In the endless and empty world of Hueco Mundo, a nameless Shinigami corpse lying on the sand. No body know how did he get there, when did he die or who he is. He just lie there lifelessly... But something start to rise inside of that nameless Shinigami body... A Hollow... No, a nameless Arrancar just got born from that nameless Shinigami... And that is how... That Arrancar story start.

When Rias took a man's choice away from him and made him a devil. She didn't take into account the beast that she unleashed upon the underworld.