User blog comment:B214/Volume 22 spoilers/@comment-9595671-20160808174405/@comment-24583889-20160808192220

This is a good theory and loved the arguement the twp of you had, but you should add this as trivia for both Rias's and Ise's peerage (well after you form a page for his peerage that is) regarding that the girls that that join Rias peerage after Issei would ended up being the latter's personal servant