just put the mod in the content folder (wiiu/games/smash/content) make sure you have smash updated. it should work depending if the mod pack is already packed but if it isn't then you would need to set up sm4shexplorer
you can check if any of the sd cards works with smash (take a screen shot) or mii maker (save a QR code). If none of your sd cards work with those then you might have a broken reader.
@SylverReZ, I also recall watching a video of some failed games with their own crypto currency or smth like that, lemme link it to you (it's in spanish tho)
Glad to hear people realise that NFTs aren't worth it these days. They realise that they're JPEGs hosted on a file-hosting site like AWS or Google Drive.