Frostwraith
The Demon King
it would be funny and epic to have some of his attacks being the spoon, they could be stronger than his tail attacks or other physical attacks that are kinda weak. and in Pokémon, Psychic-types aren't usually famous for their physical prowess, with a few exceptions like Metagross and Gallade.
that said, they could rework Mewtwo's moveset to include newer generation moves, his signature Psystrike starting in Black and White, and they could put the spoon from the manga for stronger physical attacks.
also of note is that, just because it's from the manga, it doesn't mean it can't be in SSB4. in the Pokémon games, there's a TwistedSpoon item that boosts Psychic-type attacks, so it could derive from that too. also reminds me of Kadabra and Alakazam...
that said, they could rework Mewtwo's moveset to include newer generation moves, his signature Psystrike starting in Black and White, and they could put the spoon from the manga for stronger physical attacks.
also of note is that, just because it's from the manga, it doesn't mean it can't be in SSB4. in the Pokémon games, there's a TwistedSpoon item that boosts Psychic-type attacks, so it could derive from that too. also reminds me of Kadabra and Alakazam...