Another good thing in the rain is the Volt-Turn stradegy. You could have a Choice Band Scizor and a Choice Scarf Rotom-W. Rotom could also have Thunder in case you want to predict they're going to use a fire move and instead hit them with a 180 BP never missing Electric move. Hydro Pump is also an option if they're resistant to Electric moves. Scizor can also be a little different. You could use the other common stradegy with Scizor which is Technician and Priority abuse.
4 HP/252 Atk/252 Spd
@Choice Band/Flying Gem
The Flying Gem moveset allows more diversity, however, the Choice Band set allows more power.