User blog comment:B214/Volume 21 info & spoilers/@comment-95.90.224.210-20160602194640/@comment-73.160.58.215-20160604221422

Indeed,  she  (Roygun) is a user of the King Piece, but that doesn't mean that she isn't stronger than the other Devils without it. With the exceptions of Sizechs, Ajuka, Serafall, Falbium, Grayfia, and Diehauser, she very well may be naturally amongst the most powerful Devils but was unable to compete with the Top Rankers because they used the King Piece, thus she chose to accept one as well in order to fully enjoy the Rating Game dominated by its users. Besides, Sizechs and company were using the current situation to set up a new Satan (Maou) system -- one that very well might involve other factors besides pure strength for determining it's members that she possesses. Most likely Diehauser and Roygun are indeed two of the new Satans and the third new name most likely comes from the House of Mammon.