User blog comment:Xilinoc/Ch. 610 - Mausoleum of Skulls/@comment-25891035-20141218194655/@comment-25407216-20141218231936

Call me crazy, but I think that the fifth SWP might be Orihime. She's the only character left with powers we have NO proper explanation for ("the hougyoku and Ichigo's powers awakened some sort of random hypothetically-unbeatable power in her" is a pretty cruddy explanation on its own which isn't like Kubo-sensei, who has a tendency to plan things hundreds of chapters in advance), so that's something which still has to be revealed, and I'd guess it's likely to turn out to be critical to the plot or we would probably have had an explanation several years ago. Bearing in mind the apparently "God-like" nature of her powers, this is the sort of thing nobody would expect but that is still strangely feasible, it would provide the potential for character development for Orihime, and it WOULD be kind of awesome if at least one of the SWPs was female.

Just my thoughts. :)