The early years of Sasuke's childhood were spent living in the shadow of his older brother, Itachi Uchiha, who had proven time and again that he was a genius in the ninja arts. Because of Itachi's successes, most of the members of the Uchiha clan looked to Itachi as the clan's future, the biggest proponent of this idea being Sasuke's father, Fugaku Uchiha. Due to this focusing on Itachi, Sasuke did what he could to prove himself to his family, though no amount of training could help him in surpassing the milestones set in place by his brother. Itachi, aware of Sasuke's struggle for recognition, tried to shift some of their father's attention to Sasuke, even offering to train Sasuke in various fields of ninja abilities. Although Itachi succeeded in getting Fugaku to spend more time with Sasuke, much of that time was still dedicated to Itachi, and all the while Itachi never lived up to his promises of training Sasuke.
As time went by, Itachi's standing in the clan began to falter as his trustworthiness was constantly called into question. At this time, Itachi also began to create a more competitive relationship with Sasuke, challenging Sasuke to surpass him. Because of Itachi's changing personality, Fugaku began to take a more active interest in Sasuke's development, teaching him the Great Fireball Technique in less time than Itachi had taken to learn it, which also gave Sasuke proper membership into the clan. Most prominently, Fugaku encouraged Sasuke to not follow in Itachi's footsteps, the former prodigy of the clan having lost his father's confidence.
Soon after receiving the attention from his father that he had so yearned for, Sasuke returned home late one evening to his horror to find all the members of his clan dead. After finding Itachi standing over the bodies of their parents, indicating he was the one responsible for the clans' murders, Itachi informed Sasuke that he wasn't worth killing. As he left, Itachi repeated his encouragement to Sasuke to hate, to hold grudges, and to train his evil to become strong enough one day to surpass him, and disappeared into the night. From that day forth, Sasuke lived as an orphan, longing for the parents that had been taken from him and allowing his brother's words to fester. Soon after the clan's annihilation, Sasuke's only goal in life became to gain power through any means necessary in order to kill Itachi and avenge the clan.
PersonalityAt the start of the series, Sasuke's desire to get stronger is the dominating factor in his interactions with others and takes precedence over all else. As such he is initially unconcerned with the concepts of socializing, be it with his teammates or the many girls in his age group vying for his affection. Likewise, Sasuke is not interested in working with Naruto nor Sakura for the good of the mission, believing himself to be much more talented and that working with them will only make him weaker. Soon after the three set out on missions together, however, Sasuke begins to discover that these perceptions are inaccurate; Sakura is a valuable source of information, and Naruto is an effective ally and incentive to get stronger. As a result of these revelations, Sasuke begins to value his teammates more than he did during their first meeting. While he tries to deny this, his willingness to risk his life to help them even if it could mean never getting a chance to kill Itachi slowly begins to manifest, although this is partly influenced by Sasuke's belief that if he cannot fight in [this] battle, he will never be strong enough to face Itachi. In Shonen Jump's June 2006 edition, Masashi Kishimoto (in Kakashi's voice) remarks that while Sasuke is a genius, he is a little dull to teach because he can learn techniques easily compared to the less predictable Naruto.
During the second phase of the Chunin Exams, Orochimaru notices this change in Sasuke's ideals, witnessing first hand of Sasuke valuing of his teammates' safety over his own. Having need for Sasuke's craving for revenge, Orochimaru brands Sasuke with the Cursed Seal of Heaven to give him a taste of the power he can have and steer him back towards the more "favorable" path of vengeance. Although Kakashi does what he can to weaken the cursed seal, discourage its usage, and give Sasuke other means of getting stronger, Sasuke comes to realize the potential the seal allows him. To test his newfound power, Sasuke begins to seek out strong opponents that he can fight, believing each victory he obtains to be an indicator of his growth. As time goes by, however, Sasuke becomes dissatisfied with the progress he is making in getting stronger, largely a result of his quick defeat by Itachi during their brief encounter. All the while, Naruto, someone he finds to be of lesser skill, continues to surpass him in ability, creating a sense of envy within Sasuke.
Sasuke in Part II
Ultimately, Sasuke decides to abandon Konoha in order to seek out Orochimaru and gain power. Naruto, sent to stop Sasuke from escaping the country, eventually catches up with him and pleads for him to return. Sasuke, believing Naruto to be his closest friend, decides instead to use the last bit of advice Itachi ever gave him: in order to gain the Mangekyo Sharingan, the highest power of the Uchiha clan, one's best friend must be killed. No longer valuing his teammates over his own self-betterment, Sasuke tries to kill Naruto and meets him in battle. Naruto, unwilling to let Sasuke go, fights with equal earnest, now willing to break Sasuke's body to bring him home. As the battle concludes, Sasuke attacks Naruto with his Chidori while Naruto uses his Rasengan. Rather than connect with the attack, Naruto scratches Sasuke's headband (in reference to Sasuke's claim that he couldn't scratch his forehead). As Naruto lies unconscious, Sasuke considers killing him, though upon realizing that that is what Itachi would want, decides to spare Naruto to find power in his own way. He goes to Orochimaru, ready to do whatever is necessary to gain the power he desires.
