Movie
Description
The Old Man of the Mountain, also known as First Hassan or King Hassan, is an Assassin-class Servant who appears in the Camelot story arc of Fate/Grand Order, including the two-part film adaptation Divine Realm of the Round Table: Camelot. He is regarded as the first Hassan-i-Sabbah, the figure from whom the title Old Man of the Mountain originally derives. In the lore of the assassination cult, he is a nearly mythical presence: neither the other eighteen Hassans nor the cult's followers knew his true identity, and no evidence of his existence could be found anywhere. He is said to appear to take the head of a generation's Hassan-i-Sabbah whenever that leader strays from the cult's proper path, making him an assassin who kills other assassins. To give that contradictory duty a just cause, he chose to fight openly with a large sword instead of concealed assassination tools, and it is said that anyone who catches sight of his skull mask has already met their end. He reportedly lingered in the darkness of the cult until the day of its ruin.

In the Camelot singularity, he serves as a key ally to the Chaldean party. He dwells in the mountains, where he keeps a shrine, and his stern and straightforward nature means he has little tolerance for disrespect; those who approach him without invitation may be met with lethal force. Despite his terrifying appearance and fierce manner of fighting, he is not wantonly cruel. He is silent and speaks rarely, and he has a noble disposition that strictly follows divine teachings. He distinguishes between the suspension of life activities and the true end of life, understanding the end of life as a form of salvation granted by God's will. Accordingly, he does not choose his victims of his own free will; rather, he brings release to those who have lost sight of their moment of death, acting in place of Heaven. In battle he shows no mercy and inspires the same dread as death itself, yet his rare words and intentions are always conveyed clearly.

His motivations in the Camelot story are rooted in judgment, faith, and gratitude. As one who condemns evil in the name of the Lord, he shows no mercy to the wicked and would cut down even a believer who carries evil within them. During the conflict with the Lion King, he chooses to cast aside the title of Grand Assassin in order to return a favor to the Master of Chaldea, who had reached the hearts of the mountain people and broken through the influence of the Lion King. By abandoning his grand title, he becomes the sword of the summoner and lends his full strength to the Chaldean expedition, making him a decisive participant in the struggle against the Lion King's forces.

His key relationships include the Master of Chaldea, toward whom he displays no conventional loyalty but whose trust he answers with the entirety of his soul; the other Hassans, toward whom he acts as an unrelenting and strict senior who judges their failings; and the Lion King, whose rule he opposes. His development in the Camelot arc is defined by this deliberate surrender of his highest standing, transforming him from a detached arbiter of death into a committed ally fighting for the Chaldean cause.

His notable abilities reflect both his assassin heritage and his unique position at the boundary between life and death. His Noble Phantasm, Azrael: The Angel Who Foretells Death, is an act of decapitation carried out with an ordinary great sword steeped in a lifetime of faith; those who perish by it experience fear without pain, dread without suffering, and repentance without regrets. He possesses high-ranking Presence Concealment, though the curse he carries means his intended target perceives the premonition of their own death as he approaches. He also has Magic Resistance, Independent Action, and the skill At the Boundary, which grants immunity to instant death and charm while adding a chance of instant death to every attack he makes. His Battle Continuation is exceptionally high, allowing him to keep fighting even after wounds that should be fatal. His Protection of the Faith reflects the absolute conviction that reshaped his body and mind, and his skill Uncrowned Martial Arts conceals the true extent of his abilities, meaning his real parameters are higher than those displayed. He is also accompanied by an evening bell that announces death, a manifestation of his unity with funeral rites and the summons of the end.