Board Thread:Speculation House/@comment-3146930-20160522215152/@comment-3146930-20160522222705

That could actually add a bit of evidence really, not counting the opening (most of the stuff in the opening doesn't actually happen anyway). But if the idea for the maidens was introduced at some point in Volume 2, the same volume that Raven was introduced in and the first time we see the vortex outside of an opening. Then when we finally find out what the maidens are, they use that same effect when Amber has her powers stolen.