Yeah, 10's since they have the best rates, but I need a bunch and it seems like every other run I get a mat instead of a gem. And a bunch ofMana PrismsSilver EXP. Since all my servants are now max level, my next main goal is to get everyone's skills to 4/4/4, since they only use gems (except fucking avengers). The problem is that there are so many low tier assassins and casters that they expended all my stores.