User blog comment:DeathGodPrayer/Talk About What You Want!/@comment-80.181.161.110-20130914173106/@comment-80.117.65.20-20130927235748

I also thinks that thiamat could be a dragon like ophis that have an human body (she is a dragon that live perfectly in human world and live as she want), she is the strongest of the king dragons and hate Ddraig. It could be PERFECT to be the Issei's Queen!

I think that she hate Ddraig cause she liked him but he thought only to fight against Albion.XD

If she is an humanoid dragon will be a member of issei peerage, and considering her force she will must be the queen.

I think that issei peerage will be with these members (they aren't all, obviously):

Kiyome: Beast tamer

Le Fay: Magician

Kuroka: Nekomata

Ravel: Pure-blooded Devil

Valerie: Vampire

Irina: Angel (there will be a way to make here a servant hybrid angel/demon, i'm sure)

and i think that even Jeanne could change her mind and become a nice Knight for Issei, she would be the Hero of the group. I think this cause her sacred gear, because her life span is decreased so much after the second chaos break and because she's been captured, not killed or backed to khaos brigade, so she could save her life becoming a demon and be free as Issei's knight. But this is just a my theory, i'm not sure of this.