User blog comment:Jopjopjop/Volume 18 Spoilers/@comment-116.75.184.241-20150118113637/@comment-24468758-20150118191845

It's always the higher-ups of the devils who want him to become a high-class devil before officially becoming a couple in the underworld (even though there are more than enough rumours).

Regarding his position in the supernatural world he is only just the sole existence to hold the powers of the four strongest dragons.

Now quiting with the nitpicking I do understand Zekram as Sirzechs also wants him to be further promoted and he would hold considerably more influence in situation such as the vampire visit in Vol.14, which would become benefitial for the Gremory clan.