Shin Uchiha

was a former test subject of Orochimaru. After developing a fixation on the Uchiha clan, more specifically Itachi, he took the Uchiha name for himself and severed ties with Orochimaru, taking his "sons" with him. Believing that peace was detrimental to human evolution, Shin began a plot to revive the Akatsuki so that the ensuing conflict would be a catalyst to further his beliefs.

Background
Shin was one of Orochimaru's experimental test subjects and followers, and possessed a unique genetic make-up allowed the Sannin to perform and succeed in various genetic experiments, including cultivating permanent clones. Harvesting Shin's teeth and nerves ultimately allowed Orochimaru to uncover the many secrets of genetics.

At some point Shin became obsessed with the Uchiha clan, especially Itachi. As such, he began to imitate the Uchiha: adopting their surname and customary clothing, as well as numerous Sharingan which have been implanted all over his body. His Sharingan-embedded right arm was harvested by Orochimaru and transplanted to Danzō Shimura along with some of Hashirama Senju's cells. Some time after this, Shin left Orochimaru's side and took most of his clones with him.

Personality
Shin's worldview was rather warped. He triumphed scientific advancement and was a firm believer of survival of the fittest and natural selection, believing that living organisms were slaves to their genes and existed only to survive by passing on their strongest traits to the next generation. In addition, believing that might made right, viewing conflict as a necessary component of mankind's evolution, he sought to revive the Akatsuki as a means bring an end all peace in the world, which he believed would cause the human species to stagnate and ultimately become extinct. Likewise, though he referred to his clones as sons, he had no fatherly affection for them, instead viewing them as extensions of his own life who should be sacrificed for the sake of his continued survival. He demonstrated this lack of emotion by using one of his clones as a human shield, then harvested the clone's vital organs to surgically replace his own, killing the clone in the process. In battle, Shin had no sense of honour, using underhanded tactics to win as seen from taking advantage of Sasuke's fatherly instincts and attacking Sarada, prompting Sasuke to shield her with his body.

Though typically logical, he had an obsessive fascination with the Uchiha and its history, particularly towards Itachi. Because of this, he adopted the Uchiha surname as his own, going so far as to outfit himself and his clones in the clan's customary attire. He had come to loathe Sasuke Uchiha, blaming him for the death of Itachi and bringing shame to the Uchiha clan, wishing to "avenge" Itachi by killing Sasuke. So delusional, he completely disregarded all of Itachi's own crimes against the Uchiha, rather believing that Itachi's actions were all justified and wished to "continue" Itachi's work. However, Sasuke remarked that Shin didn't understand anything about Itachi.

His overconfidence lead him to overestimate his control of situations, unaware of the actions of his clones creating clones of their own, and ultimately killed by them, based on his own belief of survival of the fittest.

Appearance
Shin was a tall and fit man with a pale complexion and no hair, as well as a horizontal scar that ran from his right temple to the bridge of his nose. He lacked any teeth and had his right arm had been amputated up to the bicep, using them for his experiments with Orochimaru. Shin had numerous Sharingan implanted all over his body: one in each eye socket, three on top of his head, one on each shoulder, one on each pectoral, one on each tricep, five along the back of his left forearm, and one on the back of his left hand. His right eyelids were held open by eight stitches, and the Sharingan housed within was noticeably bloodshot with darkened sclera.

Shin first appeared garbed in a dark, hooded cloak. He later discarded it to reveal a black, long-sleeved, high-collared shirt bearing an Akatsuki cloud emblem on both its front and back, as well as dark pants and boots. After sustaining internal injuries from one of Sakura's blows he removed the shirt and performed surgery on himself, leaving a large incision on his stomach that was stapled shut. In the anime, Shin's left leg was also severed beneath the knee during his final battle with Sasuke.

Abilities
Shin was a highly capable ninja, able to compete against the likes of a limited Sasuke Uchiha and Naruto Uzumaki. He was a talented strategist and tactician, able to plan well-ahead and adjust to the change in situations. Likewise, during his battle against Sakura Uchiha, while still recovering from his previous injuries, he was able to pressure her and seemingly would have defeated her had Sasuke not intervened.

Physical Prowess
Shin possessed a unique genetic make-up that would completely accept any new genetic material, be it tissue, organs or entire limbs, without a chance of rejection, allowing him to fully integrate it into his being. Doing so also allowed Shin to make use of any genetic modification at its full potential. According to Orochimaru, it was this very trait that made it much easier for permanent and separate entity clones of him to be created.

Shin had great endurance, able to survive the damage from one of Sakura Uchiha's punches long enough to be treated with surgery, which he performed himself while casually talking to the captured Sakura. Even more, after said surgery, he was quickly able to engage Sakura in combat with no apparent debilitation. He also apparently had a large reserve of chakra, as despite his various Sharingan appearing to be active constantly, he showed no signs of exhaustion or physical strain, even with regular and constant use of his Mangekyō Sharingan techniques.

In the anime, he proved to be very agile and coordinated, able to manoeuvre through the battlefield with easy. He was also adept in taijutsu with considerable strength, able to plough through stone and overwhelm Sakura despite her own adept fighting skills and destructively powerful attacks.

