I'm new to this forum and new to catfishes, but I have 3 little raphaels myself. And, I don't like to give up on fishes either!
First, if you are going to try to save this fish, you have to give him some peace. Section off the treatment tank or better yet, get another 10 gallon just for his recovery. I can't imagine any fish healing well while being picked at by a tankmate, it just sounds really stressful! Give him a hiding place in the hospital tank, in addition to separating him from the convict. You won't be able to check on him as well but isn't it stressful for him to be out in the open? Everything I had read says raphaels like to hole up during daylight.
I don't see a picture of the wound, so I wouldn't make any predictions. I've known of some very serious wounds on goldfish and koi to heal, though. If this were a carp I'd probably apply a topical antibiotic -- but I expect the raphael is not accustomed to handling, that you're not used to handling the raphael, and I'm pretty sure the raphael is stressed about to the max by the initial attack and the recent pestering. So you're probably better to leave it alone. Add some Melafix per bottle directions. It's not much of an antibiotic but it DOES help healing considerably. Provide excellent filtration, don't let any ammonia or nitrite accumulate and do small frequent changes to keep the nitrates low as well. Provide hiding places and let the fish use them.
Start thinking now about where the fish will live if he does heal up. I don't know if fish have that sort of memory, to hide out if returned to the tank where this happened; but I would definitely worry about something similar happening again since whoever the agressor was, has shown him/herself quite capable of taking on a thorny raphael. He needs very peaceful accomodations to heal up in, but he will also need safe accomodations when he's better. Plenty of hidey holes, no raphael-choming tankmates.