My new favorite Rain Abuser, this guy can wreck if played right.
Focus Sash allows for at least one Shell Smash Set up, ensuring the defense drop doesn't get you killed right away (Unless you've run into entry hazards, making him a no-go). Coupled with his Swift Swim ability, his speed goes insanely higher than your average sea turtle (or any turtle for that matter). Doubling his decent 340 Attack total, you're given Edge-Quake coverage along with a Rain-boosted, STAB priority move to help you get the drop on those annoying Mach Punchers, as well as most Choice Scarfed Pokemon in its tier. It should let you clean up at least a couple of the opponents Pokemon, with the only major counters being Entry Hazards, Priority Abusers, and some Decent power Grass-Type Walls (Virizion -_-) Note that this set ONLY functions in a RAIN TEAM. This is straight-forward Hyper Offense in an unprecedented strategy.
Carracosta @ (Focus Sash)

Trait: Swift Swim
EVs: 24 HP / 232 Atk / 252 Speed
Adamant Nature (+Atk, -SAtk)
- Aqua Jet
- Earthquake
- Shell Smash
- Stone Edge