I agree! There has been times ppl that came over a lot was able to be around him without him going off on them but it’s rare! He has even slept in the bed with me and another person without any anger, he did lay across my chest asif he was keeping me to himself! Such odd behavior my baby boy! I’ve been reading about redirected aggression and that he’s not angry at me, I just got in the way. Makes me feel way better! If he ever makes progress, I’ll come back and update!! Thanks everyone!!As much as you would like friends and family to love your cat as much as you do, that just doesn’t work with some cats. I don’t think he is angry at visitors, I think he is extremely fearful. And unfortunately some fearful cats lash out. I really don't think you can change his fearfulness so your only option is to continue to put him in a separate room when visitors come. I would make sure though that each you do this that you leave some special treat in the room with him so he begins to connect strangers with good food. But I would not let him out or visit him until everyone is gone.
If you at some point have someone move it they will need to stay as far away from the cat as possible and ignore him completely until he begins to calm down and accept them. This could take weeks or months.