You may not have much time, but there's a relatively simple option with the cat. I've used it multiple times (animal foster care - works on dogs and horses, too. Maybe on kids ... but don't tell anyone I said that).
Clean your hands (no soap), lick one hand and pat the cat with that hand. Around the cheek/whiskers is best, then the ears to tail wipe. Use the other hand and do it again. Do this twice daily, and the smells you mark the cat with make him part of your clowder. Also, give him a piece of (well-used) clothing of yours (not, not smalls) to sleep on. Cat's have an amazing sense of smell.
Another thing to do - often - is the slow blink when he's looking at you. It's a signal of 'I'm not going to harm you, I'm calm and trustworthy'. However, if you do this during an altercation, it won't work. Things must be calm enough for him to notice it. He must trust that when you do that, no harm is going to come to him.
And an extra that works even if the others take a long, long time, is play therapy. Play the games where he chases a bit of paper on a string, wear him out (before meals; remember, it's chase, catch, kill, eat - make him work for his dinner). Best before meals, but can be used at anytime to distract from a confrontation.
Luck! I think his attitude is one of being fearful, not aggressive. He can be redeemed.