Okay /vp/, I have a task or you. Maractus has pretty low stats and is a one-stage, forgettable mon. (Don't give me that look, it's just the way it is.) So if Generation VIII ends up doing them, it's pretty much a shoe-in for a cross-gen evolution.
I task you with coming up with some kind of concept for its evolution beyond 'it just gets bigger'. it should stick with what it's already doing -- Maactus's "thing" is that it's a happy, dancing, Mexican maraca cactus. So I dunno, something more fun, less spiky.