User blog comment:Mnzombie/Issei's Peerage/@comment-5185939-20120617235352

I wouldn't be surprised if Issei has the girls stay with Rias so that he can have a larger harem by adding girls to his own Peerage.

Plus, if needed, he and Rias can trade between themselves to fit a situation. Only exception would probably be Pawns as that would mean Issei would be both King and his own Pawns.

As for who will join his Peerage...

Queen: Tiamat (if not Familiar) Yasaka

Rook:

Knight: 1. Irina (If she Falls) 2

Bishop: 1. Ravel Phenex 2. Kiyome Abe (Le Fay Pendragon third choice)

Pawns:

All I've got for canon characters at present.