If you attempt to factory reset your Wii U and it has Cold Boot HaxChi (cbhc) installed, it’ll permanently brick your Wii U. This is because whatever Nintendo DS game that is assigned to cbhc is used to start the console into the home brewed environment. If you delete this file (which will read “don’t touch me”) or even move it off of the device, your console will be bricked. So it’s very important that you know if you’re running CBHC or not. You should also see what vWii hacks were performed, though I’m unaware of bricking issues due to factory resets (I could be wrong).