SHARINGAN
The Sharingan (写輪眼?, lit. "Copy Wheel Eye", English manga: "Mirror Wheel Eye") is a genetic eye technique that naturally occurs in members of the Uchiha clan. It is not immediately present from birth, and first activates in a stressful situation in battle; after this occurrence, the user may utilize the Sharingan freely.[47] When first acquired, the Sharingan has only one tomoe, and as its power increases, two additional tomoe will eventually appear. Kakashi Hatake possesses a single, transplanted Sharingan in his left eye that he received from his teammate, Obito Uchiha.[48] Because he is not a member of the Uchiha clan, Kakashi's Sharingan is always active and he expends chakra rapidly when using it, forcing him to cover it up when not in combat and needing extended rest after long battles.[49] Members of the Uchiha clan expend a negligible amount of chakra when using the Sharingan; Akatsuki member Itachi Uchiha keeps his Sharingan activated constantly. Danzo has also been shown to have a Sharingan in his right eye and a multitude in his right arm.
Over the course of its development, the Sharingan will grant the user three unique abilities. It is most famous in the Naruto world for its ability to memorize and replicate any movement it has seen, allowing the user to copy most opponent's jutsu by memorizing the handsigns/muscle movements and allows them to use the jutsu against them and later opponents.[50] The Sharingan's second ability grants the user increased clarity of perception, allowing them to track and predict the movements and actions of fast-moving objects. This also allows the user to easily recognize genjutsu and different forms of chakra.[48] Its final ability is a brand of hypnosis that suggests actions and thoughts to the opponent, acting as an effective way to produce genjutsu or implant memories in another person.[51]

MANGEKYO SHARINGAN

The Mangekyo Sharingan (万華鏡写輪眼, Mangekyō Sharingan?, lit. "Kaleidoscope Copy Wheel Eye") is a heightened form of Sharingan introduced towards the end of Part I. At that time, the Mangekyo Sharingan is explained to be rare among the members of the Uchiha clan, present only in those who have killed their closest friends.[52] In Part II, this is revealed to be false; after Madara Uchiha became the first to awaken his Mangekyo Sharingan, it became common practice for Uchiha clan members to kill their friends to gain their own.[53] It is also revealed that the Mangekyo Sharingan does not need to be gained by killing a friend; instead, it can be activated after the death of anyone the user is close to. Sasuke Uchiha gains his own Mangekyo Sharingan when his brother, Itachi Uchiha dies.[54] Unlike the regular Sharingan, which appears identical from user to user, the Mangekyo Sharingan's tomoe seal differs between individuals. Similarly, each Mangekyo Sharingan grants the user unique abilities.[55] Its abilities were usually derived from the Japanese mythology. Hence, giving the interpretation that they are one of the divine and most powerful ninja techniques ever used. One feature shared by all Mangekyo Sharingan, however, is the ability to control the nine-tailed demon fox. Other known features of the Mangekyo Sharingan are Amaterasu (天照?), the ability to generate a black flame so hot that it can eat other flames when it is focused on the focal point of the eye; Tsukuyomi (月読?), a genjutsu that traps the opponent in a realm controlled by the user; and Susanoo (須佐能乎?), a summoned mystical being made of chakra which is able to protect and attack for the user. These abilities are only present in Sasuke Uchiha, and his brother Itachi Uchiha, who first derived these powers and transferred them to Sasuke at the moment of his death. Another technique, Kamui, awakened in Kakashi's Mangekyo Sharingan, which grants him the unique ability to open small dimension rifts that are capable of sucking in whatever Kakashi looks at with his Mangekyo Sharingan. Once it has been gained, the user suffers from ever-deteriorating eyesight, a process that is aggravated by repeated use and culminates in blindness.[56] One's eyesight can be permanently restored by taking the eyes of someone else who has the Mangekyo Sharingan, a process that fuses their two Mangekyo Sharingan into one "eternal" form with increased power; the only two confirmed users of the "eternal" form are Madara Uchiha and Sasuke Uchiha, but only the eternal Mangekyo form can control the demon fox and give the user the power to phase parts of his body in other dimensions and return them again to avoid most of attacks.

