Graham was a misfit who, like Anos Voldigoad, he was powerful enough to defy the orders of the gods. He claims to be the leader of the Phantom Knights; Celis Voldigoad, father of Anos before reincarnation.

Graham is ruthless, manipulative, and twisted. He is usually seen with a smile that is both carefree and empty, and you can't tell what is going through his head because of this.

Graham is shown to be very skilled at wielding his scythe, Befenguzdogma, as he is fully capable of integrating its unpredictable attacks into his battle style. He is shown to be skilled enough to put up a fight against Anos, who was wielding Venuzdonoa.

(Source: Maou Gakuin Wiki)