According to [[Death]], before there was life, the Earth, or even God and the [[archangels]], there was [[the Darkness]]. God and His archangels defeated the Darkness and locked it away rather than destroy her to maintain [[the Cosmic Balance]]. God created the Mark to act as the lock and key to the Darkness' cage and if it was to destroyed, the Darkness would be released. God gave the Mark to his most trusted lieutenant, [[Lucifer]], but the Mark corrupted Lucifer and made him jealous of humanity which led to his imprisonment in [[Lucifer's Cage|the Cage]]. Prior to being locked away, Lucifer passed the Mark to [[Cain]] as part of his deal to save Abel from Lucifer's influence.
After Cain was given the Mark, he began to realize what kind of toll bearing the Mark would take after he killed Abel, and rather than be controlled by his murderous compulsion, he attempted to kill himself with the First Blade. However the Mark would not let his [[soul]] depart to the afterlife. After Cain's soul was twisted and corrupted by the Mark's dark, primal energies, he was reborn as a [[Knight of Hell]], the very first of his kind. Cain would go on to train and lead damned souls handpicked by Lucifer to be the Knights of Hell, and would
wreaked havoc on Earth for centuries as the harbingers of chaos and darkness.<ref name="nine11">[[9.11 First Born]]</ref> .
After centuries of murder and mayhem, Cain fell in love with [[Colette Mullen]]. The Knights took retribution and took Colette, forcing Cain to use the First Blade and its energy drawn from the Mark to slaughter all the Knights except for one; [[Abaddon]]. Despite Colette's death by Abaddon's hands, Cain managed to cease killing, keeping his final promise to his wife. After burying his wife, Cain disposed of the First Blade in the Mariana Trench.