The picture shown looks like the ear is what is damaged. I personally would not bandage it, I would keep it covered in ointment, but open to the air. Bandaging in many cases can actually seal bacteria in and increase chances of infection. Apply the ointment as necessary to keep it covered in that and moist. Sometimes letting it hurt keeps them from moving things too much while they heal, so that's the trade off in treating the pain. If he is not actively bleeding then aspirin would be OK, vet's usually prescribe meloxicam for pain. Will he drink if you dip his beak? I'm sure he's very sore, and probably will be for a while. You do need to keep him hydrated, so it is important to get fluids in him, and that may be a challenge. Tubing fluids might be better, you can get more in at one time and not have to do it as often, until he starts drinking on his own. You need to hydrate him before trying to tube food, if that's necessary, and fluids should be warm. Here are a couple of links to help:
https://www.backyardchickens.com/th...res-under-construction.1064392/#post-16201671
https://www.backyardchickens.com/threads/go-team-tube-feeding-updated-12-29-2019.805728/
While he's resting he may be more comfortable with some rolled up bath towels around him to help prop him up, maybe one under his neck for support. Experiment to see what works. If that stresses him out, then don't. Do everything slow and gentle, and talk to him soft and soothing while you do anything. If he flaps and struggles then you can wrap him like a burrito with a towel to help hold his wings, a helper is always a plus. Even really awful injuries are often survivable as long as infection doesn't set in and supportive care is adequate. How much time and effort is always up the the human doing it. Best of luck with him.
https://www.backyardchickens.com/th...res-under-construction.1064392/#post-16201671
https://www.backyardchickens.com/threads/go-team-tube-feeding-updated-12-29-2019.805728/
While he's resting he may be more comfortable with some rolled up bath towels around him to help prop him up, maybe one under his neck for support. Experiment to see what works. If that stresses him out, then don't. Do everything slow and gentle, and talk to him soft and soothing while you do anything. If he flaps and struggles then you can wrap him like a burrito with a towel to help hold his wings, a helper is always a plus. Even really awful injuries are often survivable as long as infection doesn't set in and supportive care is adequate. How much time and effort is always up the the human doing it. Best of luck with him.