He pretty much formed his own grug club and clobbered people with it. Also for feudal and even modern Japanese standards Musashi was a giant of a man, that combined with big grug club will fuck up just about any katana he would have faced. You could also say he &ldquo;cheated&rdquo; in a way, but in those types of fights the only rule is to drop the other guy and keep yourself alive, which Musashi had no trouble at all in doing. 