Got 3 demiatma from each of 5 of the 6 zones so far. But for some reason Shaaloani has taken it upon itself to be the bane of my existence. Have now done 76 straight fates there (ranking the zone up from absolute zero to max rank 4 - plus an additional 10 fates on top of that) - and not a single demiatma from that zone had dropped for me. So when people say it's just a case of mathematical probability and the more you do, the likelier it is you'll get them - I can honestly respond with "Meh - kinda nope."