User blog comment:15sok/How Would Issei Human Friends Feel About His Secret/@comment-6482575-20131217082255/@comment-16281343-20131218015321

That's why thet will be reincarnated using Ravel's Evil Pieces, not Issei's

Ravel is already qualified to acquire her Evil Pieces but she still hasn't created or even thought of creating her own peerage. So instead of those unused Evil Pieces who are just hanging around, she can use those for Issei if he wishes for those two to be reincarnated even though they have no redeeming qualities whatsoever.

~ And with that in mind, wouldn't it be like a cheat in the Rating Games if a King also has a King in her/her peerage?

It will be like the principal King will have, at most, 28 servants that he/she could use. He/She could just trade his/her servants temporarily to adapt to scheduled battles?