As a mod, as you asked for help figuring it out, I'd say: you do not like the guy? Block him and forget him. As simple as that.
He's free to mute, unmute, follow and unfollow whoever he feels like.
(I hope I'm getting this straight, the whole thing is pretty weird)
QOTO: Question Others to Teach Ourselves. A STEM-oriented instance.
No hate, No censorship. Be kind, be respectful
We federate with all servers: we don't block any servers.