>>12592916This.
I seriously CANT see them booting Lucario. He's just way the hell too popular, and as such there's no "boot a character for the new rep" system confirmed, despite what people think. 1 game is not a pattern.
Also, as people are saying, Newtwo is a good choice as Mewtwo was barely out of Brawl anyways, and having a new form "refreshes" his relevance, so-to-speak.
The one thing I would emphasis about fixing Mewtwo is speed. Speed, speed, speed. Aside from the fact that it's critical in fighting games, Mewtwo is specifically fast as fuck in everything he's in. I'd honestly take that over being a heavy weight.
Also, I imagine his down B might be his transformation move for his second form.....
Aside from that, I love your ideas, brother.