User blog comment:DeathGodPrayer/Talk About What You Want!/@comment-82.40.154.8-20140102000134/@comment-16281343-20140102001802

The "knight" that Sona originally wants to recruit is a plot hole that may or may not be filled.

I don't think Rugal will play a bigger role since his is already filled. A new member of Sona's peerage that is a natural enemy of the vampires which are antagonists in Volume 16. And also Rugal is not much of a character that Ishibumi will devote a volume for him, like what he did with Kiba. Maybe his background will help in some point, but not that big.

In Bennia's case, I don't see her being Issei's knight. I even vote for the one Sona wants to be his knight, not her. Bennia's background may play an important role in the future since his father is somewhat an important figure or a powerful one in the Greek Faction. Hey, if Volume 17 will center the Norse Faction (that's just my guess since it will be Ross'), maybe we will see where the Greek Faction will be used as a settting.