The butt-wiggle and pounce sound like play-time! (And he IS a big cat!)

If there is real screeching, ears FLAT back, howling and blood - THEN that is aggression.

I think he is just a happy guy and likes to play - and wonders what is wrong with everyone else!

One cat at a time in one room...I guess he feels that is "his" room, and there is less of a problem there.

I think once one of the other cats draws the line and smacks him back, things will settle down.

Or - you could put him in his room and bring each cat in one at a time, supervised.

Might have to do the old dab-everyone-with-vanilla-extract trick!