Assassin (Fate/stay night)

Assassin (アサシン) is the Assassin-class Servant of Caster in the Fifth Holy Grail War of Fate/stay night. He is an irregular Servant that shouldn't exist according to the rules of the Holy Grail War, but Caster's unique nature as a Servant summoning a Servant twists the process. The true Servant, one of the Hassan-i-Sabbah, is summoned as True Assassin in the Heaven's Feel route.

Identity
Assassin's supposed identity is that of the mythical Japanese swordsman, Sasaki Kojirō (佐々木 小次郎) whose real name was speculated to be Tsuda (津田). His true name was unknown, and to be more specific, he never had a true name. Kojirou is known as a master swordsman whose existence is doubted even though his name remains recorded in history. He did not actually exist, so it would be impossible to summon the real thing as a Servant. The person summoned in his place is not a Heroic Spirit, but an existence closer to that of wraiths. If there was to be a database for all of humanity, he is the piece of data that best matches the parameters of Sasaki, so his personality would become Kojirou's personality and his monumental feats would become that of Kojirou rather than his own.

He was a nameless martial artist with some relation to the Ryuudouji Temple, but there is no way to know his true identity. He died lacking a name, never even fortunate enough to be given one, and the ability to read or write. He utilizes a long Japanese katana and discovered the ultimate technique, “Tsubame Gaeshi”, being absolutely all he possesses. The reason he is summoned is simply because he can execute that legendary technique. He spent much of his life simply trying to figure out the best method to cut down a swallow, and although he realized the method was impossible for a human, he had nothing else to do and kept on practicing. While determination is normally the key to success, he simply noticed that it had succeeded.

The legendary Kojirou is known as cool and elegant, so Assassin's pursuit of sword technique, sophistication, and finding joy in dueling with strong foes is reminiscent of that character. Differing from the legend, his katana is longer, 1.5 meters compared to 90 centimeters and engraved with Bitchu Aoe (備中青江). With any great deed performed by Assassin, the reward will go to "Sasaki Kojirou", as he is nothing and all his actions are meaningless. He is a disposable swordsman meant only to act out the role of Sasaki Kojirou, a fictional swordsman created from a fictional story.

Legend
While the Kojirou in the modern era is an invention, a blend of details from the lives of many nameless and forgotten historical swordsmen, he is said to have been born in the in the  countryside according to records. He studied under the originator of the Chujoryu kodachi style,, favoring a long sword. He defeated the master's younger brother, and named his own style "Ganryu." He was known as a handsome swordsman wielding the 3-shaku-long, approximately 90 centimeters to one meter,, “Bizen Osahune Nagamitsu”, that was also called the “Monohoshi Zao."He traveled around the country as a master swordsman, and it is said that he developed his secret sword technique, Tsubame Gaeshi, able to kill even a flying swallow, around the in the.

He terrified swordsman around the country after that period, and eventually battled at  to maintain the reputation of the domain he served, dying in the process. He was unable to fight while holding onto the sheath of his sword due to its length, so he threw it away in front of Musashi. Musashi is quoted to have said the famous lines "Kojirou, you lose. If you're were planning to win, why did you throw away your sheath?" and “Kojirou has been defeated!" after seeing that event. The finale was of the battle was Kojirou's death after having his forehead crushed by an oar.

Musashi was one of Japan's best swordsmen, and Kojirou is known as Musashi's worthy rival. It is claimed that he gained fame around the period from the 10th to 17th year of the, but his real figure is hazy like the moon on water. Any truth of this era is a mystery due to all books noting him being inconsistent in terms of years. His duel is legendary, and although he was said to be the disciple of Seigen, there are numerous conflicting documentations and legends, which still shroud his true identity even now. The only one who should know of the existence of such a swordsman would have to be the supposed rival who defeated him, Musashi, but he is not mentioned at all in the book Musashi wrote, "."

