Originally Posted by Fat Cobraroll
Mewtwo @ Choice Specs/Life Orb
Leaf Storm/Psycho Boost
Close Combat/Superpower/Hammer Arm/Recover(?)
I can imagine this hurting a thing or two. Except from Sturdy Shedinja, that is. You might want Stealth Rock on the field for that.
Interesting set. I think you're using the wrong item on it, though. You'll want to change your moves around a lot so you shouldn't be using Choice Specs and Life Orb will kill you pretty fast. I suggest using Lum Berry or Leftovers like most Pokemon in Hackmons run. Life Orb is usually an inferior item on most things.
I suggest using:
Mewtwo @ Lum Berry/Leftovers
Psycho Boost is your main STAB, V-create boosts your Defense, Special Defense, and Speed stat which is nice. Overheat boosts your Special Attack just like Psycho Boost and grants you extra special attacking coverage. Recover heals you up while you're boosting. Magic Coat might be worth using in one of these slots to block Spores (especially Prankster Spore's!) and prevent Pokemon from phazing you.
Also, the OP didn't say it, but in Balanced Hackmons OHKO moves and Wonder Guard are banned.