Seven Ninja Swordsmen of the Mist

The was an organisation consisting of only the greatest blade-wielding shinobi of their generation that Kirigakure can produce. There can only be seven members at a time — hence the name. The swords of the Seven Swordsmen are passed down from generation to generation.

History
Some time after the Third Shinobi World War, the Seven Swordsmen of the time (Fuguki Suikazan, Jinin Akebino, Kushimaru Kuriarare, Raiga Kurosuki, Jūzō Biwa, and two others) cornered a Konoha team. The team was rescued by Might Duy, who fought all seven using the Eight Gates Released Formation. The fate for most of the members afterwards is unknown.

The group's make-up would change over the years: Mangetsu Hōzuki joined and mastered all seven swords; Fuguki was killed and replaced by Kisame Hoshigaki. But as Kiri descended into the years of the "Bloody Mist", its members started dying — as in the case of Mangetsu, or becoming missing-nin and taking their swords with them — as in the cases of Kisame, Zabuza Momochi, and (in the anime) Raiga. By the time of the Fourth Shinobi World War, only Hiramekarei remained in Kiri's possession, wielded by Chōjūrō.

The "strongest" generation of the Seven Swordsmen is reincarnated to fight for Akatsuki during the Fourth Shinobi World War. Five of the swordsmen are reunited with their former swords, which they use against the Third Division. Although the Third Division suffers numerous casualties, they are able to seal all of the Seven Swordsmen by the second day of war. They are later released from the Impure World Reincarnation and their souls return to the Pure Land.

Swords

 * A giant sword with a butcher-knife-like appearance, the wielder can use the semi-circle on the blade to decapitate an opponent's head, hence the name. The sword has an ability to regenerate using the iron absorbed from the blood of those it cuts down. It is also called a.
 * The most terrifying of the seven blades, it has the appearance of a giant knife covered in shark scales. It is a sentient, living weapon and has the ability to "eat" chakra. It is also called a.
 * A sword in the shape of a needle with a long thin wire that resembles thread attached to it, which can be used to pierce enemies and "sew" them together in human bundles. It is also called a.
 * A sword consisting of a single sided axe and a hammer joined by a length of chain. Said to be capable of crushing any and all defences. It is also called a.
 * A sword that has a scroll full of explosive tags incorporated into it, lined up behind the blade, combining swordsmanship and explosions. It is also called a.
 * Twin swords that are imbued with lightning which increases their cutting power. They are said to be the sharpest swords ever forged. They are also called.
 * A bandaged double-handled sword that is capable of storing and emitting the user's chakra which can then take on various forms. It is also called a.

Known Members
An earlier generation of the organisation consisted of Fuguki, Jinin, Jūzō, Raiga, Kushimaru and two other unidentified shinobi:


 * Hiramekarei's wielder: A shorter individual with moused-up hair who wore his forehead protector as a choker and a utility belt around his waist along with a flak jacket and a pinstriped shirt and pants. He carried the Twinsword strapped to his back horizontally.
 * Shibuki's wielder: A slender man who wore a pinstriped shirt and a cloth-mask that only showed his eyes.

Trivia

 * It seems to be a tradition for the members and aspiring members of the Seven Swordsmen to have sharpened teeth.
 * All the known named members also have fruit-derived surnames, or if lacking a surname, their given name. This does not hold true for Raiga.
 * All of the reincarnated swordsmen have bandages around their necks.
 * At least three (four in the anime) of the members became missing-nin, while one was discovered to be a traitor, leaking confidential information to other villages.
 * Although Mangetsu was said to have mastered use of all the swords, other members of his generation wielded six of them, leaving Hiramekarei as the blade he likely primarily used.
 * Three members of the Seven Swordsmen were former Anbu members.
 * Three members of the Seven Swordsmen managed to fake their own deaths or regain life later on, by the means of an accomplice.
 * In the anime, Kushimaru and Jinpachi were known collectively as the due to their many acts of cruelty in their lifetime.