A noble, a mathematics professor, and the first ever "crime consultant," William is a genius who attempts to overthrow evil nobles and destroy the corrupt class system.
He and his brother Louis were orphans who were adopted by the Moriarty family after Albert noticed his capabilities and began believing in his ideals of overthrowing the evil nobility. At Albert's request he concocts a plan to kill the remaining members of the family and make it look like an accident. After burning the entire manor down, he adopts the name of the son he killed, William James Moriarty, and begins living as a noble.