James Moriarty, known as the "Napoleon of Crime," is a powerful and cunning antagonist in the Fate/Grand Order series. As an Archer-class Servant, he possesses a brilliant mind and an unparalleled aptitude for strategy and manipulation. Moriarty's role in the series is often as a mastermind, orchestrating complex schemes to achieve his goals. His character is inspired by the infamous villain from the Sherlock Holmes stories, and he brings a combination of intellect and malevolence that challenges the protagonists at every turn.