King Hassan, also known as Hassan of the Fathomless Rift, is the True Assassin Servant in Fate/strange Fake. He earned the title of Old Man of the Mountain by becoming the shadow of death rather than leading the Hashshashin. Known as the Wandering King, he exists at the border between history and myth, representing the last king with one foot in an age when faeries and runes were still openly present. He previously fought alongside Saladin and other Hassan leaders against a Dead Apostle during the Third Crusade. As a Servant, he embodies an anti-hero nature with human attributes, feared throughout history for his mysterious and unpredictable nature.