User blog comment:IamJakuhoRaikoben/Chapter 393: Silver Memories, Review./@comment-77.195.192.49-20140717105931

And if Silver killing other demons was part of Tartarus plan to gain curses and revive END ? Keith chose him because of his anger towards demons, made Tartaros believed he was Deliora and let him kill other demons and at the same time gain an asset in the cause of one of the 9 gates became too "human". So basically Keith and Mard are the only one who are important in Tartaros, all the other demons are just slaves or war machines