<Snipped quote by Etcetera>
Quite a few. The wing could be indicative of a category, or an individual "mutation" or injury. Many light-based angelic entities also use barriers, but the one I'd gravitate towards first would be an erelim. Or perhaps a nephilim. It would probably be easiest to check it than muse over the different things it could be. Erelim aren't universally one-winged, but they have a higher rate of it than most that fit into the category of both barriers and light. Nephilim tend to be all sorts of classical element based, so one that's got powers of light isn't far fetched.
And the weakness of those? It seems that finding a particular material that they dislike would be too simple.