The biggest issue with adding a Youkai Watch character is that the series is like one year odl! It could wind up a flash-in-the-pan series that declines steeply a year from now. Not making a prdiction here, but making a point: the franchise is young and unproven and plopping a character from it into Smash Bros could look really silly if a year from now Youkai Watch begins a steady death next year.