As William, he has short, neatly-combed, brown hair, green eyes, and wears rectangle-shaped glasses that have four decorative lines on each side of the frames. He usually dresses in a nice black suit, tie, black gloves, and dress shoes. He is 6'0 tall.
William is a human who can transform himself into a cat, as well as his friend, Grell. They later find more humans who can do that, and that they formed a clan.
So, the two friends joined, becoming Silentstrike and Redflame, respectively.
William/Silentstrike is emotionless and generally calm. He does seem to show more emotion around his best friends, Grell, and his brother, Ronald, but otherwise he does not appear to like anyone very much.
He's a workaholic, and is always very stressed, something that Grell notices and tries to cure.
He has trust issues with strangers, steming from his mother's boyfriend's abuse of him as a child.
- He is based of the Kuroshitsuji character William.