Counter that Pokémon! SM v.2

Mantine @ Leftovers
Ability: Water Absorb
EVs: 252 HP / 4 Def / 252 SpD
- Scald
- Roost
- Air Slash
- Haze

Can tank any hit even at +2 and use Haze; can then easily stall out Volcarona with Roost.

Eelektross @ Assault Vest
Ability: Levitate
EVs: 252 HP / 252 SpA / 4 SpD
Modest Nature
IVs: 0 Atk
- Thunderbolt
- Volt Switch
- Giga Drain
- Flamethrower

Can tank anything Mantine throws at it and then KO with Thunderbolt.

252+ SpA Eelektross Thunderbolt vs. 252 HP / 252+ SpD Mantine: 316-376 (84.4 - 100.5%) -- 6.3% chance to OHKO

0 SpA Mantine Scald vs. 252 HP / 0 SpD Assault Vest Eelektross: 58-69 (15.5 - 18.4%) -- possible 6HKO

Zygarde-10% @ Choice Band
Ability: Aura Break
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Extreme Speed
- Thousand Arrows
- Outrage
- Superpower

Giga Drain is a 3HKO while this dog is faster and can OHKO with Thousand Arrows

Mamoswine @Life Orb
Ability: Thick Fat
EVs: 200 HP / 148 Atk / 162 Def
Naive Nature
-Ice Shard
-Icicle Crash
-Earthquake
-Freeze Dry

Tanks your attacks and OHKOs with priority Ice Shard. If you beat the prio with Extreme Speed, Mamoswine still tanks and picks up the OHKO.

Bronzong @ Leftovers
Ability: Levitate
EVs: 252 HP / 4 Def / 252 SpD
Sassy Nature | 0 Spe IV
- Gyro Ball
- Toxic
- Stealth Rock
- Earthquake

Icicle Crash won't even 5HKO most of the time due to Leftovers recovery. Gyro Ball is an easy 2HKO.

Moltres @ Life Orb
Ability: Flame Body
EVs: 252 Atk / 4 Def / 252 Spe
Timid Nature
- Fire Blast
- Hurricane
- Roost
- Hidden Power Grass

None of Bronzong's moves do significant damage even with Stealth Rock up, and Fire Blast is an OHKO

Aerodactyl @ Aerodactylite
Ability: Unnerve
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Stone Edge
- Wing Attack
- Earthquake
- Roost

Mega Aerodactyl is faster and it can OHKO Moltres with Stone Edge.

Solrock @ Leftovers
Ability: Levitate
252 HP / 252 Def / 4 SpD
- Rock Slide
- Morning Sun
- Will-O-Wisp
- Reflect

After Reflect is up, Solrock will have no trouble tanking Aerodactyl's attacks and stalling with Morning Sun. It can then further cripple Aerodactyl with a burn or just 2HKO it with Rock Slide.

Gastrodon @ Choice Specs
Ability: Storm Drain
EVs: 252 HP / 252 SpA / 4 SpD
Modest Nature
IVs: 0 Atk
- Surf
- Ice Beam
- Earth Power
- Hidden Power [Electric]

Takes little damage from Solrock and is not bothered much by a burn. Can easily OHKO with Surf.

Goodra @ Assault Vest
Ability: Sap Sipper
252 HP / 4 Atk / 252 SpD
Careful Nature
- Power Whip
- Iron Tail
- Outrage
- Earthquake

Ice Beam will 4HKO at best and Power Whip will OHKO uninvested Gastrodon.

Gogoat @Leftovers
Ability: Sap Sipper
EVs: 252 HP / 252 Def / 4 SpD
Impish Nature
-Milk Drink
-Toxic
-Horn Leech
-Earthquake

Gogoat can tank all of Goodra's attacks and then stall it out with Toxic/Milk Drink. Even better if it switches in on Power Whip and it picks up an Atk boost.

Crobat @ Black Sludge
Ability: Infiltrator
EVs: 248 HP / 48 Def / 212 Spe
Jolly Nature
- Brave Bird
- Taunt
- Toxic
- Roost

lol

Jirachi @ Choice Scarf
Ability: Serene Grace
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Iron Head
- Zen Headbutt
- U-Turn
- Fire Punch

Volcanion @ Expert Belt
Ability: Water Absorb
EVs: 252 SpA / 252 Spe / 4 SpDef
Modest Nature
-Fire Blast
-Steam Eruption
-Sludge Bomb
-Hidden Power Electric

252 Atk Jirachi Zen Headbutt vs. 0 HP / 0 Def Volcanion: 93-111 (30.8 - 36.8%) -- 69.3% chance to 3HKO

and then Fire Blast murders it

boom

Alright, just a few changes and viola!

Volcanion @ Choice Specs
Ability: Water Absorb
EVs: 252 SpA / 252 Spe / 4 SpDef
Timid Nature
-Fire Blast
-Steam Eruption
-Sludge Bomb
-Earth Power

HP Electric 2HKO's. My Volcanion outspeeds and OHKO's with Earthpower

Goodra @ Choice Specs
Ability: Sap Sipper
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature
- Draco Meteor
- Fire Blast
- Sludge Wave
- Dragon Pulse

Volcanion doesn't 2HKO, while Goodra OHKOes w/ DM or Tbolt.

Chansey @ Eviolite
Ability: Natural Cure
EVs: 4 HP / 252 Def / 252 SpD
Bold Nature
- Toxic
- Soft-Boiled
- Seismic Toss
- Heal Bell

Too tired to think of a better counter so lol

Stomachs anything Goodra throws at it, heals back damage, cures status hax with Heal Bell, and wins with Toxic and Toss.

Espeon @ Leftovers
Ability: Magic Bounce
EVs: 8 HP / 248 SpA / 252 Spe
Timid Nature
- Calm Mind
- Psyshock
- Shadow Ball
- Morning Sun

Doesn't have to worry about Toxic and can heal back any damage from Toss. Wins with Psyshock, especially if it takes the time to boost with Calm Mind.

Raticate - Alolan @ Figy Berry
Ability: Gluttony
EVs: 16 HP / 252 Atk / 240 Spe
Jolly Nature
- Crunch
- Return
- Super Fang
- Sucker Punch

kek

Mimikyu @ Life Orb
Ability: Disguise
4 HP / 252 Atk / 252 Spe
Jolly Nature
- Swords Dance
- Play Rough
- Shadow Sneak
- Wood Hammer

With LO damage, Sucker Punch is a 3HKO, but that's after Mimikyu's disguise has been busted. Play Rough is an OHKO even unboosted.