what to do with my injured roo?

as a gift grandaughter gave us 4 roos and 4 hens.. all chicks so she didn't know any better.. well they all got along great.. 9 mos now..till it snowed and they were cooped up inside.. hubby went in to say goodnight and came running back with a roo totally bloody.. not opening eyes.. we thought he was a goner..he had blood frozen all over his saddle, face, just really horrific.. so we cleaned him up and found he did still have eyes. they were just frozen over with blood.. so he has recouped in a large dog cage.. well hubby went back out and found the head roo in a corner and a hen all fluffed in another corner.. so we brought them in too..every one is now fine but we like the head roo and put him back with his 4 ladies and put the other 2 roos who took over, into a bachelor pad we had built just for this purpose.. i tried to put my healed up roo back out.. it has been 5 days now and they all attack him.. it was all i could do to get him back into my arms.. with flailing wings and feet all over the place.. so now i have a great gentle roo in my family room.. i hate to keep him alone in a dog kennel till spring (late april here) until i can build him his own place with a few new female chicks ... he is a big RIR .. any suggestions? he also crows all day.. so i know he must be lonely..we take him out in the evening and feed him treats,, kale, scratch etc.. and he is sweet as can be but he isn't one for just sitting. he would prefer to fly all over the house and we can't have that.. the house is new and the carpets would end up a mess...i want to keep him .. just not sure how to, till spring

edited.. we haven't the heart to kill the other 2 who caused this mess.... and no one wants them for free