User blog comment:B214/High School DxD DX.4 discussion/@comment-2601:8C:601:5692:3D30:770C:CE5:1085-20170725134222/@comment-31137559-20170728150603

Well when was it stated that it was mandatory for a high-class devil to receive evil pieces and become a king? If you offered everyone in a room to become the leader of their own group, do you think everyone would take the offer? Do you think that everyone wants to be a leader? Some pureblood high-class devils don't want to become kings. Some might want to fight on the frontlines and receive the benefit an evil piece offers them and serve under another high-class devil. Offer a thousand people the chance to become leaders of their own groups, and you're going to have those that don't want to. Basically all pureblood devils of the existing 72 Pillars are high-class devils. They are all nobles because of them being from noble families. If the noble pyramid worked as you say, then Rias, Sona, Sairaorg, and Seekvaira should be Ultimate-class devils. All of them have noble titles like the Duke of Gremory, Archduke of Agares, Great King of Bael, etc. They are all high-class devils regardless of their title. I'm not even sure how that noble pyramid works with it listing the titles in different classes like low-class, mid-class, high-class, and Ultimate-class. Because all of those from the existing noble families of the 72 Pillars are all high-class devils.

And Sairaorg and Magdaran are high-class devils from the House of Bael. The House of Bael stands at the top of the 72 Pillars being the highest-ranked noble household with the rank of Great King. So it would be typical for those from the House of Bael to have high-class devils from other noble families to be their servants. For example, Sairaorg has his queen, Kuisha Abbadon, his knight, Beruka Furcas, and his rook, Gandoma Balam, who are all high-class devils from noble families with Kuisha being from the Extra Demons and Beruka and Gandome being from the 72 Pillars. And Magdaran has his queen, Sectaas Barbatos and his bishop, Veves Furfur. Both from the 72 Pillars.

So there are high-class devils who simply don't want a peerage and would rather be a servant. They still keep their rank. For example, Kiba wants to stay as Rias' knight forever and Saji wants to stay as Sona's pawn forever. Neither of them have expressed the desire to become kings and don't want to. But yet they still want to be promoted. And the servants of the Maou/Satans are able to participate in Rating Games. But the servants of the current Satans have no interest in doing that and are dedicated to being the servants of those Satans. That kind of implies that are all(or most of them) at least high-class devil, if not Ultimate-class devils but decided not to have a peerage. That's something that really annoyed me about most fanfics is that all high-class devils want a peerage although we have Ravel, Grayfia, Kuisha, Beruka Furcas, Gandoma Balam, Sectaas Barbatos, and Veves Furfur who all decided to become another high-class devil's servant rather than being the king of their own peerage. It was never stated that every high-class devil wants evil pieces and to become a king and form their own peerage. Neither was it stated it was mandatory to do so.