Abaddon is the keeper of the Gate to the Nine Hells on Earth, as gate he opened himself. He maintained its existence for Zariel, Archduke of Avernus, the First Layer of Hell. until the time when Jericho convinced him to come work for him. Abaddon closed the gate, much to the anger of Zariel. Abaddon helped Jericho curate his Collection by imprisoning all the creatures found within. He eventually was betrayed by Jericho, who feared his power, and became a part of the Collection himself.