Shisui Uchiha

, renowned as, was an Anbu from Konohagakure's Uchiha clan.

Background
At the end of the Third Shinobi World War, Shisui witnessed his best friend die, consequently awakening the Mangekyō Sharingan. A year later, he met a 5 year old Itachi Uchiha, becoming best friends and forming a brother-like bond. When Itachi began to act oddly, Shisui was instructed by the Konoha Military Police Force to monitor Itachi because the younger Uchiha's position in Anbu was instrumental to the Uchiha's future status in Konoha. Unbeknownst to the clan, Shisui in reality sympathised with Itachi, not wanting the Uchiha to go to war with the village.

In the anime, Team Shisui was assigned a long mission, which they were tasked with chasing away Kirigakure forces being lead by Ao. The team completed their mission after Ao realised they were facing Shisui and had his team retreat, not without retaining an acute memory of Shisui's chakra colour. As the Uchiha continued to grow angrier and more violent from the distrust of the village due to the suspicion of their involvement in the Nine-Tailed Demon Fox's Attack, Shisui approached Hiruzen Sarutobi revealing the truth to the Third Hokage. Trusting Shisui, seeing as he is Kagami Uchiha's descendant, Hiruzen allowed the Uchiha to spy on his clan for the village. Shisui was perplexed that the clan would not deter from the coup d'état that they were planning and soon became greatly concerned with the consequences that would follow their actions. Ultimately, it was decided that Shisui would use his Kotoamatsukami on Fugaku Uchiha to subtly end the coup d'état plan.

Later, as Shisui prepared to make his move, Danzō Shimura, believing that simply manipulating the Uchiha's leader wouldn't end the conflict and that he would eventually try to manipulate him as well, chose to take Shisui's eyes for himself in the desire to protect the village in his own way. While Shisui effortlessly subdued Danzō at first, the ruthless elder caught Shisui off guard by using the forbidden Izanagi with another Sharingan already in his possession to break free and steal Shisui's right eye. As Danzō and his men surrounded Shisui to take the left eye, Shisui managed to escape.

Fearing that Danzō was right in Shisui's inability to stop the Uchiha's revolt and that the elder would continue to pursue his left eye as well, Shisui entrusted it to Itachi, telling him to protect both the village and the Uchiha name. Shisui wrote a suicide note telling his clan he cannot follow through with the coup d'etat, but his clan's narrow mindedness made them unable to understand this, believing he would even sacrifice innocent lives for the sake of the Uchiha Clan. The contents of the suicide note also made it appear as though he had crushed his eyes when jumping off a cliff into the Naka River to kill himself in order to prevent conflict from arising over his eyes within the clan. He, at the same time, was able to erase his existence, leaving no corpse behind. In the anime, Shisui was also hoping to use his death to awaken Itachi's Mangekyō Sharingan, succeeding in the goal.

Personality
Shisui was a very humble and down-to-earth individual. He was never arrogant about his own talent or accomplishments, yet was not above telling others when they made mistakes. At the same time, he was open-minded, never stubbornly believing in one ideal solely and strived to see that unique nature of current situation before him. He was also shown to be very perceptive and intuitive even from a young age, able to see through the emotional nature of others and likewise able to notice the smallest details around him. Shisui came to care for Itachi very much; in fact, he was like a big brother to Itachi. Shisui taught Itachi that "self-sacrifice… a nameless shinobi who protects peace from within its shadow…" was the true mark of a shinobi. Shisui was also very devoted to the clan, which is why the Konoha Military Police Force asked him to spy on Itachi. It is because of this devotion that the police did not believe he could have committed suicide.

Although Shisui was devoted to his clan, he was even more devoted to the well-being of his village, a trait his own clan is apparently ignorant of. His devotion to his village was so strong that he never fell victim to the Curse of Hatred when awakening his Sharingan or even his Mangekyō Sharingan. He even went as far as to attempt to put his clan under a genjutsu in order to stop their coup d'état which would lead to civil war. However, this failed when Danzō stole his right eye. Knowing Danzō's power hungry personality would eventually lead him to steal his left eye as well, he resolved to prevent Danzō from stealing it to stop him from gaining too much power. With this in mind, he entrusted his left eye to Itachi and told him to protect the village and was able to die with a smile knowing the village would be in good hands despite all he had been through prior to his death. Shisui even went as far as to erase his own existence to prevent his corpse from falling into the wrong hands, which inadvertently prevented him from being reincarnated by Kabuto years later and being forced to fight his own village. According to Itachi, he and Naruto Uzumaki hold similar ideals and goals. Shisui also greatly valued the notion of "family" as seen when he swore to never let the clan's issues to destroy the relationship between Itachi and Sasuke. He also had a sense of humour, as seen when he enjoyed the difficult situation he put Itachi in when Sasuke argued with Shisui over who is stronger.

