I'm planning on buying a new Wii U, but i want to confirm this first. Can I plug in one flash drive on my old Wii U, copy my save game, and then use that flash drive to transfer it to the other? If not, can I use the 3ds transfer to take my save file from my old Wii U to the 3ds, then transfer it to the new Wii U? If I can do that, is there an explanation for the 3ds changing the key from one wii u to another? Thanks!