Zabaniya (ザバーニーヤ, Zabānīya?) is the name of the Noble Phantasms of all the nineteen people who have taken the title of Hassan-i-Sabbah. Each one of the nineteen had to earn their title by proving their piety through obtaining a divine miracle bearing the name of Shayṭān that met the criteria of that which could swiftly and reliably bring death to its target. All of them, with the exception of The Hundred-Faced Hassan who had a qualifying in-born ability, modified their bodies to achieve their own miracles, earning them their titles. They are currently keeping their abilities as concealed "ultimate techniques", all with the name Zabaniya, for the purpose of taking down the other eighteen Hassans so that they can vie for the position of Leader of the Assassins.
The techniques have not been passed down in history like regular Noble Phantasms, but instead because the Assassins themselves are a famous anecdote. Due to being the abilities that have established them as Assassins by virtue of being placed as the Old Man of the Mountain, the superhuman abilities they had in life are sublimated as their Noble Phantasms. The No Name Assassin, a failed candidate for the position, is noted to have copied eighteen of the techniques, accumulated into Phantasmal Pedigree. Each which would take a lifetime to master for a regular person, but she extensively modified her body in only a matter of years. She only lacks Delusional Illusion, the Zabaniya of her compatriot also vying for the title in the same generation she lived in. Although possessing the talent, strength, and fortitude to master the previous eighteen miracles in a matter of years, she was unable to innovate her own original miracle, so she was rejected as the next grandmaster for that reason and her people feared her ability in so quickly mastering the other miracles.
Zabaniya: Cyber Phantasy (空想電脳, Kūsō Den'nō?) is the ability of the Assassin summoned during the Third Holy Grail War of Fuyuki. Upon contact between an enemy's head and one of Assassin's hands, it turns the target's brain into gunpowder, causing it to explode and destroy the upper half of their body. He utilizes poisonous needles and his small stature to catch his opponents off-guard to touch his left hand on their foreheads. No Name Assassin also possesses the ability through Phantasmal Pedigree.
Dead Heartbeat MelodyEdit
Zabaniya: Dead Heartbeat Melody (亡奏心音, Nasō Shin'on?) is an ability possessed by the Assassin Class Card of the Fifth Ainsworth Holy Grail War. It is Installed and utilized by Shinji Matou. It allows, through a yet unknown method, for the user to pierce a peculiarly shaped hole in their target by holding their hand up to their chest.
English | Japanese
"Overflow with anguish――"
Zabaniya: Delusional Heartbeat (妄想心音, Mōsō Shin'on?) is the ability used by the Assassin summoned in the Fifth Holy Grail War of Fuyuki. No Name Assassin also possesses the ability through Phantasmal Pedigree. It is the arm of the evil spirit Shayṭān, the cursing hand of the Middle East magecraft specialized in curses that curses humans to death. It takes the place of his right arm, which he normally keeps wrapped in cloth, making it seem like a useless appendage without a hand. After removing the cloth, he reveals that the "clubbed stump" of the arm is actually the elbow, and the arm itself is folded back and sewn to his shoulder. Once unleashed, it rips away from his flesh and flaps like a "one-winged spear." The arm's ability is one of the purest magics and simplest curses but of an extremely high level. It creates a mirror image of the heart of the assassination target with an ether clump, a dual existence that resonates with the original one. By crushing the fake heart, he can crush the real one with this curse without laying a finger on it. It is also possible to switch the two existences by touching the target's chest, allowing Assassin to devour the heart and gain the opponent's intelligence. It may not mean instant death to some opponents, allowing for the chance of a final counterattack before death.
