here is one thing i never got. maybe i just missed something. why doesnt mystic gohan ever think to ascent to super saiyan from that original mystic state? or even super saiyan 2? that being out of the way, i'd say mystic gohan slightly. goku doesnt totally handle fat buu, or he would have ended it right there and mystic gohan would never have needed to be awoken. whereas, super buu, whom is presumably stronger then fat buu, can't hold a candle to mystic gohan. goku does hold super saiyan 3 for a while fighting kid buu, but keep in mind, half that fight he was struggling just to keep his power up, and as soon as he lost it, he was totally drained. he wouldnt be at 100% if he were to attempt to sustain super saiyan 3 through the whole fight. whereas mystic gohan keeps his power no problem, as it acts at the time, as more or less his base power.