This is a good code, but it should be used much after this.Here is how I have done that:
First of all: The cheat is from @GoldCobra
It changes the progress bar. You will need to this one or two times.
The code is: 12CDB1A4 5F5E0FF
This will change the progress bar to 99999999. After that you play some round something online. After you have done this, it will add 99999999 and you should be level 50. (If not: Do it again.) I don't know if this code is correct because I can't access my computer right now. Edit me if the code is wrong. And I don't know if this will ban you. It didn't banned me (yet). It should work on all levels but I don't know. I've tested it with TCPGecko only so I don't know if other methods are working.
USE THIS AT YOUR OWN RISK!
I'm not responsible if you're banned!
I have realized that Money/Level/SeaSnail/Weapon/Gears hacks and Cafiine {text editing, night and day} All require editing the save, which means that they sort of stick, unlike Octohax and Colorhax, which are clientside and turn off after you restart your wii u. Hopefully those SHOULD be safe....I might try it.
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...People agree...right?