Weezing is actually quite potent, and often overlooked...
Weezing @ Damp Rock
Ability: Levitate
Shiny: Yes
EVs: 80 HP / 252 SpA / 4 SpD / 172 Spe
Modest Nature
IVs: 0 Atk
- Rain Dance
- Thunder
- Will-O-Wisp
- Sludge Wave
This set allows Weezing to become an offensive rain-setter, capable of inflicting paralysis, burn, and poison, severely crippling an opponent's team to pave the way for more powerful rain sweepers. Thunder allows Weezing to take care of opposing bulky waters and things that would otherwise destroy it, Will-O-Wisp takes care of Ferrothorn and other difficult-to-handle things, and Sludge Wave provides STAB that it can use to barrel its way through bulky Grass-types such as Chesnaught that would ordinarily be quite annoying for a Rain-team to face.