Kojirou was a Japanese man without any real identity, his birth is unknown, and his story was only told through world of mouth. His past was falsely forged as a convenient foe to a famed swordsman. The records are too vague, but it was likely there existed man named Sasaki Kojirou and a man who wielded a sword called the Monohoshi Zao. The would not have been the same person, so the swordsman with the name Sasaki Kojirou was simply a fictional character created to be his enemy's foil. Even if there was a person like him, it can be said that his figure passed down to the present is a fictional swordsman nor an overstatement to say that he has never existed.

Personality
Assassin is quiet and composed, always maintains a degree of and and is eager to spar with other Servants. He cares little for the Holy Grail, and outside of his duties to Caster, he only seeks to enjoy a decent sword fight. He truly dislikes his master, and he won't hesitate to kill her. It is revealed in Fate/Unlimited Codes that upon his summoning by Caster he refused to be ordered around by a woman, and as a result Caster used a Command Spell to force him into obedience. The Servants are suppose to hide their true names and their powers, but he told Saber who he was when they first met. He always admired the beauty of nature and also the moon.

Appearance
Assassin's appearance is that of a samurai swordsman with long indigo hair tied into ponytail and indigo eyes. He wears a traditional light purple umanori hakama and kimono, light purple tabi and black geta with purple haori and tekkou and carries his sword, Monohoshi Zao on his back.

Fate/Stay night
Caster borrowing the power of the Greater Grail was able to obtain fake Command Spells and she managed to summon a fake servant. He was summoned as a guardian and watchman for the front gate of the Ryuudouji Temple. As an improper servant, Assassin is entirely dependent on Caster for mana and cannot move freely beyond the grounds of Ryuudou Temple. Furthermore, he lacks most of the usual parameters and abilities granted to his class. Because of his limited status, Assassin cares little for the Holy Grail, and outside of his duties to Caster, he only seeks to enjoy a decent sword duel.

Fate
In the Fate scenario, Assassin drives back Saber during her first assault on the Ryuudou Temple. During their second meeting (anime only), he allows Emiya Shirou and Tohsaka Rin to pass in order to engage Saber in a duel in which he is defeated. In the Visual Novel he is never seen after his initial confrontation with Saber. He is defeated at some point in the story but it is only mentioned and not shown leaving the identity of his killer unknown.

Unlimited Blade Works
In Unlimited Blade Works on the last night of the Holy Grail War, Saber went to the front gate of the Ryuudouji Temple to fight against Gilgamesh however Assassin still exists and wanted to duel against Saber. He is defeated by Saber due to his blade being bent from their previous encounter, which leaves an opening in his Tsubame Gaeshi.

Heaven's Feel
In the Heaven's Feel scenario, Assassin is killed by the entity known as the shadow and his flesh serves as Matou Zouken's catalyst for summoning the True Assassin.

Fate/hollow ataraxia
In Fate/hollow ataraxia, Assassin remains bound to the Ryuudou Temple, and continues to watch over its front portal even though peace has settled over Fuyuki City. He converses with whoever is kind enough to climb up the steps to see him. Incidentally, he takes upon the pseudonym Kojirou Tsuda (津田小次郎).

When Avenger makes his move, Assassin fights the dog-shadows right beside his Master, Caster and Souichirou Kuzuki.

Fate/Prototype
Assassin retains his identity from the original novel version of Fate/stay night, but he doesn't appear within the Fate/Prototype animated special.

Carnival Phantasm
Assassin has minor appearances in Carnival Phantasm. The fact that he cannot go outside the temple is comically exaggerated and even at the ending, he is represented by a cardboard cutout.

He is shown to be very attached to his gate, to the point he even talks to it, and apparently hears it talk back.

Abilities
Assassin is an irregular Servant that should not actually belong to the Assassin class, and he is considered to be strange compared to most other Servants by Saber. Out of all the other Servants she has seen, he seems incomprehensible to her, but not out of having fearful aspects or a fearful weapon. Her unease comes from not being able to sense any magical energy or even a Noble Phantasm, that it should be easy enough for her to end the match in one blow. Nothing special can be felt from his sword, so it should be easy for her to repel it. While she wishes to rush in and be done with it, her honed instincts can sense his ability to seize a sure kill, so she remains cautious of him.