The ability completely neutralizes all physical barriers and armors by only interacting with the fake heart, meaning that all physical defense and distance is rendered meaningless. It would simply bypass an armor with a defensive rating of one thousand and directly deal damage. The way to resist the curse does not fall under Endurance, but rather, the target must simply stay out of Assassin’s range, have a high enough Mana statistic to prevent the overlaying existence from even being created, or have a high enough Luck to avoid it without any problem. It can be considered a convoluted and indirect way of killing a target, only fitting for an assassination, that is more akin to a trick used by a magician The ability, bearing the name of the angels of hell, "Zabaniya", is only able to target and punish humans by cursing them to death. It is unable to curse its own kind, rendering it ineffective against evil spirits or those affected by their curses. When used against Kirei Kotomine, whose heart is under the curse of Angra Mainyu, Assassin simply feels no solid response from the ether clump, as if the heart is empty.
Unlike other Hassans, the Cursed Arm Hassan himself possesses no special talent, so he obtains this ability by sacrificing his right arm to a demon god, sealing said demon in his arm in the process.
English | Japanese
"We as a group is an individual, and the individual, a group. The group's innumerable shadows possesses a hundred faces. Now..."
Zabaniya: Delusional Illusion (妄想幻像, Mōsō Genzō?) is the ability used by The Hundred-Faced Hassan, who was the Assassin summoned during the Fourth Holy Grail War of Fuyuki. It is an Anti-Unit Noble Phantasm that targets Assassin himself rather than an opponent. Assassin is a single entity, but he possesses a compartmentalized soul and multiple personalities that allow him to divide his spiritual potential to materialize up to eighty different Servants. Though limited by his physical body during life, his thousand souls are now free of such limitations as a spiritual entity, and as each segment can materialize as an individual, they can all be materialized simultaneously in different shapes.
Each one is its own separate entity, and the only shared characteristics are their skull masks, black cloaks and race. Their body sizes can be giant, slim, short as children, and some can even be women. They each have their own will, personality, strengths, and weaknesses, and although they are against unnecessary sacrifice, losing one without a specific strength does not directly affect the whole of the others more than losing a finger, but that individual along with their characteristics and abilities will vanish and not be restored to Assassin as a whole. There are those who are impatient glory-hounds who ignore orders like fools, and individuals who are terrible at ambushes despite being assassins. It is possible to produce egos that are not aware of themselves, such as the Child Assassin, that are not counted among the eighty divided Servants. All existences of Assassin are equal, none of them created or designated as a superior or subordinate of one another nor is any a "real form" or a "offshoot" of the whole. Despite any drawbacks, if one can comprehend their characteristics and apply their skills in the right situations, Assassin can be a very dangerous Servant.
This ability allows for Kirei Kotomine and Tokiomi Tohsaka to make the other Masters in the war believe that Assassin was decisively killed by sacrificing one of the bodies. They can be split up for reconnaissance, but they have to directly speak to each other to communicate information and decide on orders as they are not connected by telepathy or other similar connections. If the Master has the ability to see through his or her Servant's eyes, he is limited to a single Assassin at any one time. If they are separated on numerous different assignments, it can take up to ten minutes to summon them all together in one spot. Due to the potential of the spirit being that of only one person, the abilities of the Assassins produced by the division is extremely low, reaching the lowest point of the capabilities of Servants. As his statistics are divided among the bodies, it means that they are unable to match any Heroic Spirits in direct combat, nor does it allow him to equal a small army. Though not suitable for combat, their abilities are unparalleled in terms of spying and gathering recon as their Presence Concealment Skill, the inherent Skill of the Assassin class, will not decline in effectiveness. By making maximum use of this, they can transform into an excellent and extraordinary intelligence system. Their high numbers do allow for a final resort strategy to kill an opponent's Master or Servant by sacrificing the greater whole in order to overwhelm the opponent with pure numbers.
During life, the Hundred-Faced Hassan was the only Hassan without the need to modify his body in any way. Though his strength was typical, he had a special ability, taking advantage of his affliction of Multiple Personality Disorder, allowing him to change his body freely with his mind to disguise himself as a man, woman, child, or an elder to act as an assassin without a true identity. He was able to change his personality solely based on the situation, allowing him to confuse opponents, weave webs of defense, and kill them with unexpected and unpredictable methods all while hiding his true identity completely. He had a repertoire of abilities allowing him to act as a master assassin capable of doing anything by switching abilities depending on the requirements of his assignments. He had impressive skills in planning and tactics, knowledge of all languages of other countries, the ability to identify poisons and set traps, and on occasions displayed the capability to utilize strange strength and agility to use illusionary, long forgotten fighting styles. Other skills employed by the Assassins include impersonating Toyotomi Hideyoshi and chick sexing.
