Counter that Pokémon!

Alakazam @ Life Orb
Timid Nature
Ability: Magic Guard
EVs: 4 HP / 252 SpA / 252 Spe
- Psyshock
- Thunderbolt
- Shadow Ball
- Focus Blast

Muk-Alola @ Assault Vest
Careful Nature
EVs: 248 HP / 36 Atk / 28 Def / 192 SpD / 4 Spe
- Knock Off
- Pursuit
- Poison Jab
- Rock Slide

Knock Off does anwhere from 168 to 198% dmg while Focus Blast is 0.3% chance at a 4hko.

Mawile @ Mawilite
Ability: Intimidate
EVs: 92 HP / 252 Atk / 164 Spe
Adamant Nature
- Swords Dance
- Play Rough
- Sucker Punch
- Thunderpunch

Steelix @ Steelixite
Ability: Sturdy
EVs: 252 HP / 208 Atk / 48 SpD
Brave Nature
- Stealth Rock
- Gyro Ball
- Earthquake
- Curse

Mantine @ Leftovers

252 HP/198 Defense/54 Special Defense
Ability: Swift Swim
Calm Nature

-Scald
-Roost
-Haze
-Mirror Coat

Cradily @ Wide Lens
Jolly Nature
Ability: Storm Drain
EVs: 252 HP / 4 SpD / 252 Spe
- Recover
- Stone Edge
- Stealth Rock
- Toxic

Escavalier @ Leftovers
Ability: Overcoat
EVs: 252 HP / 52 Atk / 204 SpD
Adamant Nature
- Megahorn
- Iron Head
- Protect
- Knock Off

Moltres @ Leftovers
Timid Nature
Ability: Pressure
EVs: 248 HP / 36 Def / 224 Spe
- Roost
- Defog
- Flamethrower
- Toxic

Toxapex @ Black Sludge
Ability: Regenerator
EVs: 252 HP / 4 Def / 252 SpD
Calm Nature
- Scald
- Haze
- Recover
- Toxic

Toxicroak @ Life Orb

Jolly Nature
192 Attack/252 Speed/60 Special Attack
Ability: Dry Skin

-Taunt
-Sucker Punch
-Earthquake
-Icy Wind

Quagsire @ Leftovers
Ability: Unaware
EVs: 252 HP / 252 Def / 4 SpD
Relaxed Nature
- Scald
- Earthquake
- Recover
- Toxic

Roserade @ Black Sludge
Sassy Nature
Ability: Technician
EVs: 252 SpA / 252 SpD / 4 Spe
- Aromatherapy
- Giga Drain
- Substitute
- Hidden Power Fire

Heatran @ Leftovers
Ability: Flash Fire
EVs: 252 HP / 4 SpD / 252 Spe
Timid Nature
- Lava Plume
- Toxic
- Taunt
- Earth Power

Gliscor @ Toxic Orb
Ability: Poison Heal
EVs: 244 HP / 52 Def / 76 SpD / 136 Spe
Jolly Nature
- Stealth Rock
- Earthquake
- Toxic
- Roost

Sigilyph @ Life Orb
Ability: Magic Guard
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Psychic
- Heat Wave
- Roost
- Ice Beam

Sharpedo @ Sharpedonite
Ability: Speed Boost
EVs: 4 HP / 252 Atk / 252 Spe
Adamant Nature
- Waterfall
- Crunch
- Aqua Jet
- Ice Fang

Tapu Fini @ Leftovers
Ability: Misty Surge
EVs: 248 HP / 16 Def / 12 SpA / 40 SpD / 192 Spe
Calm Nature
- Defog
- Moonblast
- Scald
- Taunt

Amoonguss @ Black Sludge
Ability: Regenerator
EVs: 248 HP / 56 Def / 204 SpD
Calm Nature
- Spore
- Giga Drain
- Hidden Power Fire
- Sludge Bomb

Espeon @ Choice Specs
Ability: Magic Bounce
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Psyshock
- Dazzling Gleam
- Hidden Power [Fire]
- Shadow Ball

Tyranitar @ Assault Vest
Ability: Sand Stream
EVs: 224 HP / 32 Atk / 252 SpD
Careful Nature
- Rock Slide
- Crunch
- Pursuit
- Earthquake

252 SpA Choice Specs Espeon Dazzling Gleam vs. 224 HP / 252+ SpD Assault Vest Tyranitar in Sand: 84-100 (21.1 - 25.1%) -- 0% chance to 4HKO
Possible damage amounts: (84, 86, 86, 88, 88, 90, 90, 92, 92, 94, 94, 96, 96, 98, 98, 100)