Mewtwo @ Life Orb (Fast Special Sweeper)
Ability: Unnerve
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Psystrike
- Shadow Ball
- Aura Sphere
- Ice Beam
Psystrike is a good STAB option for special walls such as Kyogre. Shadow Ball beats other Psychic types, Aura Sphere beats Dark types, and Ice Beam adds extra OHKOs M-Salamence, Landrous, Rayquaza, etc.
Metagross-Mega @ Metagrossite (Fast Physical Sweeper/Wallbreaker)
Ability: Tough Claws
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Iron Head
- Toxic
- Brick Break
- Bullet Punch
I decided to do Iron Head instead of Meteor Mash, because I already have a low accuracy attack(Zen Headbutt). Brick Break covers steel and dark types, and Bullet Punch for priority.
Arceus-Fairy @ Pixie Plate (Tank/Hazard Remover)
Ability: Multitype
EVs: 252 HP / 252 Def / 4 SpA
Bold Nature
IVs: 0 Atk
- Calm Mind
- Defog
- Recover
- Judgment
Maximum defense + Calm Mind helps Arceus take both physical and special hits. Defog removes hazards. Recover, well, for recovery. And Judgment for STAB.
Groudon-Primal @ Red Orb (Bulky Physical Sweeper/Xearneas Counter)
Ability: Desolate Land
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Roar
- Hone Claws
- Precipice Blades
- Stone Edge
Roar can remove Power Herb Xearneas' stat changes by switching it out. Hone Claws provides perfect accuracy for its attacks. Precipice Blades for STAB, and Stone Edge covers Flying Types.
Kyogre-Primal @ Blue Orb (Bulky Special Sweeper)
Ability: Primordial Sea
EVs: 252 HP / 252 SpA / 4 SpD
Modest Nature
IVs: 0 Atk
- Scald
- Origin Pulse
- Thunder
- Ice Beam
Primal Kyogre's defense isn't nearly as good as its special defense, so Scald comes in handy. Origin Pulse provides a more powerful Water type attack. Ice Beam covers grass and dragon types. And Thunder deals with other water types.
Marshadow @ Focus Sash (Fast Physical Sweeper/Boost Steeler)
Ability: Technician
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Spectral Thief
- Close Combat
- Shadow Sneak
- Ice Punch
Marshadow's main purpose is to steel boosts from setup mons such as Arceus with Spectral Thief. Close Combat for a more powerful STAB, Shadow Sneak for priority, and Ice Punch for extra coverage. I gave it Focus Sash so it can survive hits from speed-boosted opponents and proceed with Spectral Thief.