this captain i'm complaining about just recently got his commands and we've flown couple of times and his attitudes worsen by the days
hmmm, these things are always a matter of perception... maybe he is absolutely not aware how he affects his colleagues.
I have seen that before with new captains, ironically with some guys who complained a lot about their captains when they were F/Os...
I would try to talk to him and see how far you get. Never easy for an F/O.
Good luck !