This includes my wins, loses, everything that is saved after a finished For Glory match. I do not however want any data that has to do with the Wii U itself, just data for the game that is stored on the Wii U.
2 Answers
In Super Smash Brothers for Wii U (and 3DS) there is only the nuclear option, which is going into system settings and deleting game data. This would wipe all earned characters, stages, everything.
You cannot erase For Glory data unless you also erase everything else.