He is very untypical as an Assassin. Servants in the Assassin class are normally the weakest ones in direct confrontation, and they defeat enemy Servants through covert actions or by killing their Masters to cut off their prana supply. Assassin does not employ assassination techniques such as ambush, and due to excelling in swordsmanship, he frequently chooses to fight face-to-face directly with other Servants. He does not gain the class ability of Presence Concealment due to not being a true Servant Assassin, but he does have the ability on his own. It is his intrinsic ability as a martial artist to “cut off his presence”.

Caster is unable to act as his anchor to the world due to also being a Servant, so he is instead bound to the land. The mountain itself acts as a host from the current age to keep him in the world. While that means that he cannot leave the mountain, it also means that he will not disappear even if his summoner dies. He can only appear on the mountain, and he will continue to exist as long as the mountain exists. He is not receiving constant magical upkeep, so he was only given twenty days worth of energy. He manages to go slightly longer than that limit in order to fight Saber, it is mostly luck that allowed that to happen. He begins to turn transparent, and will not last until dawn of that day.

Combat
He is an oddity that fights under different battle conditions from other Servants, a "Saber-class defender", making him defensive compared to others being offensive. Fighting on the temple stairs gives him a higher position than his opponent, and due to the area being a Servant-killing battlefield and having Caster's anti-sorcery defensive barrier, the power of both magecraft and Noble Phantasms are decreased significantly. If the Noble Phantasm being used isn't powerful, he will not take a fatal wound. He does not have any defense against curses, so he will likely instantly lose against such Noble Phantasms. This allows him to repel the other five Servants without losing any ground, though he required both the terrain advantage and Caster's help in weighing down Berserker's body to repel him. Assassin has no actual way of hurting him and they have extremely bad compatibility in a fight, so the fact that Berserker was even pushed back is enough to say "whoah, Kojirou's amazing."

While he would fall to other Servants in an all out death match, he reigns supreme on the stairs of the temple due to most battles having to come down to swordsmanship. The attacker is constantly at a disadvantage because they have to ascend the stairs to reach him, while he does not have to move if he does not wish. He has no need to chase a retreating enemy in a battle of defense, so he has no reason to forsake his advantage of higher ground. His excellent skill and the disadvantageous ground keep the opponent from being able to dodge his fatal strikes as they wish. His strikes that aim for the head means that they must retreat instead of press forward, but the terrain of fighting on the stairs leaves them unable to dodge to the side. They are left retreating to the same spot, all the while he has no need to move from his position unless he wishes to unleash his ultimate technique.

Even without Battle Continuation, he will be able to last longer with more serious wounds due to having a strong spirit alignment. Like Lancer, he will have some fighting power left even if his heart is destroyed, allowing him to close the gap between an opponent after receiving a fatal wound, such as True Assassin using Zabaniya to kill him, and use Tsubame Gaeshi to leave both of them dead. Caster placed a curse into his body upon summoning, allowing her to have his chest explode from within at her leisure. Even though his ribs are protruding from his chest, he is still able to act without fading away and later heal.

While his Presence Concealment is not a match for the Presence Concealment of True Assassin due to not being a skill trained for assassination, it allows the martial artist to merge with his surroundings. It is not a skill meant to hide someone, but a technique of the mind that allows him to cut off his presence enough that he is hard to detect even for a Servant. It is very difficult to perceive him during the first encounter, but his activity being limited to the range of the Temple Gate makes detecting him rather easy for those who know of his existence. The ability is rarely used for its intended purpose, as is personality makes it so that battles are usually only commenced only after the parties have presented and introduced themselves.

Swordsmanship
Assassin wields the Monohoshi Zao (物干し竿), an over five shaku long, 150 centimeter, Bitchu Aoe blade. The length defies common sense, the name being a derogatory nickname rather than a formal title, meaning “That blade is way too damn long to use!” It cannot be called "useful" despite its large range, as almost nobody except Assassin, having a mastery of the sword exceeding the realm of humans, could even wield it. He is noted as the greatest in terms of pure swordsmanship among the Servants of the Fifth Holy Grail War, and not even Gilgamesh would want to face him in a battle of swordsmanship. Lancer comments that he wouldn't like fighting him one on one and would prefer to kill him off from a distance.

