The Laws of Magic
Other Names and Titles: The Betrayer, The Dark One, Father of Monsters, Demonlord, Bane, Anathema, and many others
Domains: Evil, Corruption, Betrayal, Murder, Theft
Relatively little is known of The Dark One, given how important he is to the history of the world, because Arcanos, the God King purposefully wiped out his name, symbol, and all but the broadest information about his deeds.
What is known is that the Betrayer deceived and betrayed the other gods of the Pantheon to steal their power and incarnate in the world. He used his powers to create demons and other abominations. Seeing the damage he was doing, the other gods pooled their resources to allow Arcanos, the God King to also take physical form in the world, to preserve the world, particularly humanity, the gods’ favored creation.
With the help of humans and the powers the other gods granted him, Arcanos, the God King defeated The Betrayer, killing him, and binding his corpse and power, locking his remains in an inaccessible and inescapable prison.
Afterwards, Arcanos, the God King aided mankind in wiping out all of the Dark One’s creations, and also destroyed everything that had ever been used in his worship. He forbade the use of his name or symbol, with these being passed on only to the most trusted of his worshippers so that they would be able to recognize those foolish or twisted enough to worship the Betrayer.
The Betrayer is always referred to using one of his titles or alluded to using some other nickname, and it is best not to use the same title multiple times in succession.