User blog comment:B214/Volume 22 spoilers/@comment-30319856-20161025113305/@comment-30048084-20161031151319

I just thought of a random possibility maybe Bina is Roygun Belphegor.

My reasoning is that what if the punishment for using the king piece is to

a) have said piece removed from said devil and lose one's rights to be a king indefinitely, blacklisted from the rating game, further punishment will be decided upon at a later stage.

However Roygun asked Ise if he she can be his queen after losing everything because of her joy for the game, which Ise found to be interesting, Roygun hopes that because of Ise's status in the underworld she might be granted some degree of mercy so that she can still do the thing she loves.

Why her power is that of a slightly above average high-class devil is that she no longer possess the king piece, it is also the reason why she doesn't make mistakes. Why she isn't telling Ise what he should using her experience is because she wants him to learn how to be a king on his own.