User blog comment:B214/Question and Answers 6/@comment-187.180.176.223-20190619153726/@comment-28884330-20190710024048

The closest I found to what you say is that he considers the Pillars as "Real Devils", unlike reincarnated devils and such. There's nothing even close to what you say of the Gremory being kicked out of the pillars if Rias marries Issei. He straight up says he won't oppose it, actually. I also don't really see how him considering the Great King as the highest authority has much to do with this. That's true, but it's a side note. Devils don't value the Bael over the Maou because of blood purity (all of the current Maou are pure-blooded), but because the Bael are the ones who handled the Underworld and helped its society transition after the original Maou died.

Accounting for how the narration has gone out of its way to describe Zekram positively, I find your speculation to be a very large jump. Zekram is not Lelouch Lamperouge, lol.