Hi everyone, I got a solution for you all, eve though I'm doing everything through my old Nintento wii (Not a WiiU). Here is what you should do on USB Loader GX:
Video Mode - Force NTSC
VIDTV - OFF
Ocarina - OFF
IOS...
just so everyone is aware, if you download and install a 3ds rom via liberashop on tinfoil, it comes with the citra core for retroarch. completely for free