The only way to deal with a bully is punch him in the nose.
That approach with Aurel quickly escalates to vulgarities and childish name calling as his response. (in broken English to make it worse)
I think ignoring him is the best way to get results. I propose that no one (except Charles) respond to Aurel in the upcoming month of January. If things don't get better, we will extend it for another month until he does.