In the world of Fate/kaleid liner PRISMA☆ILLYA, the ability is deteriorated down to Rank C+, so the maximum number of bodies that can be created is limited. When using it to Include, the item used to include will become a decoy in the exact image of the user. In the case of Magical Ruby, it can continue to act in the user's place. The user is concealed at the same time, and they will be revealed after the decoy is destroyed.
Delusional Poison BodyEdit
English | Japanese
"Hot... Hot... I will openly melt... and thoroughly burn your body and mind."
Zabaniya: Delusional Poison Body (妄想毒身, Mōsō Dokushin?) is the ability possessed by the Hassan of Serenity, an attempt by the Order to replicate the Indian Visha Kanya (Poison Girl). It is her own body, instantly killing those who touch her. It is said that this Hassan possessed the power to spread this deadly poison on the wind, wiping out entire armies if necessary, but also lacking in the capacity to discern friend from foe, making it equally devastating to her allies. No Name Assassin also possesses the ability through Phantasmal Pedigree.
Zabaniya: Febrile Inspiration (断想体温, Dansō Taion?) is an ability of one of the first eighteen Hassan-i-Sabbah. No Name Assassin also possesses the ability through Phantasmal Pedigree. Unlike the other forms of Zabaniya, this technique is defensive in nature as it transforms the users' skin into a special type of crystal.
Ichor of ReverieEdit
Zabaniya: Ichor of Reverie (夢想髄液, Musō Zuieki?) is an ability of one of the first eighteen Hassan-i-Sabbah. No Name Assassin also possesses the ability through Phantasmal Pedigree. It allows for the use of an extremely high-pitch "song" that disorients the targets' brains and scrambles their Magic Circuits. It can instantly kill nine magi actively preparing spells by forcing them to incinerate themselves. It can also be focused on a single target, forcing even a Servant onto their knees with this disorientation ability.
Zabaniya: Meditative Sensitivity (瞑想神経, Meisō Shinkei?) is an ability of one of the first eighteen Hassan-i-Sabbah. No Name Assassin also possesses the ability through Phantasmal Pedigree. It allows for the honing of senses to extreme levels. Differing from the other Zabaniya techniques able to be faithfully reproduced by No Name Assassin, Meditative Sensitivity is unique in that it cannot be connected to any of the Hassans outside of stories telling of one using the technique, so it is impossible to say if its usage by her is correct or if the technique was even used by one of the previous masters.
Zabaniya: Phantasmal Pedigree (幻想血統, Gensō Kettō?) is the ability possessed by No Name Assassin. It is a combination of all eighteen Zabaniya techniques from before her generation, only missing Delusional Illusion from the same generation as her. Some of the techniques are either stronger or weaker than the originals.
- Delusional Heartbeat - Differing in that she has not replaced one of her own arms, she has a red third arm emerge from her back that performs the ability in the same manner as the original.
- Delusional Poison Body - Compared to the Hassan of Serenity who could poison entire armies, No Name Assassin limited the concentration of poison to affect only her body so as to keep her from harming her allies and innocent people.
- Cyber Phantasy - Upon activation, her shoulders begin to warp while producing a wet, aberrant sound, allowing her to move her left arm at an abnormal angle behind her body. Gently touching her opponent's head causes their head to erupt into flames and splatter like a bomb has been set off.
- Ichor of Reverie - Improved from the original, the sound can be focused onto a single target to force a normal Servant to their knees or to control the brain of a normal human.
- Raving Shadow Flash: Though similar to the original technique, the original user had more skill using the technique, being able to control each strand of hair like a spider's string.