Like Itachi, Shisui doesn't appear to enjoy killing people and prefers to use non-lethal methods whenever possible as shown in his using a genjutsu to scare off Ao's squad when it was stated he could have killed his entire squad with ease. Shisui also used a genjutsu on Danzō, which would disappear shortly, instead of killing him when the latter tried to steal his eyes.

Appearance
Bearing stark resemblance to his ancestor Kagami Uchiha, Shisui also had short, unkempt, dark-coloured hair, black eyes and a relatively broad nose and well-defined eyelashes, that were turns upwards at each end. In the anime, however, these lines are broken instead of whole.

He wore the standard attire of the Uchiha clan which includes a high-collared, dark-coloured outfit along with a tantō strapped to the right side of the back of his shoulder. He also wore what appeared to be a harness for his tantō which ran across his chest and fastened over both his shoulders.

During his time in the regular forces, Shisui donned the standard Konoha-nin uniform.

Abilities
Even by Uchiha standards, Shisui was noted to be one of the most talented members the famed clan ever had. Danzō even hailed him as the strongest Uchiha of his time. His abilities allowed him to rise to rank of jōnin at a young age and eventually a captain of his own squad. His prowess was so widely known that an entire squad of Kiri-nin quickly chose to flee upon learning of his presence rather than to confront him. A further testament to his prowess is the fact that Kabuto Yakushi wanted to reincarnate him for the upcoming war but was unable to find a sufficient DNA sample for it.

Physical Prowess
He had earned the nickname of "Shisui of the Body Flicker" as he had great mastery of the Body Flicker Technique. Shisui would often make practical uses of the Body Flicker Technique to fade out of sight, leaving no trace of either his presence or indication of his destination. In the anime, his velocity and mobility was so great that he could leave behind multiple tangible after-images that could strike with actual force and could also move undetected by sensor ninja. In battle, his speed was shown to be able to seamlessly dodge barrages of projectiles from his enemy and likewise outpace them. He was also a proficient taijutsu user, being able to defeat Itachi in several sparring matches. Furthermore, he displayed a high level of pain tolerance as he didn't flinch from having either of his eyes removed.

Ninjutsu
Shisui was able to summon a flock of crows to aid him in battle and master three basic nature transformations (Fire, Lightning and Wind) along with the Yin Release. He was very skilled with using fire techniques such as the rite of passage Great Fireball Technique. Shisui's usage of this technique required the efforts of many Anbu-level Water Release users to counterbalance it. He also wielded a tantō, showing considerable skill in kenjutsu from a young age against two Anbu. He showed similar remarkable Shurikenjutsu-prowess to Itachi and likewise demonstrated noticeable sleight-of-hand with multiple kunai. Shisui also proved to be a very skilled tracker.

Sharingan
Like many members of his clan, Shisui was a wielder of the Sharingan, which he awakened at a young age. His mastery of the Sharingan rivalled that of Itachi's, both being highly praised for their noticeably high skill and sheer power in its usage. Using it, he gains access to the dōjutsu's generic abilities such as seeing chakra, predicting movements, and placing a victim under paralysis genjutsu with just a single glance. His genjutsu was especially powerful, hailed as the most powerful user of the clan. His most basic techniques could easily trap other powerful users of the Sharingan, like Danzō, forcing the latter to resort to using Izanagi. Shisui was also able to trap multiple individuals in his genjutsu from great distances away.

Mangekyō Sharingan
Shisui was one of the few members in the clan's history that was able to awaken the Mangekyō Sharingan. He awakened it when he watched a dear friend and rival die. Its design is a four-point pinwheel and it granted him access to a powerful genjutsu, a unique technique noted to be of the highest calibre, Kotoamatsukami. This technique allowed him to enter a person's mind and manipulate them by giving them false experiences, making it seem as if they were doing things on their own free will; the victim wouldn't even notice they were being manipulated. This technique was so powerful, Shisui believed he could use it to make the entire Uchiha clan abandon the coup d'etat.

