I've now Completed over 100 fights in the spirit  keep all above level 12 and not had a single superior potion drop.  I can't progress on the mission.  If this is just rng then it's rubbish.  What are the odds?  All I get is basic potions with the ocassinal tonic or greater.  This is unplayable as there is not enough enegry to be able to rank up a legendary at these rates.  Surely this is broken?  I have screen shottes the last 30 fights and that's just a quarter of what I've done