BACKGROUND

Sasuke's early childhood, as told over the course of Naruto manga volume twenty-five, was spent not being able to catch up to his brother, Itachi Uchiha, a natural prodigy of the Uchiha clan whom Sasuke looked up to and admired. In an effort to win some recognition for himself, Sasuke trained diligently to win some of his parents' attention, though he was never able to surpass the milestones set in place by his brother, who would be the only one to acknowledge Sasuke's accomplishments.[16][17] In time, Itachi began to distance himself from the clan and fell out of his family's confidence, which consequently began to look to Sasuke as the new future for the clan.[18]
Soon after Sasuke started to be accepted into his family, he returned home one day to find the streets littered with the corpses of the Uchiha clan. Upon rushing home, Sasuke found Itachi standing over his parents's corpses. As Sasuke tried to flee, Itachi went on to explain that he had never loved his little brother.[19] Claiming that Sasuke was not worth killing, Itachi encouraged him to get stronger by living a life of hate and anger towards him, with his sole purpose being to avenge the clan. Itachi left, and in the absence of a loving family Sasuke agreed to do as instructed, dedicating his life to killing Itachi.[20] After the massacre, Sasuke is brought up pampered and without normal problems, and to believe that he was the best merely because he was an 'Uchiha'. Years later, in Part II of the series, Sasuke is shown to have some doubts about the events of that night. It is not until after Itachi's death that he learns the truth surrounding the massacre of the Uchiha: that it was all done on command by the village, and that Itachi had left him alive because he could not bring himself to kill him.[21]

PERSONALITY

When first introduced during his assignment to Team 7, Sasuke displays a great brooding skepticism to his teammates. Feeling that his abilities are far superior to their own, he is unwilling to cooperate with Naruto Uzumaki or Sakura Haruno, as doing so would apparently do nothing to help him kill Itachi.[22] These perceptions are quickly proven wrong, for despite their failings, Sakura is a useful spout of information; while competition with Naruto acts as an effective way to get stronger.[23] While he retains a conceited arrogance in himself throughout the series, Sasuke increasingly relies on his team over the course of Part I. As he starts to get close to others he also begins to risk his own life to try to save them, even though his death would leave him unable to fulfill his goal of vengeance upon Itachi.[24]
Although Sasuke becomes content with a life of happiness in Konohagakure as well as developing a relationship with Sakura Haruno, he never allows his ambition to gain power to leave his thoughts, always keeping them as a dark muttering. During his Part I battles with characters such as Haku and Gaara, Sasuke arrogantly tests his abilities against those of progressively stronger ninja, in the process discovering the weakpoints he needs to overcome.[25] While initially complacent with his development, Naruto quickly starts to compete to grow stronger at a faster rate. This, coupled with his humiliating and effortless defeat by Itachi during a brief return to Konoha, leads Sasuke to believe that his growth is too slow. In an attempt to reassess his strength, he begins to treat his friends as opponents so as to test his abilities against their own.[26]
Dissatisfied with his progress and growth while in Konoha, he betrays Konoha in order to accept the offer of tutelage from Orochimaru at the end of Part I.[27] Naruto attempts to stop him, but Sasuke, believing the death of Naruto, his closest friend, will give him the power he desires (as he was told by Itachi), tries to kill him instead.[20] He is ultimately unable to follow through with this idea, because he felt he'd be no better than like his brother, Itachi, and instead shamelessly continues on to Orochimaru.[28] In the two-and-a-half years he spends with Orochimaru, Sasuke's goal to kill Itachi takes precedence above all else; he even claims he is willing to give his body and soul to Orochimaru if it means killing Itachi,[29] but later turns on Orochimaru after reaching the conclusion that he can learn nothing else of value.[30] After achieving his goal of bringing about Itachi's death, in the process learning how his brother was ordered by Konoha's higher ups to perform the murder of his clan, Sasuke abandons all of his hate for Itachi and resolves to kill Konoha's higher ups for his revenge,[31] to the point he is willing to kill anybody who may stop him.

ABILITIES

Sasuke has always been able to grasp most ninja abilities with ease. When Naruto begins Sasuke is highly proficient with the Uchiha clan's signature fire-breathing and weapon-based techniques,[32] talents he continues to hone throughout the series. Of the abilities gained through his Uchiha lineage, Sasuke most commonly uses the Sharingan, an ability manifested through the eyes and allows the user to see a small amount into the future. Sasuke's Sharingan develops for the duration of Part I, first only allowing him to track fast-moving objects[33] and steal jutsu, culminating with his ability to predict the movements of others.[34] In Part II he starts to use his Sharingan to cast illusions, allowing him to manipulate and confuse others.[35] Sasuke's Sharingan reaches its peak after Itachi's death; through the death of the person closest to him, Sasuke awakens his own Mangekyo Sharingan,[31] gaining most of Itachi's techniques.[36] However, he quickly pushes his Mangekyo Sharingan to its limits and, almost completely blind, has Madara transplant Itachi's eyes, giving him the perfected Mangekyo Sharingan.
Orochimaru's influence is also a recurring element of Sasuke's abilities. During their first encounter in Part I, Sasuke is branded with a cursed seal, which grants him a brief surge in strength and speed when active.[37] Sasuke's various uses of the seal cause him to crave more of its power as he enters to a second level amplifying the effect and drastically changing his appearance.[38] Itachi removes Orochimaru and the cursed seal from Sasuke's body during their final battle.[21] When Sasuke begins to train under Orochimaru, his physical abilities are greatly enhanced[39] and he learns how to summon snakes and then birds to help him in battle.[40] In addition to the techniques taught to him, Sasuke gains access to some of Orochimaru's more common abilities during the period he absorbs him into his body; Sasuke is able to recover from injuries in short periods of time and can regurgitate new bodies for himself.[41]
Prior to Sasuke's defection, his teacher, Kakashi Hatake teaches him how to use the Chidori, a collection of lightning-based chakra in his hand that serves as a rapid thrusting attack that severely damages any target.[26] While Sasuke is able to use the Chidori twice per day during Part I, his usage of the attack in Part II is unknown.[42] Instead, Sasuke employs variants of the technique, using the fundamentals behind the Chidori to create a number of new abilities. Sasuke's first display of such an ability involves emitting electricity from his body as a shield and then sending it along the blade of his chokutō to increase its cutting potential.[43] He later proves able to mold electricity into more solid forms such as extendable swords,[30] and invents a jutsu where he does not use any of his low chakra store, and using actual lightning in an attack named Kirin (麒麟?, Qilin).[44]

