It would be funny, the turn I make an offensive against Pythium I get invaded by Pangea.
The problem is we have an NAP 3.
So I advise all other nations to be wary of the dealbreaker Pangea, don't feel like your word is binding. Pangea obviously don't feel it needs to honor its end.
Atlantis seems defeated at this point. As far as I know, they only hold two provinces, both of them forts, but I'm sieging one of them, and they haven't got a lot in the other fort as far as I can tell, so maybe it would be best to set them AI if the player has vanished again?