Well, this will probably be your best shot:
Dragonite (M/F) @ Leftovers
EVs: 4 HP / 252 SAtk / 252 Spd
Modest Nature (+SAtk, -Atk)
- Roost/Rain Dance
Dragonite doesn't really need STAB in this Case. The 100% accuracy Thunder and Hurricane (120 base power) make up for that easily.