you are pannicking again. I told you....DEEP breaths....TIME.....

It may well take longer. And I do recall very similar fears with miss Olivia. Which cat of yours would give him a whollop or 2? He may need some cat to show him to back off. With the soft claws in place they aren't going to damage each other too much (yes of course they can bite, but it might only take one little nip to have him back down)

Was he a recent neuter? Maybe he still has some hormones racing in his system. That is very possible.

It is nice to know that he can have a potential home if it never works out, but I truthfully think the cats just need to show him how to act.