- Febrile Inspiration
- Meditative Sensitivity - Due to the fact that she could not confirm its usage, she recreated the technique based on stories only, so she does not know if the technique is correct or even if one of the past leaders really used it in life.
Raving Shadow FlashEdit
Zabaniya: Raving Shadow Flash (狂想閃影, Kyōsō Sen'ei?) is an ability of one of the first eighteen Hassan-i-Sabbah. No Name Assassin also possesses the ability through Phantasmal Pedigree. It allows for the manipulation of one's hair to be used as a cutting tool. The Hassan who created the technique displayed enough prowess to make their strands as thin as spider silk and decapitate the target from many kilometers away without detection. The hair can also be manipulated like extra limbs, allowing for the user to grab onto their targets.
 Second Fate character popularity poll
Oh. By the way, the Noble Phantasm of every Servant Assassin is named 'Zabaniya'. The reason is that each of the 19 candidates for the position of 'Leader of the Assassins' is concealing an 'ultimate technique' crowned with the name Zabaniya -- a hidden trump card for the purpose of taking down the other 18.
初めて知った人の愛～♪ そのコタツでミカンに目覚めた男～♪ アサシンになる前は地味でのんびり屋な性格だったんでしょうかねー。きっと、お正月は臓硯の爺さんと花札やってたんですよ！ 自分たちも当然のように虎ぶるモードに出演するんだと信じて！ うう悲しすぎる、全米が泣いた……！ ところでアッ○ーの教えはどうした。 暗殺者のサーヴァント。アサシンの語源となった、とある暗殺教団のトップに立った者の一人。アサシンの頭目になった時点で自らの顔を無くした人物。 『stay night』では老魔術師・間桐臓硯に仕え、地味ながらも中々の働き者っぷりを疲労しました。派手な活躍はないものの、その戦闘スタイルはなかなかに格好いいのでは。そしてただ一人、『hollow』で出番がなかった男。あうう、全世界が泣いた……！（夜の聖杯戦争で出てきたのは真アサシンであって真アサシンじゃないしなー） あ。余談ですが、アサシンのサーヴァントの宝具名はすべて『ザバーニーヤ』です。アサシン頭目の候補は十九人おり、その誰もがザバーニーヤの名を冠する「奥義」を隠し持っているのです。彼らは他の十八人を蹴落とす為、奥の手は隠しているのだとか。
- ↑ Fate/Zero - Einzbern Consultation Room 4
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6
 Fate/complete material III: World Material - The Servants of the Fifth Holy Grail War: True Assassin, p.032-033 [T]
Master: Matou Zouken
Alignment: Lawfully Evil
Noble Phantasm: C
The legend of the "Old Man of the Mountain" appeared even in The Travels of Marco Polo. He was the head of an order of assassins who sought out promising young candidates and recruited them with promises of food, drink, and women, in exchange for assassinating important figures.
This legend had its origins in the 11th century. It originated with Nizari subbranch of Ismāʿīlism, a branch of Shia Islam. They were known as a radical sect. The progenitor of the Nizari was Hassan-i Sabbāh himself. Hassan, who had deep connections to the fallen Fatimid Caliphate, opposed the great Seljuq dynasty, repeatedly assaulting it with war and assassination. The tales of the "assassin order" in later centuries were based on this historical truth.
In the world of Fate/stay night, the name Hassan-i Sabbāh was a title among the Nizari people, whose heir would remove his or her nose and skin to become a faceless person. It is believed that the origin of the term "assassin" is either Hassan's name, or the hashish that he used as a brainwashing drug. Hassan's summoning catalyst is the Assassin class itself. For this reason, a properly summoned Assassin will always manifest as Hassan-i Sabbāh.
Hassan appears only a few times in the story. Normally, he moves stealthily, collecting intelligence per the orders of his Master, Matou Zouken. Hassan only shows himself when it is time to kill an enemy.
