My GOODNESS that sore looks SOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO much better. It is amazing what clean water can do, eh?
All sounds like great news. I would keep him in hospital for at LEAST another week (2 if possible). I know all those water changes stink but the proof is in the pudding!! hopefully you are keeping his filter cycled.
He looks so much better.
Not trying to be a downer but please dont be hard on yourself if he still doesnt pull thru. That was a pretty sever injury, and with the pineconing could have been a number of issues. Hope hes not just rallying but honestly seems to be on the mend

. Are you doing any meds right now or just clean water? Id keep on a diet of Bloodworms 2-3X/week and flake/pellet every day in between. fast once a week.
Good job so far. Im realllly routing for you and the fish.
Just shows how resilient fish can be. He had a really nasty wound/infection. again. job well done. Be proud
Please keep us posted!
Cheers
*edit to add*
his scales probably wont grow back. that injury was very deep. It will likely be like a scar on his body. I still see some redness/irritation in that area from your pics. I would not move him until all the redness/irritation is gone. Maybe a few quick 5 min salt dips but nothing more( 1 tsp/gal for about 5-10 mins once a day/ every other day. dont go running out to buy aquarium salt for it tho. if you have some on hand not a terrible idea. Prob doesn't need it tho, really. He looks s zillion times better)
**edit AGAIN to add**
Id say it is safe to d o short dips in aquarium salt now that his swelling has gone down. If you do use salt dips, just make sure you pay attention to his pineconing. If any signs of pineconing stop aquarium salt dips stat.
im very happy for you both. HATE when the fish get sick!
cheers again.