Tsubame Gaeshi

is the fabled technique of the legendary swordsman who was said to be able to cut down a swallow in mid-flight. He achieved a Mystery attained only with human techniques that rivaled the Noble Phantasms of Servants. It is not something recognized as a Noble Phantasm under the Fuyuki Servant system, but rather an intrinsic Skill of the anonymous swordsman representing and using the legend of the great individual Kojiro as his source of identity. While still unranked, it is classified as a Noble Phantasm under the FATE system. This demonic sword technique, the utmost and sole technique used by Assassin, is not a Noble Phantasm or a magical phenomenon, but it has reached a level comparable to one out of pure godlike skill that "surpasses even Servants." It is a technique where three concurrent arching blades close on the enemy from all sides to create a prison, allowing no chance for defense or evasion. While he downplays it as simply successive slashes done "quickly", it is actually bending the laws of physics to multiply its existence. It starts with a flash from this world, followed by two absolutely simultaneous, over-lapping flashes that disregard the concept of time and space, producing a slash attack that arrives from three different directions by momentarily using the Multi-Dimensional Refraction Phenomenon of Zelretch's Second Magic to transcend speed, dexterity, feints, and many other elements. It is an extremely important secret technique to Assassin, who never takes up a stance, which can be seen by observing how he lifts his sword and swiftly launches the technique.
tsubamestance.jpg|Sasaki Kojirou taking the stance to use Tsubame Gaeshi
tg.jpg|Tsubame Gaeshi strikes
File:Tsubame Mai.gif|Hiken: Tsubame Mai
Saber Tsubame Gaeshi Ufotable.gif|Artoria Pendragon's expected outcome of Tsubame-Gaeshi
Tsubame Gaeshi's actual outcome (Ufotable).gif|The Actual outcome of Tsubame Gaeshi.
He has an extremely long range with his over 150 cm Monohoshi-Zao, which would normally be ineffective at close range where he uses the technique. The first strike comes at the opponent with overwhelming speed, creating a circular arc horizontally to surround them. This isn't much trouble on its own, especially with the length of the blade, but the slightly slower second vertical strike meant to block off escape from above and the third vertical strike to keep the opponent from escaping to the side completely overwhelms the opponent. It is a technique that "challenges god" with mere human skill, making it impossible to block. If one of the slashes is blocked, the other two will hit. Due to the close range, if the opponent attempts to retreat, the longsword will quickly cut them down. Assassin normally fights on higher ground to have an advantage over his opponents, but Tsubame Gaeshi requires a level foundation in order for it to be perfectly executed. If he lacks a proper foothold, he will only be able to make the first two slashes. As this technique is born of prodigious skill instead of a magical ability, it requires no additional magical energy beyond what Assassin needs to move.
Like Gáe Bolg, it is impossible to avoid, albeit through different mechanics. It is possible to develop countermeasures against Gáe Bolg after learning that it targets the heart, but the only true countermeasure against Tsubame Gaeshi is to not allow him to use the skill at all. It is possible to avoid the incomplete version with two slashes by escaping to the side, but the real technique is nearly impossible to survive. Saber, fighting with pure technique due to being unable to use Excalibur at that range, manages to defeat it after Assassin allows his sword to be damaged in order to lure her onto flat ground. Through her precognition and pure determination, she is able to see the weak point in the technique, a tiny opening between his left arm and waist. She only barely manages to avoid being cut while rushing through the opening, and the only reason it was a success was due to her experience with the technique used beforehand on her and the damaged blade. If the blade had been in perfect condition, the technique would have stayed invincible.Fate/stay night - Unlimited Blade Works route - Day 15: After image - The beauties of nature Fate/unlimited codes features a technique called , which is a series of six blinding strikes around the enemy, followed by Tsubame Gaeshi.
The process behind the development of the technique was simply Assassin attempting to figure out the means of cutting down a swallow in mid-flight. He found that swallows feel the shaking of the wind caused by the sword strike in order to avoid the blade. It is impossible to avoid disturbing the air, no matter how fast the strike, and a sword can only move in a straight line. The swallow can move horizontally or vertically to avoid it, so a single strike cannot possibly cut one down. The swallow's escape route must be completely blocked off, meaning that after the first attack, another is necessary to entrap it. The second blow cannot possibly be done in time to hit the swallow, and it is beyond human capabilities to attack multiple times in one instant. He accepted that it was impossible, but with nothing else to do as a simple and honest reason, he spent his entire lifetime practicing the sword in order to reach the pinnacle of swordsmanship until the very end. After a long period of time, he perfected the technique and it reached another state entirely.Fate/Grand Order: Epic of Remnant - Shimosa Province: The Stage of Rivers of Blood and Mountains of Corpses - Section 15: The Stage of Carnage, Onriedo (Ending) Although with some limitations, he eventually attained, perfected and refined his goal, a Mystic Sword technique as a prison of slashes that treads into the Second Magic without any knowledge of Magecraft or True Magic by doing nothing but spending his life swinging his longsword, following a single worthless idea on how to kill a flying swallow.
There is a sword of infinity that leads to multiplicity. A way to acknowledge "multiple possibilities". A single act that is originally finite; a single slash that can only be performed at one time, in one space. It is, so to speak, an "infinite" sword that gives birth to several "correct answers". To make one's own existence transparent to the extremes, till there is nothing more. And yet to grasp for "something" beyond that. That is Kojiro's "Tsubame Gaeshi". A sword that creates a "future" that not even the gods can escape from.Fate/Grand Order Epic of Remnant - Shimosa Parallel World: Chapter 15, Duel between Musashi and Kojiro, translated by anon at /fgog.
==Variations==
===Hiken - Hiyoku Senyou===
, also known as , is a technique used by Miyamoto Iori, who studied under Sasaki Kojirou. Using two katanas, he deals six simultaneous sword strikes. However with Iori’s use of a shorter katana and an even shorter wakizashi, the effective range of the technique is not as great as the original. Iori himself believes that despite its ferocity, this technique does not necessarily surpass Kojirou's original.
Iori has no recollection of whether or not he wielded this secret sword in actual battle during his lifetime.
==References==
it:Tsubame Gaeshi
vi:Yến Phản
Category:Noble Phantasms
Category:Anti-Unit Noble Phantasms
Category:Techniques
Category:Unranked Noble Phantasms
Category:Skills
Category:Mystic Sword Techniques
Category:Noble Phantasms introduced in Fate/stay night
Category:Effects on the level of Magic
Category:Swords
Category:Master's Noble Phantasms