User blog comment:Ixarising/Rating Games pairing you want to happen in the story./@comment-71.108.70.155-20131127185241/@comment-1359322-20131128084402

Just one problem with your theory, if Issei does that he'll be both the King and Pawn of his very own team. It'll make Issei look weird. Also Issei already said he'll be Rias' Pawn for the rest of his life.