Psystrike

Psystrike is Mewtwo's Final Smash in Super Smash Bros. for Nintendo 3DS / Wii U and Super Smash Bros. Ultimate. Upon activating Psystrike, Mewtwo Mega Evolves into Mega Mewtwo Y, then fires a large ball of psychic energy across the screen in the direction Mewtwo is facing, stunning any opponents in its path. The stunned opponents then take heavy damage and are launched away as Mewtwo returns to normal. Opponents can be stunned even if they are in the air.

Background information
In the Pokémon series, Psystrike is a Psychic-type move learned by Mewtwo at level 100, and it is Mewtwo's signature move as of Generation V.