Psystrike is Mewtwo's Final Smash in Super Smash Bros. Global Apocalypse. It can be considered a stronger version of Psyshock. Mewtwo touches the ground with finger, creating a shockwave of psychic energy that destroys anything in its path, dealing explosions of psychic energy to any target it hits. It is very powerful in both terms knockback and damage and is very hard to avoid. The move is explained with more details here.
Pokémon Generation V