>>36202357Ok, so Shadow Ball WAS it's trademark move. It was it's trademark move because Psystrike didn't exist until Gen 5. It's the main signature move in Pokemon, and it's Mewtwo's final smash in Smash 4 and Ultimate.
As for movies, it's the same "ki blast" spam, I assume, that Vegeta pulls off. It's just a movie/anime thing.