Honestly I've received enough through the stamina events to do 6 ninjas. There's really no changed needed to it. The only expensive add up is the mood scrolls, they just don't drop anywhere or receive that hardly at all for anything. I've received 1 mood scroll and i believe that was for receiving 1st in the sage battlefield ranking. But personally theres nothing wrong with the system just wish the scrolls would drop at a higher rate somewhere or be part of an event as well alongside the meat*.