I have 9 chickens who used to get along well until one of them, a red sex-link, started molting a few months ago. The other chickens started pecking at it. I noticed that it was bleeding, so I isolated it in a small coop in our garage for a few weeks until it healed and its feathers regrew. However, every time I try to put it back with the flock, multiple chickens attack it viciously. They even jump on its back and attack its comb. The comb became bloody and scabbed, so I had to remove it again. It can defend itself against one chicken, but about 5 different chickens attack it, often simultaneously. It is one of my favorite chickens and I hate to get rid of it. Any suggestions how to resolve the situation?