As far as I am aware there was no story plot associated with Korax i.e. who was Korax, why was he a ghoul, why was he dire charmed and so on? Perhaps this is an area that could be expanded upon. (I note in the novels Korak had some history with Candlekeep).
Another potential consideration is that instead of being dire charmed, what about if Korax is simply friendly dependent upon the dialogue options chosen, then may potentially betray the party at a certain point?
Another potential consideration is that instead of being dire charmed, what about if Korax is simply friendly dependent upon the dialogue options chosen, then may potentially betray the party at a certain point?