This ability was so unique and powerful, that even Tobi wanted it for himself and was angry that Danzō managed to destroy the eye before he died. Kabuto was also extremely thrilled when he learned that the remaining eye was within Itachi's crow. Shisui's eyes were also seen as something of a treasure even within his own clan, as before his death he had to ensure that it looked like he had destroyed them before he had died, fearing it would end in conflict otherwise.

In Ninja Escapades, Shisui's Mangekyō Sharingan also awakened the ability to manifest Susanoo. His proficiency with this technique even allowed Shisui to produce and fully manifest its form shortly after having his right eye stolen. It is green in colour, when manifested had a fiendish look to it. Its defence was capable of withstanding explosive tags attached to kunai, leaving Shisui untouched. His Susanoo demonstrated the ability to unleash a barrage of chakra needles from its chest at an incredible speed.

Legacy
Throughout his lifetime and even in death, Shisui influenced Itachi greatly as a friend in teaching him self-sacrifice and how a true shinobi must protect his village from within its own shadow. This possibly influenced Itachi in his future actions to the staving off of a possible civil war within the village that may have escalated into a world war. Shisui's effort to erase his very corpse was successful as even Kabuto Yakushi noted that he was unable to locate it in an effort to reincarnate Shisui for the Fourth Shinobi World War. Despite leaving a note, claiming that he was tired of carrying out the clan's duties, the police suspected that Itachi had murdered him and used his Sharingan to forge the suicide note, since suicide was very unlikely for someone of Shisui's character. Using Shisui's death to his advantage, Itachi later told Sasuke Uchiha that he did kill Shisui to awaken his Mangekyō Sharingan and forged the suicide note, all in an effort to motivate Sasuke to kill him as repentance for his crimes.

Even years after his demise, Shisui's powers and actions left their mark on the world. While Danzō used the eye he stole for his questionable agendas to maintain their village, Itachi kept Shisui's other eye to honour his friend's final request to protect the village and their clan's good name. Inserting the eye in the body of a crow, Itachi made final arrangements to implant the bird in Naruto's body as a countermeasure against Sasuke if he learned the truth behind the Uchiha clan's demise and attempted to destroy Konoha.

However, due to the immense power that Shisui's eyes held, they were eventually destroyed to prevent them from falling into enemy hands: Danzō destroying his eye in his final moments to keep Tobi from acquiring it, and a reincarnated Itachi, after Kotoamatsukami was used on him, incinerated the crow. But Itachi also stated that above all else, Shisui wanted someone to inherit his will and ideals, believing Naruto to be that someone.

Video Games
True to his moniker, Shisui's moves rely mostly on sheer speed attacks. He is also shown using Fire Release through his tantō and kunai for more potent and longer ranged attacks. His team attack is a unified Fire Release followed by a blazing speed assault with Itachi.

In addition, exclusively for the release of this game, Shisui is able to use a green-coloured Susanoo. It wields a drill-like lance that can be used in said fashion and also in unison with Shisui's Fire Release to create a vortex of flames. It is also able to unleash a barrage of energy needles. This was designed by Masashi Kishimoto himself.

Trivia

 * Shisui's name has two interpretable meanings. Combining the words and, Shisui would mean "death water", which is a reference to his death by drowning.  alone means "still water" or "stagnant water".
 * Shisui is Kagami Uchiha's, though their exact relationship is unknown.
 * In the anime, Shisui's Mangekyō pattern is depicted as a pinwheel of four spiralling curves instead of four points.
 * Although his encounter with Danzō was unseen in the manga, it was portrayed in Itachi Shinden: Book of Dark Night novel, the anime and Ultimate Ninja Storm Revolution OVA, albeit each differently.
 * In the novel, Shisui was attacked by Danzō and Sugaru from the Aburame clan, whose insects poisoned Shisui.
 * In the anime, Danzō arranged a meeting with Shisui and stole his eye after a small scuffle.
 * In the "The Two Uchiha" story, Danzō and Root ambushed Shisui and put him into a corner until Itachi came to his rescue.

Quotes

 * (To Itachi) "I don't even know if there is such a thing as justice in the shinobi world. We fight believing in our own justice. But if the enemy is doing the same thing, who's right?"
 * (To Itachi) "…You're my best friend and the only one I can count on… Protect the village… and the Uchiha name."