User blog comment:B214/Question and Answers 6/@comment-82.2.190.195-20170201191241/@comment-29963364-20170202082716

I have a thought I'd like to add in regards to why the Devil higher-ups suspected & held Grayfia prisoner:

While some (if not most) did suspect her of hiding the fact that Euclid was still alive, and that she may be a traitor, I think that others had a different motive for placing blame on her.

Some of the more "power hungry" Devils probably didn't care whether or not Grayfia hid the truth, and only wanted to take advantage of the situation to advance their political influence.

If the wife of a Satan is under suspicion and/or accused of being a traitor, then that Satan's movements & activities would be severly limited, and the "power hungry" Devils could use the wife as a hostage/bargaining chip to get the Satan to do whatever they wanted.