User blog comment:B214/Volume 23 discussion blog/@comment-185.112.105.215-20170419115644/@comment-23853100-20170421020802

Millicas can just form a harem. It's not that hard if he has Sirzechs' good looks. Sirzechs didn't have a harem due to his job. Millicas isn't taking over Sirzechs' job, so there's nothing to prevent Millicas from forming a harem. In fact, Grayfia might be the one that forces Millicas to marry at least one Pure-blooded Devil to ensure the Gremory doesn't go "extinct".

Also Pawn, Nobility is a system, that can be changed. A clan's survival status can't. Don't forget there are also Low-class Pure-blooded Devils, those are known as commoners to the nobles.

"“That is just a school where only high-class devils and devils of privileged rank are accepted. The school that I want to build is one where low-class devils and reincarnated devils can also attend without any distinction.”"

- Volume 5

"“…Even if the current Underworld has changed much from the past, discrimination between the high-class devils, low-class devils, and reincarnated devils still exists. There are also still a lot of people who believe that to be natural as well.”"

- Volume 5

"“I would want all of you who will become the centre of the young generation. The real Devils refer to kins of High-class Devils that has been foretold since ancient times. Others besides that are “servants” and not real Devils. The “commoners” and “reincarnated ones”. Being evil or not will change by the perspectives of humans and other forces. I don’t see the need to become evil. To keep the society of nobles continuing for eternity is what a “Devil” should do.”"

- Volume 18