If your best senki are lvl 40 4* (I will be able to evolve one soon), i.e. not terribly powerful, is there a point in doing the various conquest events? Normal is fine, hard is tricky and drops don't seem to be very good. Also, every time I've done a 15 stamina evolution materials, I've gotten almost lower returns than I would from the 5 stamina - just bad luck or is that commonly seen.