The bullet didn't hit anything exceptionally vital, but the shock to neighboring organs and the risk of lethal infection from a punctured digestive tract are keeping him on the critical list.
The acid damage to his face is severe, but there's a good chance he'll regain at least partial sight. There will be scarring. The rest of the demon damage was standard slashing - given time and physical therapy, his muscles will recover.
This being Whistler's Point, "we were attacked by a gang and I don't really remember their faces" goes over pretty smoothly. Madison should get herself stitched up as well, as she only healed the first hour's worth of that damage.
The doctor on the case comments that it is remarkable he survived surgery, given how much blood he had lost. If they can keep infection under control, he should make it.