Assassin (Fate/Grand Order - King Hassan)

Assassin (アサシン) is an Assassin-class Servant appearing in the Grand Orders of Fate/Grand Order. He is a Grand Assassin (グランドアサシン). He threw away his rank of Grand during the battle with Tiamat but it is unknown if it was permanent.

Identity
Assassin's True Name is Hassan-i-Sabbah, founder of Hashashin sect, called the original Old Man of the Mountain (山の翁). He is given the nickname of "King Hassan" ("キングハサン") by the Protagonist.

Personality
King Hassan comes off as quite the stern and straight-forward individual. He possesses extremely low tolerance for impoliteness, as he almost immediately annihilated the protagonist's group upon their uninvited visit to his temple.

However, he is far from being heartless, simply a man with unshakable faith and strict code of conduct. He was willing to hear his visitor's plea for aid and accept it, but only on the condition that one of the Hassans be willing to die for it.

In his view, for a Hassan to plea for aid, even from their own kind is a grave dishonor to their name and faith, as they are those who must rely on their own individual strengths to preserve through trials and slay their targets. Any Hassan who grows weak and/or becomes reliant on the strengths of others must be dealt with by his blade.

Abilities
Unlike all of his successors, King Hassan has been describes as one who kills his targets not physically, but by severing their 'fates' through a power similar to the Mystic Eyes of Death Perception.

Interestingly, in a manner similar to Shiki, King Hassan wields a sword that may act as a medium for his abilities. In term of actual swordplay, he is more than a match for the knights of Camelot. He has shown feats like being able to deal with Gawain and block Excalibur Galatine with his cape, he is able to create sandstorms and kill even abstract concepts like the communications with Chaldea or Ereshkigals alliance with the other goddesses in Babylonia. He is able to insert the "concept of death" to unkillable beings like he did with Tiamat in the 7 singularity.

His personal skills are Battle Continuation EX, Protection of the Faith A+++, and Evening Bell EX.

Azrael: The Angel that Announces Death
King Hassan holds the Rank C Anti-Unit Noble Phantasm. Though the broadsword that he bears is perfectly commonplace in appearance, it has across the lifespan of its wielder been stained in the colors of his faith. As a sword borne by a man who walks unto the boundaries of the Valley of the Shadows Death (幽谷の境界), its edge can potentially impose the termination of life with slightest cut. Though the occurrence of this imposition is uncertain and low in probability, so long as it comes into effect, any opponent can be instantaneously felled.

Those that walk within the Valley are as one with Death, and are as such resistant to its instantaneous imposition, as well as the effects of mental interference.

King Hassan is the only Hassan with a Noble Phantasm not dubbed with the name Zabaniya.

Presence Concealment
Presence Concealment (気配遮断), Rank A -- the capacity to eliminate one's presence. Effectively, the remains of a skill acquired long ago. Being that the skillholder in question is a swordsman who bears upon his person a curse of immense strength, even if an attempt at the concealment of presence is essentially flawless, any target to which the skillholder intends mortal harm would be capable of discerning the existence of a threat.

Evening Bell
The Evening Bell (晩鐘) signals the announcement of funereal proceedings; the visitation of Death. This unique skill manifests in consequence of coming to be one in existence with the rites of passing. The swordsman of the Evening Bell is without agency in his choice of opponents; he is the manifestation of momento mori -- the divine salvation that befalls all of those who have lost sight of their mortality (死ぬべき時を見失った). A termination is brought upon the fates of those who would oppose the heavens; the granting of a final opportunity for those who stray, that they might come to rest while they remain as men.