If i could only find a cheap way to make gengetsu 3*, I'd propably use him all the time- unfortunately I'm only slowly gathering the frags from myoboku wheel. Even now Im using his 2* version from time to time on sage, and I'm often able to kill a fire type ninja in first round, provided gengetsu c*e mystery and I combo on that ninja. As far as I know, he currently has the highest ninjutsu growth in the game and his ingame animations are really pleasant to watch. The only downside is that he's * squishy. Not top tier meta ninja, but its just so satisfying to watch a 10x 300 hit and then ~8k crit on a fire ninja.