https://www.youtube.com/watch?v=qAFJhtJlIBw
During a Pokkén Tournament livestream, it was revealed that they would be adding a new boss type character in the form of Dark Mewtwo.
It’s unclear whether or not this new form for Mewtwo will be exclusive to Pokkén Tournament or if we’ll see him in future Pokémon titles.
Pokkén Tournament is set to release sometime next year for the Wii U, worldwide.