Nigh Invulnerability/Fan Works

Paul in With Strings Attached. He needs it, since he's holding a shitload of energy inside him and would explode quite thoroughly without it. He is literally Made of Diamond; his hair, nails, and teeth are either diamond or diamond-like. Presumably his bones are diamond too. He has so far been invulnerable to most everything, including dragon fire, but he has no resistance to intangible things like wraiths, and the Hunter's BFS once cut him just enough to draw blood.