Maybe you can still sync the Wii Remote –
but this does not look easy. Getting a GC controller is
MUCH easier.
Instead of decrypting and re-encrypting a NAND image with the bricked console's keys (or using
this for creating a new image) to flash it onto the NAND:
Please try other things before. Flashing anything other than a known-good image on a Wii without BootMii@boot2 is very dangerous. You will need at least the console unique keys to create an image.
Once you can control Priiloader, there is the possibility to run Syscheck (which will most likely provide helpful information) and a WAD manager to install/repair things.