You know what would´ve been awesome? If they had put the former Fall Maiden´s soul into Penny.



Then again, that´d defeat the whole "no single person can hold on to this power forever" thing, since Penny would screw over Cinder, get the full Fall Maiden power and, as an artificial life form, could actually keep that power forever (well, as far as age is concerned).

Then she´d build more copies of herself which her soul could retreat into when her current body gets destroyed, catch the other four maidens and put their souls into one of these copies as well, and we´d have a nearly unstoppable army of Cyborg Maidens wreaking havoc. Mostly on Salem´s place, but still...