Holy Energy might work. I don't think making the Catch(Pure Mortals) would quite fit, though. Basically, the way I'm seeing it is that Bear has been physically transformed into something more than human by his prolonged exposure to angelic power. Have you ever read the Keys to the Kingdom series? (Spoilers for that series ahead, so proceed with caution). You know Arthur becomes more like a Denizen of the House and less human the more he uses House magic? Same thing. I think having Holy Energy be the catch would be good. It'd basically mean that the only things that could blow through the defenses given to him by God is a stronger power granted by God, which makes sense. That would, however, probably be a +0 Catch, since there aren't many people running around tossing Soulfire and the power of the True Faith.