I haven’t participated, but looking over the rules the only thing that strikes me as odd is the challenger deciding the battle format. Wouldn’t that, to some extent, skew the battle into the challenger’s favor? Like they could choose whatever battle format their character works best in, while the challenged just kinda has to deal with it, even if they’re put at an incredible disadvantage. But, that’s just from a quick glance at the rules; I have 0 experience with the dojo itself, so take what I say with a grain of salt.