Hassan himself not a strong Servant. He displays his combat strength through surprise attacks, and is ill-suited to frontal assaults. Thus, Hassan waits for opportunities to arise with an invariable/absolute/certain chance of killing the target. There is no need for him to pursue the superhuman Servants. Instead, he waits for the perfect chance to get close to a Master, whom he can easily defeat...
Presence Concealment: A+
The greatest weapon of the Assassin class is Presence Containment. When this power is activated, it is possible to completely cut off one's presence. When Hassan is so concealed, it is impossible even for a Servant to sense his presence. One would not be able to tell if Hassan was approaching, if he had already left the area, or if he had even been there in the first place... Thus, Hassan is able to gather intelligence with impunity. Security systems of any kind are meaningless before him.
Also, Hassan-i Sabbāh is a being created from the nineteen people that inherited the name. When Assassin is summoned, one of those nineteen individuals will appear. Naturally, Assassin's abilities and Noble Phantasms change depending on which Hassan is summoned. However, the excellent Presence Containment skill is a class ability, so it is shared by all Assassins. As described above, each Hassan has removed his or her nose and skin to create a faceless appearance, which carries the significance of being "nobody." It is hypothesized that the anonymity of being "nobody," the elimination of the self, also influences Presence Containment's ability to "hide oneself." Incidentally, the nineteen Hassans each have unique personalities, so the reader should take care to remember that they are not emotionless fighting machines.
Each of the "Hassans" are not quite Heroic Spirits, but rather mere wraiths (Heroic Spirits are heroes that have left their names in history, and assassins have no names). In comparison to the other Servants, Assassin's combat ability is lacking. However, the discussion changes if Assassin uses Presence Containment to obtain a perfect killing opportunity. Even if the first blow fails to defeat the enemy, Assassin can conceal himself again with Presence Containment, and vigilantly await another opportunity. As a matter of fact, even the formidable Cu Chulainn was easily defeated when he faced Hassan.
Nonetheless, there are weaknesses. In the moment that the user launches an attack, the rank of Presence Containment dramatically decreases. A normal person would fail to notice the killing intent and be sent to the world beyond. However, Hassan's opponents are Servants. For example, with Artoria's Instinct, it is possible to sense the presence of a trap and respond to it. Strategic planning on the Master's part is essential to make the best use of this crafty Servant.
Projectile (Daggers): B
Hassan's main mode of attack is to throw dirks, a type of dagger that originated in Scotland. His daggers have the same destructive power as firearms when thrown, spelling certain death for a human target. Interestingly, Hassan will never fail to recover all of his thrown daggers after battle, perhaps out of a possessive quirk of personality, or an aesthetic desire to only use his favorite weapons.
Caption: Hassan silently closes in on Kotomine Kirei. Hassan threw his daggers, but Kotomine fended them off.
Protection from Wind: A
In the Middle East, there are legends that typhoons are caused by evil wind gods called djinni (alternately "jinn," "jinnaye"). Divine Protection from Wind is a chant that offers prayers to God, that oneself might receive a charm of protection against the calamity of such evil spirits. To call it a "charm" smacks of superstition, but the strength of its warding is tremendous. Hassan used this skill to resist Artoria's powerful "Bounded Field of the Wind King -- Invisible Air."
Caption: Hassan uses Divine Protection from Wind. A hidden, sacred charm is woven, and his body is imbued with its divine protection.
As its title suggests, this is the ability to alter oneself by connecting one's own flesh to another body. One can increase the length of one's legs, for example, resulting in a form far removed from that of a proper Heroic Spirit. Hassan, whose abilities are below that of the other Servants, uses Self-Modification to enhance his physical performance and make up for his deficits. In the story, he seized Cu Chulainn's heart and introduced it to his own body.
Caption: Hassan, deformed via Self-Modification. His right arm is changing into the arm of the devil Shaytan.
Maximum Targets: 1 Person
The assassination technique, "Delusional Heartbeat: Zabaniya," that uses Hassan's cursed arm. Hassan connects his arm to the arm of the devil Shaytan (Satan in Christian cosmology). This ability specializes in cursing people to death.
