If it were me, I’d have him captured and put to sleep. I LOVE cats, I have 3, all of which were rescues, but from a functional stand point, he will never be anyone’s pet, he is not living a good life, he is sick and mean. Its probably best for the animal to help him not suffer any more. And, like everyone said, it will be good to control any sort of disease he might have.
I read this last night and thought about it, and went to bed. I had this crazy nightmare where I was walking to work (not something we do in Texas lol) and I rescued all these cats along the way. When I got home with the new cats, there were 2 more cats, brother and sister, that were new. The brother (both of which are comically HUGE/fat cats) and purple (go fig) starts trying to swat at me and hiss and growl at me. After that, all the cats turn feral and demented and have to be stored in reptile terrariums, where they get even stranger and start drooling among other things. o.O