The True Assassin is a villain from Fate/stay night. He is an exceptionally dangerous Servant with a limited appearance in both said title and Fate/hollow ataraxia but has an expanded role in Fate/Zero. The designation of "True" is meant to distinguish this Assassin from the one that Caster summoned which not only broke the rules of the fifth Holy Grail War but also saw to it that said Assassin usurped this one's place in the war. All True Assassins share a collective identity and have appeared in every Holy Grail War throughout history. They are all infamous for wearing an ebony and tattered costume, as well as concealing their identity behind an ashen skull mask.