Senji Muramasa is a character in the mobile game Fate/Grand Order. He is a legendary blacksmith from Japanese folklore, known for crafting swords with unparalleled sharpness. In the game, Muramasa is presented as a Saber-class Servant, embodying the soul of the blacksmith within a humanoid vessel. Despite his gruff exterior, Muramasa is a deeply principled individual, dedicated to his craft and the preservation of his ideals. His role in Fate/Grand Order is pivotal, offering the protagonist guidance and assistance during key battles, and his presence often brings a sense of wisdom and strength to the unfolding narrative.