Maximum Ride: The Demon Experiment

The Flock: The Angels. The others: The Demons.
A new company makes itself known and threatens to destroy all who are not worthy of living. By use of ancient rituals, they plan to sacrifce one of the two, the Angels or the Demons. Question here, which is it? And who's side are the Demons on? Can Max and the gang save the world?
(AN: Not rlly set after any of the books. Probably before Fang if you think about it.)