The newly appointed Paladin. He was ordered by the Grigori to to interrogate Mephisto and captured Rin as evidence. According to Shura he's a saint on the outside and a devil inside. Uses the demon sword Caliburn.

Not much is known about Arthur so far, except that he is extremely loyal to the True Cross Order. He follows the orders of his superiors without questioning them at all, even attempting to kill people when they interfere with his work. He believes that anything related to Satan must be destroyed, as it could only cause harm to let them live. Arthur also seems to be slightly sadistic, as he stabbed Rin completely through the leg to immobilize him during Rin's trial, while remarking that the wound would heal soon enough. According to Shura, he is a saint on the outside and a devil on the inside, hinting that he may have a malicious personality.