Sharingan
Shin possessed multiple fully-matured Sharingan implanted about his body. Because of his highly-adaptive body, Shin could maintain his Sharingan for as long as he pleased unhindered unlike most people not of Uchiha blood. With these eyes, he had heightened perception and was able to perform various complicated attack patterns. He also owned a mysterious creature with a Sharingan, was able to share vision with it and others, and could use his dōjutsu techniques through it as a medium.

Also with his right eye, Shin was capable of using space–time ninjutsu, with which he could create a barrier that instantaneously teleported himself and anything else within it to a location. Depending on the situation, he could manipulate the size and shape of the space affected.

Mangekyō Sharingan
Through unknown means, Shin was able to awaken the Mangekyō Sharingan. Its pattern was a large circle around the pupil with three points. Uniquely, Shin's Mangekyō pattern was reflected in all of the Sharingan on his body, as well as the eyes of his clones and spying creature. Using his Mangekyō, Shin was able to telekinetically manipulate any tools after branding them with a special mark on his left hand. Shin demonstrated refined control, able to manipulate multiple weapons at once to attack his opponent from various angles as well as perform surgery on himself. He was likewise able to manipulate his multiple targets together in unison to form a myriad of shapes for further versatility in battle, even as makeshift limbs that he could quickly adapt to. In the anime, his telekinetic power was so strong that he could even manipulate massive structures, effectively changing the terrain around them.

Medical Ninjutsu
As a medical-nin, Shin displayed advanced knowledge of human anatomy and surgery. Favouring scalpels in combat, Shin commonly used his Mangekyō Sharingan's technique to wield the tools telekinetically, expertly striking key points on the body to inhibit movement. He could also use the dōjutsu to perform surgery on himself, allowing him to replace his injured vital organs by transplanting healthy organs from his own clones.

Sarada Uchiha Arc
With the intent to eliminate the "disgrace" of the Uchiha clan, he tasks one of his clones to spy on Sasuke Uchiha. After his failed assassination, Shin returns to his father. After finding out that Sasuke's daughter, Sarada Uchiha, had left Konohagakure, he orders the clone to abduct her. Later after the Shin-clone returned following his failed abduction, Shin prepared to begin their next attack and called forth six Shin-clones, before teleporting with Shin to the Ridge Tower. The two arrived above Naruto and Sarada and attacked. After Naruto repelled the attack, Sasuke confronts the two.

Immediately, Sasuke faced off against Shin and repelled his blades. Before Sasuke could cut Shin with his sword, Shin caught and marked it. One of Shin's clones took the opportunity to attack from behind only to swap positions with Sasuke before he launched a fireball towards them. Without hesitation, Shin launches the clone in front of the fireball to shield himself from the flames. Applauding Sasuke's dōjutsu might, Shin announces his desire to make it his own and introduces himself. Having earlier marked Sasuke's sword, Shin manipulated the weapon and stabbed Naruto with it and launched another attack aimed at Sarada, only for Sasuke to shield her with his body. As Shin prepared another attack, Sakura arrived and delivered a devastating blow in retribution for her family being attacked.

Badly injured and prime to be captured, Shin's spying creature came to his aid and teleported him, his clone and Sakura back to their base. Upon arriving, he struck down his burnt son. Afterwards, he prepared himself for surgery, ready to have his still alive son's organs transplanted into himself as Sakura watched. He revealed to Sakura that that was not his son but only his clone. Around him more clones of himself appeared. He told Sakura that they were supposed to act as 'Stock to be used as flesh'. He revealed that he was in fact one of Orochimaru's experiments. He tells Sakura that there is no reason to be sad because all living things eventually die. They then go on to argue about the ethics of using cloning for organ transplantation. Once completing his procedure, Shin firmly announced his desire to do away with inferior genetics and concepts of peace, to which Sakura decided to attack.

Shin quickly manipulated countless scalpels as a makeshift arm as he prepared to attack. He was, however, caught by surprised by Sasuke's timely arrival, who in the manga, crushed the wannabe-Uchiha's body with Susanoo. In the anime, Sasuke's Susanoo severed Shin's right leg. As Sasuke prepared to fully subdue the opponent and bring him back to Konohagakure for questioning, a Shin-clone got in the way. As Sasuke hesitated to strike down the clone due to Sarada's feelings, Shin impaled Sasuke by using the clone as a cover, striking down the clone in the process. Shin then struck to finish Sasuke, but he swapped positions with Sakura, letting her deliver a solid blow, crippling the foe again. Realising he needed to retreat, Shin called for his clones to distract Sasuke and his allies. To Shin's horror, the clones instead stabbed him, plainly explaining that he is not needed any more. While the clones began battling against the Konoha-nin, Shin began to teleport and attempted to take the young girls with him through his creature warping them. Sarada, however, acted quickly and destroyed the creature while Shin succumbed to his injuries.

Trivia

 * In Japanese, a number of characters are pronounced as "Shin", among them being or, contributing to the initial mystery of the character's connection to the Uchiha clan.
 * On the cover of Volume 73, Shin's left eye sclerae is black.
 * In Boruto episode 21, when Shin is seen kneeling after falling to the ground, he is erroneously seen with two hands.
 * Throughout Shin's appearances, there have been various inconsistencies on the number and locations of Shin's various Sharingan, most noticeably on his left arm.

Quotes

 * "Peace means an end to evolution for humans, that's exactly what you all are."
 * "Species without evolution are eventually destroyed."