MonoWater Rain Team?

Swampert-Mega @ Swampertite
Ability: Swift Swim
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Waterfall
- Earthquake
- Ice Punch
- Power-Up Punch

Volcanion @ Choice Specs
Ability: Water Absorb
EVs: 252 HP / 252 SpA / 4 Spe
Modest Nature
IVs: 0 Atk
- Steam Eruption
- Fire Blast
- Sludge Bomb
- Earth Power

Politoed @ Damp Rock
Ability: Drizzle
EVs: 248 HP / 164 SpD / 96 Spe
Calm Nature
IVs: 0 Atk
- Encore
- Scald
- Rest
- Toxic

Manaphy @ Leftovers
Ability: Hydration
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Rain Dance
- Tail Glow
- Scald
- Energy Ball

Azumarill @ Sitrus Berry
Ability: Huge Power
EVs: 92 HP / 252 Atk / 164 Spe
Adamant Nature
- Aqua Jet
- Waterfall
- Play Rough
- Belly Drum

Rotom-Wash @ Leftovers
Ability: Levitate
EVs: 248 HP / 252 Def / 8 Spe
Bold Nature
IVs: 0 Atk
- Will-O-Wisp
- Pain Split
- Volt Switch
- Hydro Pump