|Also known as:||Old Man of the Mountain|
|Appears in:||Fate/strange fake|
|Character type:||Servant (Master: Faldeus)|
Assassin remains always hidden, though he is shown wearing the skull mask that every Hassan wears.
Upon meeting his Master, True Assassin questions Faldeus' convictions and whether or not they are worth taking the lives of others for, declaring that is what it is to form a contract with him. He agrees to be his Master's Shadow so long as he does not abandon his convictions. Assassin speaks in an old manner, for example using "thee" instead of "you".
When Faldeus first summons True Assassin, the Servant doesn't appear, causing Faldeus to believe that the summoning has failed. However, it's revealed that True Assassin was able to hide himself, even from his Master, communicating to Faleus by writings. True Assassin speaks with Faldeus, though he remains hidden from him, asking if Faldeus has strong faith in something and if he is ready to kill. As Faldeus answers positively to both, Assassin agrees to make a contract with him.
As more and more people are infected by an unknown disease in the city of Snowfield, where the Holy Grail War is being held, Assasin is shown being aware of the one causing this epidemic, calling it a curse-plagued wind, and informing Faldeus that it shouldn't be able to get inside their base of operations. When Faldeus becomes more concerned about Bazdilot Cordelion, the Master of True Archer and a member of the Cordelion crime family, he decides to send Assassin to kill the head of the family, Galvarosso Cordelion, who is currently residing at the other side of the country. Before departing on his mission, Assassin asks one last time if Faldeus has the fate necessary to kill, warning that if it is proven later that he does not "the curse will rebound and devour him".
Faldeus later hears from the news that many associates of Galvarosso Cordelion have mysteriously died of what seems natural causes. It is unknown if Assassin is related to these deaths, and Faldeus is yet unable to confirm if Galvarosso himself has been killed.
Assassin's Presence Concealment is EX, and drops to A+ when he starts to attack. His other parameters and Noble Phantasms are obscured. Assassin is very skilled in acting in secrecy, being able to write down words on paper and slip them into his hand, even going so far as to manipulate his Master at first into writing them, without even Faldeus himself noticing. He possibly can manipulate darkness as well, shutting off lights in a hall when he encounters Faldeus for the first time to establish their contract, or in his office during verbal encounters.
- ↑ 1.0 1.1 1.2 1.3
 Fate/strange fake - Volume 2 - Servant status: True Assassin
Class: True Assassin
Master: Faldeus Dioland
True name: Hassan-i-Sabbah
Strength: Even Faldeus cannot confirm
Endurance: Even Faldeus cannot confirm
Agility: Even Faldeus cannot confirm
Magic: Even Faldeus cannot confirm
Luck: Even Faldeus cannot confirm
Noble Phantasm: Even Faldeus cannot confirm
■ Presence Concealment: EX
Becomes one with the World itself. The moment one shifts to attack, it becomes A+.
■ Shadow Lantern: A
Skill that allows one to become one with the shadows. Because he can gain surrounding magical energy from the darkness, as long as he does not materialize he almost doesn't need the Master's magical energy supply. As long as a command spell is not used, it is possible to conceal one's status from the Master.
■ (Obscured in volume 2)
Maximum Targets: ???
- ↑ Fate/strange fake Volume 2, Chapter 5: "A Shadow in the Park"
- ↑ 3.0 3.1 Fate/strange fake Volume 3, Chapter 7: "The Canon of the Demigods"
- ↑ Fate/strange fake Volume 3, Chapter 9: "A Horse Not Yet Pale; Mud Yet Firm"
- ↑ Fate/strange fake Volume 4, Bridge Chapter: "One Day, Above the Sky"