>>37451694I get that, but the only time Sakurai actually took liberty in a Pokémon moveset was, ironically enough, Incineroar, he’s the only Pokémon character that performs a move not in the Pokémon games, but even then it’s still somewhat true to the concept, as he did do that in the anime and he’s capable of creating a wrestling ring out of nothing in his Z-move.
Greninja’s kunais are also from the anime when he performs cut, while Mewtwo’s vortex is confusion, both of which Pokémon are also capable of performing across media in the same fashion they do in Smash, the only thing Decidueye does as a ghost type across all media is phasing, you can’t justify him doing any other ghostly things like you can with the others, especially since his ghost typing isn’t highlighted at all anywhere.