A mirror image is taken of the target to be killed, and from this mirror an ether clump is used to create an exact double existence. This double existence has a property of resonance with the original, so that if the double existence is harmed, the original will suffer the same damage. This can be considered sympathetic magic, albeit of an extremely high level. With this technique, an imitation heart belonging to the target is crushed, and the target dies without any outward sign of injury as its heart alone is pulverized. All armor is meaningless against Delusional Heartbeat's attack. No matter how mighty the foe, they cannot withstand this Noble Phantasm which directly assaults the inner organs. It is indeed a terrifying Noble Phantasm worthy of an assassin.
Defending against Zabaniya
Delusional Heartbeat is a Noble Phantasm of absolute death. However, as with other Noble Phantasms, it is neither invincible nor perfect.
The ability's effective range is limited, so if one retreats past this distance and uses long-range attacks, Assassin is helpless. Also, Delusional Heartbeat is a curse, so it may be ineffective against Servants with high Magic Resistance, while targets with high Luck may be able to evade it. Additionally, there is the critical fact that the heart organ is not the vital point of a Servant. There also exist exceptional opponents such as Servants that can move without a heart, or individuals that are unaffected by a destroyed heart such as Kotomine Kirei.
- ↑ 4.0 4.1 4.2 4.3 4.4
 Fate/Grand Order - Assassin Profile [T]
Hassan of the Cursed Arm - Assassin
Illustrator and Voice actor
Illustrator: Task Ohna
Voice Actor: Tetsu Inada
Noble Phantasm: C
Projectile (Daggers) B
Protection from Wind A
Presence Concealment A+
Zabaniya - Delusional Heartbeat
Type: Anti-Unit Noble Phantasm
The assassin of the white skull.
The leader of the assassination cult that had its origins in Middle East.
Also called "Old Man of the Mountain", he is one of the legendary heads of the Nizari sect that became the root word for the term assassin.
Supposedly there are 18 successive generations of the Old Man of the Mountain, and each one is said to be an expert that cultivated a special technique.
Level 1 Bond
Source: Middle East, Old Man of the Mountain
Region: Middle East
Alignment: Lawful Evil Gender: Male
His height includes the parts from body modification.
Level 2 Bond
An ominous outward appearance produced by a skull mask, a dark robe and a pole-like right arm.
The face underneath the skull mask has been scrapped off, so he is faceless. From the moment he succeeded the professional name of "Hassan i-Sabbah", everything he had until then as an individual was thrown away.
Level 3 Bond
Although it cannot be said that he is a humane good person, he is loyal to his lord's orders; he won't betray someone he has recognized as a lord no matter what sort of numerical inferiority befalls, and will silently obey even somewhat unreasonable orders. Also, he treats killing as merely an assignment, duty and does not feel any grief or pleasure from it.
Level 4 Bond
Rank: C Type: Anti-Unit
A cursed arm. The arm of the evil spirit Shaytan, it excels at cursing humans to death.
By making use of a clump of ether, a two-fold existence of the assassination target reflected in the mirror - in which both the genuine article and the opposite-mirror existence influence each other - is produced.
By crushing the fake that resonated with the assassination target, even without touching a finger on the genuine article the assassination target is cursed to death.
Level 5 Bond
- Presence Concealment: A+
Suppress the presence as a Servant.
Suited for covert operations.
If the presence is completely suppressed, it is nearly impossible to detect him.
However, once he make preparations to attack, the Rank of Presence Concealment drops greatly.
One cannot judge people by their appearances.
Upon talking, one can understand he is a character that prizes the principle of things, who approves social order.
Putting aside the abilities as a Heroic Spirit, as someone who serves others he is without question first-rate.
呪腕のハサン - アサシン
- Presence Concealment: A+
 Fate/side material - Encyclopedia: Delusional Heartbeat [Noble Phantasm, Magecraft], p.076
Delusional Heartbeat [Noble Phantasm, Magecraft]
The cursed arm, Zabaniya.
