User blog comment:Mnzombie/Issei's Peerage/@comment-71.108.70.155-20131114195856/@comment-95.232.176.117-20131117140746

A Queen must be extremely powerful, is the strongest of the evil pieces. Issei Queen could be Tiamat (a dragon king, if could shape in a human girl, like Ophis and Crom Cruach do.) Or could be Valerie, that is a longinus wielder with incredible powers.

And Issei could have all girls in his peerage if they are strong. Female not mean "weak" in this light novel, there are so much girls that are strong.