Osawari was fun at first. However, I just farmed the last Forest stage for multiple copies of Izanai and I had enough healing to basically steamroll anything. The only thing I haven't beaten is the super hard stage because wave 4 has a guy with max defense (each hit was doing 10 damage). Had I been paying better attention I could have kept my combo up better to beat that guy, but I had been fighting for over 2 hours and my eyes were glazing over.