Hmmm, keep going back to the vague Gemworlder idea because I've always felt that Gemworld is a concept DC never explored as much as they should have (and because I have a soft spot for their fantasy comics like Amethyst and Demon Knights), but not sure how well that would work here.  But we'll see how things turn out, and at least I have fallbacks in case a Knight of Gemworld (or whatever) doesn't work out.