Kolorado should at least return as a temporary adventuring partner. He practically made Chapter 5 in PM1. --- If Waluigi ever gets a game, it'd better be about him killing Wakoopas and rescuing Watoads as he makes his way to save Wapeach from Wabowser. - GradyHoover
Or a whole game named Paper Kolorado, where you must try and fail to get the biggest treasures of the world. The final boss would be Wario for obvious reasons. And Scrooge McDuck should fit somewhere in there... --- I can't beat Super Mario Bros.