Lucifer of Mammon

Instead of Riser Phenex, Rias is engaged to someone else. Damian Mammon-Lucifer, heir to the Houses of Mammon and Lucifer. He is sent to Kuoh Academy with Rias, and a whole mess of problems follows with the likes of Fallen Angels, crazy Exorcists, and a massive terrorist group called the Khaos Brigade. Rated M for language, nudity and sex. It's DxD after all.