Timeless said:
Swagger
Psych Up
U-Turn
Aura Sphere
Ability: Regenerator
EV/IV: Perfect Attack + Speed
So, I'm guessing the strategy here is to use Swagger to confuse and boost the opponent's attack by 2 stages, then use psych up in anticipation of a switch?
Well, couple things. One, you're going to have to set up on a wall. Mienshao is very fragile and will not hold its own against an attacker. You also have no guarantee that the Pokemon you confuse will stay in for you to use Psych Up, so that's going to be a shaky problem that you run into. The EVs look good, and the set itself works in theory. You will want to watch out for Will-o-Wisp though. Burn will cut your attack power and make the boost seem like not such a good idea after all. Plus, if you're setting up on a wall, it may be hard to break while Mienshao is very fragile and (once again) can suffer from burn or be effectively crippled by another status ailment.
Replace Aura Sphere with another Fighting-type move because Aura Sphere is special. If you're going to use Psych Up to boost your attack stat, you want something that uses your attack stat, not your Special Attack stat. I recommend Hi Jump Kick if you are not afraid of having a ghost switch into you or the accuracy. It's extremely powerful otherwise and you will mow down practically any Pokemon with a two stage boost. The set doesn't seem extremely practical, but it's something that you may be able to try out for a late-game sweep. Mienshao has a good speed, but is not by any means un-trumpable.