Wow this thing got fucking trolled.
The best you probably should pull with is something like... this maybe.
Archaeos @ Expert Belt / Flying Gem
ability: *BARF*
nature: Jolly
evs: 252 Atk / 4 Def / 252 Spe
ivs: 29 HP (or whatever will allow you to step into Stealth Rock 4 times with 1 HP remaining)
- Stone Edge / Rock Slide
- Earthquake
- Endeavor
- Head Smash / Taunt / Acrobat / Quick Attack
Yeah, this thing is depressing. I probably wouldn't touch it in OU, aside from Swords Dance and you -need- to force a switch to make that one work well, but this is about the closest I'd get to it. You obviously don't want Life Orb. Don't even think about it. Take advantage of Stealth Rock. Once you step into Stealth Rock twice, you should still have enough enough HP to keep out of Faint-Hearted (and I hint at "should"). So this gives Archeos a maximum of two turns of damaging what he can. With Taunt, you can at least force Skarmory to use Brave Bird if it switches in. If you see Nattorei or anything that resembles a priority sweeper, get the fuck out. After you step into Stealth Rock 4 times, you should be left with 1 HP, which in this case just Endeavor. You can use Quick Attack to finish the Pokemon off. Sadly, it can't finish off Steel-types (there's no way in hell), so at best it kills off a sweeper. Head Smash is the closest you can get to suicide: it hits just about the same as Rock Slide does before Faint Heart activates.
Choice Band:
- Rock Slide / Stone Edge
- Earthquake
- Dragon Claw
- Head Smash
Okay I lied, I might consider this set. Screw U-turn really unless you can keep Stealth Rock out of the way. Easier said than done perhaps. Head Smash for your psuedo-Explosion.
Honestly, this thing disappoints me to no end. Faint Heart was a real troll ability. Granted, if you can keep Stealth Rock off the field and dodge priority (hint: it's pretty easy to predict priority), Archaeos can be okay. It's just pathetic how your best STABs are left to moves that can't afford to miss or rely on not holding an item.
I think this thing will be lucky to be UU. Pity, Gamefreak really needs to learn how to make nerfs properly. You know, ones that don't completely cripple the hell out of a Pokemon at such a health. If it was only <25%, in which case it might've been okay, but it's still a dollar short in sweeping. Maybe Aero does have it good after all.