Alolan Muk is the premier specially defensive Pokemon for Poison teams by virtue of its above-average bulk and decent offensive presence. Additionally, its secondary Dark typing gives it a very important immunity to Psychic while leaving it with a single weakness in Ground. Alolan Muk's great bulk is only enhanced by its ability to efficiently run an Assault Vest, allowing it to serve as a great switch-in to strong special attackers such as Mega Charizard Y. Access to Pursuit allows Alolan Muk to trap and eliminate otherwise dangerous Psychic-types such as Latios as well as Ghost-types like Blacephalon with certainty. Alolan Muk also has access to a strong STAB Knock Off, allowing it to remove the foe's item. This allows it to be very useful against Pokemon that rely on their items such as Eviolite Chansey and Choice-locked Pokemon such as Choice Scarf Greninja. Alolan Muk's ability Poison Touch allows it to potentially wear down switch-ins such as Mantine by granting its contact moves a 30% chance to poison and stacks with Poison Jab for an overall 51% chance to poison. Despite its above-average special bulk, however, Alolan Muk has no way to recover its HP, so it can often be quickly worn down. On top of this, Alolan Muk's physical bulk leaves a lot to be desired and can be exploited by strong physical attackers such as Mega Gallade. Alolan Muk's Speed is also very lackluster, leading to it failing to outspeed just about any offensive Pokemon and certain problematic walls such as Celesteela.
name: Assault Vest (Poison)
move 1: Pursuit
move 2: Knock Off
move 3: Poison Jab
move 4: Fire Blast / Shadow Sneak
item: Assault Vest
ability: Poison Touch
nature: Sassy / Careful
evs: 248 HP / 12 Def / 248 SpD
Pursuit enables Alolan Muk to trap and pressure Psychic-types such as Alolan Raichu as well as general special attackers that it forces out such as Magnezone. Knock Off is usually Alolan Muk's strongest STAB move and can be useful for removing items such as Eviolite and Leftovers from the foe. Poison Jab's considerably high chance to poison the foe allows it to be a good secondary STAB move that can wear down many of Alolan Muk's switch-ins, such as Mega Sableye. Fire Blast offers useful coverage to hit Pokemon such as Mega Scizor and Ferrothorn. Its main purpose, however, is to avoid Alakazam's Counter, allowing Alolan Muk to safely break its Focus Sash and proceed to trap it. Although weak, Shadow Sneak is a decent option that allows Alolan Muk to fire off a move before going down, since it's very slow, and pick off weakened Psychic-types such as Victini.
The given EV spread maximizes Alolan Muk's special bulk and allows it to always survive Choice Scarf Victini's V-create after a round of Stealth Rock. Poison Touch gives Alolan Muk's contact moves a respectable chance to poison defensive switch-ins such as Landorus-T. Assault Vest enhances Alolan Muk's special bulk to incredible levels, allowing it to fully serve as an amazing check to many of the metagame's special attackers such as Tapu Koko. A Sassy nature is used in order to increase Alolan Muk's Special Defense while not sacrificing Fire Blast's power. However, if a physical move is run over it, then a Careful nature is preferred.
Alolan Muk's main role is that of a special pivot, so it is safe to bring it in on special attackers such as Tapu Koko and Porygon-Z while it's healthy. However, since it has no way of recovering HP, Alolan Muk should not be worn down unnecessarily throughout the match. Avoid switching into entry hazards unless necessary in order to preserve HP. It is especially important to preserve Alolan Muk in matchups where it is needed to trap dangerous Pokemon such as Blacephalon and Latios, as these Pokemon have a much easier time against the rest of the team. Because of this, Alolan Muk is absolutely crucial in the Psychic matchup, as its stops Pokemon like Mew from simply using their super effective STAB moves and it puts consistent pressure in the matchup thanks to Knock Off and Pursuit. When trapping frailer Psychic-types such as Latios, it is always better to use Pursuit right away, as it will heavily damage them even if they choose to stay in. Alakazam should never be Pursuit trapped while at full HP, however, as it will always survive a hit thanks to its Focus Sash and KO Alolan Muk back with its Counter. Lastly, Alolan Muk should avoid burns from Will-O-Wisp and Scald, as this will cripple its otherwise respectable Attack stat and allow it to become setup bait for certain Pokemon such as Mega Charizard X.
Mega Venusaur is a physically defensive tank that synergizes very well with Alolan Muk, as it can stomach physical attacks with its bulk as well as take on Ground-types such as Hippowdon and Swampert. Alolan Muk, on the other hand, can take on Psychic-types as well as most special attackers that can break past Mega Venusaur such as Volcarona. Toxapex completes an amazing defensive core between the two of them, as Regenerator in tandem with its ability to set Toxic Spikes goes hand in hand with Alolan Muk's ability to force switches and take on Pokemon such as Porygon-Z for it. Additionally, Toxapex can serve as a good physical switch-in and even burn physical attackers with Scald. Crobat is a good teammate, sporting a notable immunity to Ground, utility in the form of Taunt and Defog, and access to Flying-type STAB moves, allowing it to deal with stops to Alolan Muk such as Keldeo. Nidoking is a great special wallbreaker that can specifically eliminate Steel-types that trouble Alolan Muk, such as Skarmory, Ferrothorn, and Celesteela, as well as provide Stealth Rock support for the team. Thanks to the presence of Pokemon such as Skarmory and Landorus-T, Alolan Muk often struggles in the Flying matchup. Nihilego is a great teammate that can cover this, as its coverage is almost impossible to wall in this matchup, and it can also set up its own Stealth Rock. Lastly, Gengar can free Alolan Muk's load in the Psychic and Ghost matchups thanks to its great offensive typing and can take on more offensive Pokemon such as Mega Gallade after minimal chip damage.
Rock Slide is an option that allows Alolan Muk to check Pokemon such as Volcarona and Mega Charizard Y much more efficiently, exploiting their massive Rock weakness.
Checks and Counters
**Ground-types**: Many Ground-types such as Excadrill, Landorus, and Garchomp can take advantage of Alolan Muk's sole weakness in Ground and KO it with their STAB moves.
**Physically Defensive Pokemon**: Although Alolan Muk is still able to remove their items, Pokemon such as Skarmory and Toxapex can threaten Alolan Muk due to their good physical bulk.
**Physical Attackers**: Alolan Muk's average Defense stat means it struggles to switch into most strong physical attacks, such as Terrakion and Mega Gallade's Close Combat and Mega Diancie's Diamond Storm.
**Burns**: Burns from the likes of Mega Sableye's Will-O-Wisp and Toxapex's Scald will cripple Alolan Muk and prevent it from having an offensive presence.