The arm of the evil spirit Shaytan, proficient in cursing humans to death.
By using an Ether Lump, Delusional Heartbeat creates a dual existence which can influence the original by generating a mirrored existence of the target.
By destroying the false copy, it curses the target to death without laying a finger on the original.
It is a type of convoluted killing technique, only fitting for assassination.
Even with a suit of armour with a defense of 1000, Delusional Heartbeat grasps the false heart right on top of the armour, and inflicts direct damage to the insides of the target.
This Noble Phantasm almost seems like a trick performed by an illusionist.
 Fate/complete material III: World material - FAQ with Nasu: Noble Phantasms, p.134
Q: Is there any way to defend against "Delusional Heartbeat: Zabaniya"?
Q: Is there any way to defend against "Delusional Heartbeat: Zabaniya"?
A: One can simply stay out of True Assassin’s range, have high enough MGI to dispel the cursed mirror image heart that Zabaniya creates, or have high enough Luck to avoid it without any problem.
- ↑ I see you obtained your arm from a demon, but it will have no effect on me as long as it bears the name of the angels of hell. - 悪魔より譲り受けた腕と見たが、地獄の天使の名を冠する以上、私に効き目はない
- ↑ 9.0 9.1 9.2
 Fate/Zero material - Servant Status: Assassin, p.022-023
Master: Kirei Kotomine
True Name: Hassan-i Sabbah
Alignment: Lawful Evil
Noble Phantasm: B
■ Presence Concealment: A+
■ Librarian of Stored Knowledge: C
■ Expert of Many Specializations: A+
■ Zabaniya：Delusional Illusion
Type: Anti-Unit (Self) Noble Phantasm
- ↑ 10.0 10.1
- ↑ 11.0 11.1 11.2 11.3 Fate/Grand Order material III - The Hundred-Faced Hassan, p.336-341
 Fate/Zero material - Encyclopedia: Hundred-Faced Hassan [Servant], p.103
Hundred-Faced Hassan [Servant]
The Assassin Heroic Spirit who participated in the Fourth Holy Grail War. One of the "Old Man of the Mountain" amongst the generations of Hassan-i Sabbah.
He was an exception in Hassans, as he did not undergo the body modification called "Zabaniya". Instead, he took advantage of his affliction of Multiple Personality Disorder and acted as an assassin without a true identity.
When summoned as a spiritual entity and emerged as a Servant, segments of his compartmentalized soul each materialized as an individual. However, due to the potential of the spirit being only that of one person, the abilities of the Assassins produced by the division were extremely low, reaching the nadir of the capabilities of Servants.
In addition, each personality has his strengths and weaknesses. Among them, there are impatient glory-hounds who ignore orders like fools, and individuals who are terrible at ambushes despite being assassins. However, if one can comprehend their characteristics and apply their skills in the right situations, the Hundred-Faced Hassan can be a very dangerous Servant. Unfortunately, because his Master had no intention of winning the war, he was damned to the fate of a voyeur.
The Hundred-Faced Hassan was summoned by Kotomine Kirei when he was still a lackey of Tokiomi Tohsaka, thus he was truly a servant of a servant. Even so, he still harboured a wish that he hoped the Grail could grant (by the way, it was "to have a perfect and unified personality"). He even plotted to hijack the Holy Grail before Kirei and Tokiomi, had the war have gone in their favour. However, in the end he did not even have a chance to show his rebellious side before becoming the first Servant eliminated from the war.
 ALL OVER/Zero - Fate/Zero Exchange of Questions and Answers, p.022-023
Questions 04: Can you give me some examples of the assassins amongst the Hundred Faced One who gave you the most enduring impressions? [T]
Questions 04: Can you give me some examples of the assassins amongst the Hundred Faced One who gave you the most enduring impressions?
Gen: It ought to be "the assassin who is famous for impersonating Toyotomi Hideyoshi".
Nasu: For me, it ought to be the assassin whose expertise is in sexing chicks.