Those with the power of God existed, a millennia ago.
And their mission is to kill "Akuma", the devils hiding in the darkness.
Earl of Millenium is the leader of the Akuma, whose goal is to destroy "Innocence",
Using the only thing able to defeat the Earl and his army; the ancient Great Flood.
The Black order use sorcerers to defeat the Akuma, those with the ability to forgo Innocence.