful Spirit down, provided she can land Light Strike Array before Vengeful Spirit lands her Magic Missile.
* Laguna Blade deals massive damage, often being enough to kill a squishy Vengeful Spirit.

* 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.