So I just caught this Mewtwo: Hasty 31 / 25 / 15 / 31 / 30 / 31
Now, you may think, oh Jebus, just toss that, bad Def and not Perfect Atk. However, with Hasty, its Def isn't gonna be great anyway, so bad Def is acceptable (not ideal, but usable). As for the Atk, 6 less Atk at Level 100 (assuming MM2X) is only a 1.2% difference. But the real reason I like this Mewtwo is its Hidden Power, which is the only useful Hidden Power for Mewtwo, HP Steel. It hits Diancie harder than anything else Mewtwo can do. Also, Hasty Mewtwo is useable for both MM2X and MM2Y (if we get a Low Kick tutor in ORAS), MM2Y gets a +40 Atk Boost and Low Kick hits hard in Ubers.
tl;dr, caught a cool mewtwo yay