He calls his sword a heresy, and says it will slice the head of one of average skill. He has no actual stances, meaning any seeming opening cannot be trusted, and the ability to use a sword of such length means that he has to be able to swing it from any position, even delivering slashes even while standing idly. The katana is a longsword not suited to direct competitions of power. It will break fighting off a sword like Excalibur, so he cannot lock blades or compete in strength. He can only parry blows and push the opponent back by attacking their body because the blade is meant to cut with speed and technique unlike western swords that cut with weight and power, making fighting styles between the two mismatched.

His swordplay is fast enough that even Saber has trouble following it. He works his sword like a hurricane, using elastic tracks to parry blows from opponents stronger and faster than himself, all while flowing toward the opponent's neck to decapitate the them with certainty should he detect an opening. Each of his attacks is fatal, meant to take the opponent's life by decapitation, so it is not possible to employ a strategy like taking a strike to then overpower him during the aftermath. He strikes with a curved path, a graceful arc that does not take the shortest route to the opponent like Saber's western sword. It would normally be that he should not be able to match a sword moving in a straight line and the length of the sword should make it easy to go inside his range after it is parried, but his sword techniques and Eye of the Mind, or simply dodging, allow him to counters the opponent’s attack and reduce the difference in distance to zero.

It is not possible to get used to his fighting style no matter how many times he utilizes the same technique on a single foe due to his Knowledge of Respect and Harmony skill. It is the ability to “render one’s attacks unreadable to the enemy”, so even Saber's high Instinct cannot adapt to his fighting style after crossing blades many times. Its effect vastly improved with his unique “head-shot” techniques, so the opponent will not be able to see through his techniques even after retreating and challenging him again numerous times, always forced back to square one and fought as if it is the first encounter again.

He cannot be emotionally overwhelmed in battle due to his Vitrification skill, a mental state called a “heart of clear water” that was acquired after reaching the pinnacle of arduous training. He is able to maintain a cool and collected heart, regardless the situation. Facing his own death will not cause him to waver, so it is a very useful ability for a gate guardian. Mental interference from charms and fear magecraft activated by the opponent are completely negated. He watches the gate in silence with a heart of clear water, like the many trees surrounding the temple and an unwavering guardian.

The perception of his eyes is the best among Servants, allowing him to see through the weapon and style of his opponent after crossing blades only a few times. He initially has trouble with Invisible Air because its distance cannot be gauged, making it too dangerous to close in and not allow him to follow through with his strikes. He eventually becomes able to judge its exact measurements without using magecraft or even exchanging actual blows with the sword. He is an unorthodox sword-user who is only able to improve on such techniques, so he mentions that figuring out the shape is "just a street performance." It stems from his Eye of the Mind (False), a sixth sense that very different from Archer's danger avoidance that originates from “predictions augmented by experience”. Assassin's ability can be called a natural talent to sense danger. It also allows him to see that Saber is unable to use her Noble Phantasm attack due to a lack of energy.

While Saber believes that he will lose any advantage by relinquishing his advantage of being overhead, she is misunderstanding his skill. From such a close distance, an opponent should be able to easily outmaneuver his longsword to get inside his range, but such logic does not apply to him. His secret technique, Tsubame Gaeshi, is three simultaneous sword slashes in mutually exclusive directions that can only be performed on flat ground. It is not a Noble Phantasm, but it has reached a similar level out of pure godlike skill. It should be unavoidable as long as there are no errors in its execution, making it a deadly technique. It makes him, who should be a "mere human", equal to Heroic Spirits armed with Noble Phantasms.

While he holds out the thought that his sword may be able to block a few strikes from Excalibur, it is bent only after one clash. While it is a good sword able to cut steel, something made by a human cannot compare to something not made by men. He utilizes the method to force Saber onto flat ground to utilize Tsubame Gaeshi, but it proves to be his undoing due to the bend in the sword allowing for a gap for Saber to escape from the technique.