Groudon @ Leftovers
Trait: Drought
EVs: 32 HP / 84 Atk / 184 Def / 208 SDef
Impish Nature (+Def, -SAtk)
- Stealth Rock
- Earthquake
- Fire Punch
- Stone Edge
Ho-Oh @ Life Orb
Trait: Regenerator
EVs: 128 Atk / 252 SAtk / 128 Spd
Rash Nature (+SAtk, -SDef)
- Thunder
- Sacred Fire
- Brave Bird
- SolarBeam
Kyogre @ Choice Scarf
Trait: Drizzle
EVs: 4 HP / 252 SAtk / 252 Spd
Modest Nature (+SAtk, -Atk)
- Thunder
- Ice Beam
- HP Fighting
- Surf
Ho-Oh: Basically just use the weather to abuse Ho-Oh's movepool. Use Thunder in rain, and Solarbeam in sun. Sacred Fire for Main Stab against all that take fire neutrally and against pokemon with low special defense. Brave Bird so you don't get walled into a special wall. Regenerator too, well regain life so Life Orb doesn't destroy you.
Kyogre: Thunder because of the perfect accuracy in rain and as coverage, Ice Beam for dragons, and grounds that Ho-Oh and Groudon don't want to deal with. HP Fighting for Ice types that can kill the other two. Surf for Main Stab.
Groudon: Sets up Rocks, and physical wall, takes electric types like a boss. Earthquake for main stab, and Fire Punch for ferrothorns that can cripple Ho-Oh with twave or 1hko Kyogre with a Power Whip. Stone Edge for le coverage.