Character outline
[edit] Background
For much of the series, the only information given about Itachi's background is what his younger brother, Sasuke Uchiha, knows or remembers, as is chronicled in volume twenty-five of the Naruto manga. He grew up as the child prodigy of the Uchiha clan, establishing milestones for Sasuke and future Uchiha to live up to.[10] Over time, however, Itachi began to distance himself from the clan, acting hostile towards its members when he is accused of murdering his clansman Shisui Uchiha and prompting his father to discourage Sasuke from following in Itachi's footsteps.[11] Itachi soon afterwards killed every member of the clan with the explanation that he was testing his potential. He spared only Sasuke, who he claimed was too weak to be worth killing, and challenged him to live a life of hate so that he would get strong enough to someday pose a challenge to Itachi. Itachi vanished into the night, leaving Sasuke with the motive for revenge that drives his actions for most of the series.[12]
Towards the end of Naruto manga volume forty-three, after Itachi's death, the truth of his background is given in full. Itachi's early childhood was marred by war, the violence of which caused him to seek peace at any cost. When years later the Uchiha clan began planning a coup d'état to take control of the village of Konohagakure, Itachi feared the attempt would cause another war and became a double agent, providing Konoha with intelligence on his clan's actions. The village eventually gave him the mission of assassinating the Uchiha, a task he asked Madara Uchiha for assistance with. After the Uchiha were eliminated, Itachi, tormented by his actions, could not bring himself to kill Sasuke too.[13] He made himself out as a villain so that Sasuke would someday kill him to avenge their family. To keep Sasuke safe until then, Itachi threatened to share everything he knew about Konoha with its enemies if the village ever harmed Sasuke. In the meantime, he joined the criminal organization Akatsuki to keep an eye on it and Madara in case they ever conspired against Konoha.[14]
[edit] Personality
Itachi usually has a dispassionate appearance, rarely showing emotion and keeping his composure even when surprised or irritated. When first introduced, Itachi is portrayed as being extremely loyal to Akatsuki, trying to have Kakashi Hatake disposed of for knowing something about the secretive organization. He is also shown to be confident in his abilities, taunting Kakashi for not being as strong as he is. In both instances, Itachi proves to be on good terms with his partner, Kisame Hoshigaki, who immediately does as he asks and worries about Itachi's well-being.[15] He is more considerate to his opponents in Part II, praising Kakashi during their re-encounter for improving his abilities and, when later confronting Naruto Uzumaki, only desiring to speak with him.[16][17] Itachi is, however, consistently hostile towards Sasuke; during their first meeting since the destruction of the Uchiha, Itachi breaks Sasuke's wrist and ridicules him for still being weak.[18] This attitude reaches its peak in the conversation that precedes Itachi's death, where he abandons his passive expression for excitement at the prospect of finally getting to kill Sasuke.[19] This is all explained to be a facade after his death, as his chief concern is Sasuke's safety, the evil persona being used only to cement Sasuke's resolution to kill him.[14]
[edit] Abilities
Within the series, Itachi is renowned for his mastery of all ninja abilities. From his days as a ninja of Konoha, Konoha ninja know by reputation not to underestimate Itachi, his killing of the Uchiha clan only elevating him to the classification of an extremely dangerous criminal. During his appearances he is shown to be very fast with his movements, with such actions as attacking before his opponents have the chance to respond and making his hand seals so fast that even those with a Sharingan cannot follow them.[20] Generally, however, Itachi does not actively participate in battles, remaining in a stationary position where he analyzes an opponent's actions, only then acting in self-defense. In these instances he relies heavily on trapping opponents in illusions to keep them preoccupied, something he can do merely by pointing or looking at them.[21]
As an Uchiha, Itachi possesses a Sharingan, an eye technique that gives the user heightened analytical capabilities. Before he assassinated the Uchiha he killed his best friend to advance his Sharingan to its next level: the Mangekyo Sharingan. When activated, the Mangekyo Sharingan changes the Sharingan's appearance and grants Itachi with abilities derived from Japanese mythology. The first, Tsukuyomi (月読?), traps his opponent in an illusory realm in which Itachi is allowed to torture said opponent for what seems like days in a matter of moments.[22] The second, Amaterasu (天照?), generates black flames at his focal point that will continue to burn until the target is reduced to ash.[23] The final ability, Susanoo (須佐能乎?), creates a massive ethereal warrior that uses the Totsuka-no-Tsurugi to attack for him and the Yata no Kagami to protect him.[24] Despite the effectiveness of the techniques, use of the Mangekyo Sharingan deteriorates Itachi's eyesight to the point of blindness. Only by taking Sasuke's eyes can he restore his vision.[19]

