User blog comment:B214/Talk About What You Want! 2/@comment-172.56.35.191-20140621054036/@comment-9339850-20140621054526

first things first.. Only Rias is going to be the head of the Gremory Clan, Issei will just be her husband, no actual authority will be given to him other than being served on by the Gremory Clan servants. Second, i dont see why they'd be forced to live in the Underworld; sure it'd be convenient for when they have business on that side, but they can either use magic circles or other forms of transportation to get to the Underworld.