Amata Kihara

He was first introduced in volume 12 of the novels, he is a sadistic scientist who was the Commander of the Hound Dog, a Black Ops force that serves directly under Aleister (Since Academy City does not have an "official" Black Ops force, but many of the 12 Directors have their own personal Black Ops force, while others prefer to set up groups like ITEM or SCHOOL). He is the man who discovered Accelerator and his former guardian and teacher, whom the former constantly abused and trained the latter by subjecting him to various experiments that were designed to kill him which left the other participants dead and extreme training to teach Accelerator how to use his powers properly. He reunites with his former student when the Hound Dog are ordered to kidnap Last Order from Accelerator. Amata proves to be a difficult opponent for Accelerator as the former manages to physically hit him repeatedly without being affected by the latter's powers as Amata understands how his powers work and even used it against him.