Naruto Uzumaki is a young boy who has the Nine-Tailed Demon Fox sealed within him. Twelve years before the start of the series, the Nine-Tailed Demon Fox attacked the ninja village Konohagakure, slaughtering many people. In response, the leader of Konohagakure and its ninja military – the Fourth Hokage – sacrificed his life to seal the demon inside Naruto when he was a newborn. Konohagakure, however, regarded Naruto as if he were the demon fox itself and mistreated him throughout most of his childhood. A decree made by the Third Hokage, who replaced the Fourth Hokage after his death, forbade anyone mention the attack of the demon fox to anyone else. This included Naruto, who was not aware of the demon inside of him.
Years later, Naruto is tricked by the renegade ninja Mizuki into stealing a forbidden scroll, but he is stopped by his teacher, Iruka Umino. When Iruka almost dies while protecting Naruto from Mizuki, Naruto uses a supernatural ability Jutsu he learned from the scroll that creates multiple clones of himself, Shadow Clone Technique, to defeat Mizuki. This encounter leads Naruto to realize that he is the container of the demon fox.
The main story follows Naruto and his friends' personal growth. Naruto befriends two comrades, Sasuke Uchiha and Sakura Haruno, who are assigned with him to form a three-person team named Team 7 under an experienced sensei named Kakashi Hatake. Like all the ninja teams from every village, Team 7 is charged with completing missions requested by villagers, such as doing chores or being bodyguards. During the course of their missions, Naruto befriends other characters that he meets throughout the series. Team 7 learns new abilities, get to know each other, and experience a coming-of-age journey as Naruto dreams of becoming the Hokage of Konohagakure.
After several missions, Kakashi allows Team 7 to participate into a ninja exam in which they can improve their ranks, and thus, take part in more difficult missions. During the exams, Orochimaru, a criminal at the top of Konohagakure's most wanted list, attacks Konoha and kills the Third Hokage in an act of revenge. This forces one of the three legendary ninja, Jiraiya to search for his former teammate Tsunade, who has been nominated to become the Fifth Hokage. During the search, it is revealed that Orochimaru desires to acquire Sasuke Uchiha due to his powerful genetic heritage. Believing Orochimaru will be able to give him the strength needed to kill his brother Itachi, who destroyed his clan, Sasuke goes to him in search of power. Tsunade sends a group of ninja including Naruto to make Sasuke return to Konoha, but Naruto is unable to defeat him and bring him back to the village. Naruto does not give up on Sasuke, however, and he leaves Konoha to train for two-and-a-half years under Jiraiya's tutelage in order to prepare himself for the next time he encounters Sasuke.
After the training period, a mysterious organization called Akatsuki attempts to capture the nine powerful tailed beasts including the Nine-Tailed Demon Fox sealed inside of Naruto. Several ninjas from Konohagakure, including Team 7, fight against the Akatsuki members and search for their teammate Sasuke. Although they manage to save Gaara the host of the One-Tailed beast, Akatsuki is successful in capturing seven of the creatures. In the meantime, Sasuke betrays Orochimaru and faces Itachi to take revenge. Although Itachi dies in battle, Sasuke is later told by the Akatsuki founder Madara Uchiha that Itachi was ordered by Konohagakure's leadership to destroy his clan. Saddened with this revelation, Sasuke joins forces with Akatsuki to destroy Konohagakure. Meanwhile, as several Akatsuki members are defeated by the Konohagakure ninja, their leader, Pain, invades the village to capture Naruto. However, Naruto defeats Pain's multiple bodies and convinces the real one to leave Akatsuki.
With Pain having left, Madara announces that he wants to obtain the nine tailed beasts in order to perform an illusion powerful enough to control humanity. All of the leaders of the five ninja villages refuse to aid him, and instead, join forces to confront him.