Darkness of Melbourne
A force of Angels who sided with Lucifer in the great war. They were forced down to Earth, and massacred in a great battle, but evil, as always, survived.
It is unknown how many of the Fallen survived the initial war, but many have existed on the earth ever since, corrupting humanity, offering the path to sin, and manipulating the Earth to their own ends ever since, always working towards their end game.
Armageddon and the war against Heaven.