Set 1: Manaphy @ Damp Rock
Trait: Hydration
Timid Nature
EVs: 252 SpA / 252 Spe / 4 HP
Moves:
-Rain Dance
-Rest
-Scald
-Ice Beam
Start by using Rain Dance. With the Damp Rock, Rain Dance will extend from 5 turns to 8 turns. Once your Manaphy has been afflicted with a status condition (i.e. burn, paralyze, poison) or has taken a lot of damage from attacks, use Rest. Hydration will cause Manaphy to automatically wake up due to Hydration while also fully healing itself. Then, Scald is for STAB, a chance to burn the opponent, and an increase of power due to Rain Dance, so Scald now has a BP of 180. Finally, Ice Beam is for coverage against Grass-Types.
Set 2: Manaphy @ Life Orb
Trait: Hydration
Timid Nature
EVs: 252 SpA / 252 Spe / 4 HP
Moves:
-Tail Glow
-Ice Beam
-Scald
-Heal Bell/Dazzling Gleam
Tail Glow raises SpAtk by 3 stages (x2.5). Scald is for STAB while also being powered by Life Orb and Tail Glow. Thus, making Scald have a BP of 300. Ice Beam is for coverage and Heal Bell is also to heal your team's status conditions. You can also use Dazzling Gleam to have moves super-effective against more types while also hitting both opponents in a Double Battle.