Im looking for a device that allows me to easily plug in my wiikey fusion to my game cube without the advanced soldering. If nobody has one, I could always use some tricks to making this as easy as possible.
No. Something that you just plug right into the gamecube from the wiikey does not exist. Use a breakout board (check here and scroll down to the picture for the kind of breakout board you need) and the bottom of the DD plug. That is as easy as it is going to get.