Rain Castform @ Life Orb/Expert Belt
Trait: Forecast
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature (+SpA, -Atk)
- Rain Dance
- Weather Ball/Hydro Pump
- Thunder
- Ice Beam
Okay, 252 SpA EVs and a Modest Nature is pretty crucial with 70 Base SpA.
Rain Dance activates it's Rain forme, because that's what this set it for.
Hydro Pump is STAB, and has a bit more power than Weather Ball at the cost of some accuracy. While Weather Ball is a bit more reliable and full accuracy.
Thunder works well with Rain Dance because it gets full accuracy, and is powerful gives some coverage and a good chance of Paralyze.
Ice Beam rounds out the coverage by hitting Grass types and gives BoltBeam exept there's not Tbolt.
Sun Castform @ Life Orb/Expert Belt
Trait: Forecast
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature (+SpA, -Atk)
- Sunny Day
- Weather Ball/Fire Blast
- SolarBeam
- Hidden Power Rock/Ice Beam
Sunny Day powers up Fire Blast and gives Fire Blast STAB and gives Solarbeam a nocharge up turn.
Fire Blast is STAB because of Sunny Day, and gets a boost from the sun. Weather Ball is another option though because of the more reliability.
SolarBeam works well with Sunny Day, and in the lower tiers there shouldn't really be weather war. It also gets excellent coverage along with Fire Blast.
Hidden Power Rock hits Fire types for some decent damage, Ice Beam gives some further coverage.
Castform @ Life Orb/Expert Belt
Trait: Forecast
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature (+SpA, -Atk)
- Hail
- Blizzard
- Thunderbolt
- Hydro Pump
Hail gives it a nice attack in STAB Blizzard.
Blizzard is STAB and has full accucary because of Hail.
Thunderbolt hits Water types and has good coverage along with Blizzard.
Hydro Pump hits Fire types hard and gives some coverage.