Hello, welcome to the site. I’m really sorry this happened to your flock. Your rooster may be in shock still. It’s important to try to treat him for that first (and quickly). Keep him somewhere warm, dark and quiet. In this case get him somewhere safe, also where he isn’t at risk for attack again. You will need to try to get to drink some water with electrolytes and a bit of sugar or honey mixed in. A homemade solution is easy to make, Gatorade or pedialyte (room temp) will also work. Gently dip his beak into the mix or drip some on to his beak so it dribbles down into the crevices for him to intake the drops.
A soft material like coban is suitable for wrapping wrings, yes, but sometimes the easiest thing to do is limit their activity as much as possible, especially if he is in shock. You may very gently feel along his wing to assess for dislocation or breaks when he pulls out of shock, that would help you know how/where to wrap or splint his wing. Keep in mind he may not have any breaks and may just need to hold it where it is comfortable for him until it heals.
As for his leg being hurt, again just limit his activity until he pulls out of shock. Later you can assess for any breaks, sprains, etc.
You will however need to check him over for any open wounds. Check very thoroughly under all his feathers. Any wounds will need flushed with saline or a wound spray then slathered in a triple antibiotic ointment
without pain relief in it. If he has any large or concerning wounds, please post pictures of them for further help.
Post number 7 on this thread has a splinting manual for avian fractures provided by
@Eggcessive should you need to wrap/splint/sling anything.
https://www.backyardchickens.com/threads/hen-limping-with-curled-toes.1647100/#post-28205205
The manual is a really good resource, but again you may need to just let him rest. Sometimes splinting can cause more harm than good if it isn’t needed or is done incorrectly.
