User blog comment:B214/Talk About What You Want! 2/@comment-74.77.52.225-20140801025045/@comment-24502975-20140804233922

You know, if DxD continues to get more and more popular, Ishibumi might end up doing a story after Ise graduates from high school. A short timeskip after Shiva arc and then we enter Ise's life as a High-class Devil.

Or, the more likely option, considering how fast-paced Ise's life is, I wouldn't be surprised if he becomes a High-class Devil by the end of this arc and develops his peerage during the Shiva arc. Hyoudou Residence actually belongs to Rias, so there's no issue with living with his parents (he doesn't seem to mind anyway). Ise's stated that himself several times after the renovations of volume 5.

The way I see it is this:

-During the story, Ise becomes a High-class Devil and forms his peerage

-We don't know how the RG Champion being a traitor is going to change the Rating Game hierarchy, so I'll withhold comment on the "participate in Rating Games as Rias' Pawn" part. But there's still the possibility of the Gremory group being crowned the new Rating Game Champions if they're the ones to defeat Belial and/or his group (not only would the Devils of the Underworld push for it, but if they're that strong already there's not much purpose in having them rise through the ranks normally).

Becoming the Ultimate Pawn and entering the Rating Game himself can be saved for a later time in his life, as well as gaining his own territory and managing it.

Also, providing High-class Devils with a peerage and Ultimate-class with territory of their own is not "plot convenience". High-class Devils already have their own territory, why would they need more instead of the ability to have a peerage (especially when the Evil Pieces were created to increase the Devils' numbers, and therefore shouldn't be so out-of-reach of most of the Devil population).