Well, I thought he should have stayed. He was a great character, and wasn't a clone, so idk where they got the brilliant idea of kicking him out, when they know people are hating on jigglypuff, which should have been taken out in the first place. Point is, Mewtwo was awesome, even if he wasn't a legendary (because it doesn't make a flippin' difference), and was in SSB first. Squater's rights.