Hassan of the Cursed Arm (呪腕のハサン, Noroi-ude no Hasan?), Class Name Assassin (アサシン, Asashin?, Asashin), is the Assassin-class Servant of Zouken Matou in the Heaven’s Feel route of Fate/stay night. Designated as True Assassin (真アサシン, Shin Asashin?) in reference materials, he is the proper Servant meant to be summoned under the Assassin-class rather than Sasaki Kojirou in the Fifth Holy Grail War. He is also a Masterless Servant in Fate/Labyrinth and one of the Servants summoned by Ritsuka Fujimaru in Fate/Grand Order.