The purpose is to breed demons with compatible mortals. The resulting half breeds often retain some super natural powers while being more suited to living on this plane permanently.
Cool, just stumbled across this one, presume its a possible followup to Dark Alter. There's only the one page despite being page 02?
My theory - the demons are being used just as much as she is and they don't like seeing their offspring being enslaved by the people running the ritual, so he's helping her to escape in the hope her and her child can be free.
Maybe in the future the child will return to destroy the cult.
