User blog comment:DerpyDoodle/Mewtwo's Moveset/@comment-8182065-20141028230128

I feel (and hope) that they'll go with Mega Mewtwo Y for the Final Smash. And I do hope they don't just give him a standard transformation FS. I really hope that instead of battling as Mewtwo Y for a short time, he does a trapping Final Smash; first traps opponents close to him with Telekinesis, then mega evolves and performs Psystrike.

Its a Mewtwo exclusive move, so I'd be surprised if it wasn't used in some fashion.