Nintendo should have made Bayonetta a character in Smash. Give her similar moves to the ones in the game (at least visually)
It should have been a free day1 DLC that at the same time hints at Bayonetta2 being a WiiU game. Like having a third of the main menu dedicated to advertising of this DLC character the first 3 times you start the game. (So she does not get oveooked i the huge rooster)
That would have helped. It would be practically free advertising.