In Part II, Sasuke sees little change from his personality and mindset at the end of Part I, still craving power above all else. His lust for strength is such that, during his reunion with Naruto and Sakura, he claims to be willing to give his body to Orochimaru if it means killing Itachi. Sasuke has at least changed to a point that he no longer cares for his former teammates' well-beings, being more than willing to kill them since neither is of any use to him. His relationship with Orochimaru shows a similar lack of loyalty, as during their time together he applies no honorifics to Orochimaru's name, is somewhat rude to him, and does not express his allegiance with Otogakure by wearing a Sound headband. Of the loyalties Sasuke has, the only one he displays is that of the Uchiha clan, the symbol of which he wears on his back collar. Despite this lack of allegiances to those close to him, Sasuke seems to be unable to bring himself to needlessly harm those he has never met before, and makes it a point to prevent their deaths when possible.
AbilitiesWhile not on the same level as Itachi in terms of talent, Sasuke is established as a natural genius at the series' start, excelling at all that he does and finding little difficulty in more challenging tasks. This is most immediately evident through his proficiency with the Uchiha clan's fire-based techniques, as well as a number of other weapon-dependent attacks. Of the abilities the Uchiha bloodline has allowed him, Sasuke has found most frequent use in the Sharingan, which first develops during Team 7's mission in the Land of Waves and eventually reaches completion during his battle with Naruto at the end of Part I. While his ability with the Sharingan is fairly ordinary during the first half of the series, Sasuke is able to develop a number of more novel uses for it in Part II. During his encounter with Naruto, Sasuke is able to use his Sharingan to enter Naruto's subconscious where he proceeds to suppress the demon fox residing within Naruto. In this instance, the demon fox compares Sasuke's eyes and chakra to that of Madara Uchiha, which it claims is even more sinister than its own. When Orochimaru later tries to take over his body, Sasuke is able to use his Sharingan to fight the process and turn it against Orochimaru. His Sharingan-based genjutsu abilities have also increased over the timeskip, allowing him to easily hypnotize opponents.
Sasuke is able to put the Sharingan to good use in Part I after his brief encounter with Rock Lee. Although their fight is ended soon after its start and Sasuke is unable to see much of Lee's arsenal, what he is able to copy with his Sharingan is utilized for the duration of the Chunin Exams. His newfound taijutsu abilities are first seen in the form of Peregrine Falcon Drop (Hayabusa Otoshi?), which consists of wrapping himself around an airborne opponent to ensure they are unable to save themselves upon impact with the ground. A derivative of this jutsu is seen again as the Lion Combo (Shishi Rendan?, English TV "Lion's Barrage", Ultamate Ninja "Barrage of Lions"), and after kicking an opponent into the air Sasuke delivers a series of blows to them, eventually culminating in a debilitating kick to the chest.
Sasuke in cursed seal level 2 form
Orochimaru's influence has also added a number of abilities to Sasuke's arsenal, as first seen with his cursed seal. After recovering from the initial application of the seal, Sasuke finds himself endowed with increased speed and strength, as well as less merciful tendencies when the seal is active. In addition, when his chakra reserves are low, Sasuke can use the seal to momentarily give him a boost of chakra. Wanting more of this power, Sasuke abandons Konoha to seek out Orochimaru and forcefully advances his cursed seal to level 2. While in the level 2 form, Sasuke is able to compete with a demon fox-fueled Naruto, and is even given a brief ability to fly when using the wings that grow from his back. In Part II, Sasuke is even able to advance only parts of his body to their second level state, and the curse seal itself becomes less tiring for him to use. In addition to the cursed seal, he gains the snake summoning contract, which is located on his left arm. With it, Sasuke can summon giant snakes to use as shields and to aid him in battle or call forth smaller snakes from his sleeves to immobilize targets. After absorbing Orochimaru, Sasuke is able to heal at a faster rate, an attribute allowed to him by one of the modifications made to Orochimaru's body.
To encourage Sasuke not to use the cursed seal, Kakashi teaches him how to use the Chidori, made more effective when combined with his Sharingan and the speed he has copied from Rock Lee. With this combination Sasuke can punch through the strongest obstacles with relative ease, as well as severely damage any opponent. In Part I Sasuke is limited to using the attack only twice a day, with a third usage after the initial activation of his cursed seal. Once drawing upon more of the cursed seal's power however, Sasuke is able to use the ability much more frequently. Over the timeskip, Sasuke puts great deals of development into the Chidori's ability to manipulate lightning-based chakra. When first seen in Part II he is able to use Chidori Current (千鳥流し, Chidori Nagashi?, lit. One Thousand Birds Current) to emit electricity from all over his body as a shield that stuns those it comes into contact with. If need be, Sasuke can channel this force into his new chokuto, increasing the damage the blade does to opponents. He can even concentrate this chakra into highly condensed needle-like forms, which he can throw in volleys with pinpoint accuracy. Sasuke has also taken to using form manipulation on the Chidori itself to create an extendable blade form, although he is only able to extend it to 5 meters in length. This blade is also capable of splitting into multiple additional blades upon contact with an enemy, drastically increasing the number of wounds it can inflict.
Plot overviewSasuke and his quest to kill Itachi are recurring themes in the overall plot, and as such much of the story is built upon and shaped by his actions that will make this task easier. After first meeting Orochimaru, Sasuke attempts to continue to get stronger while in Konoha, though he believes that he is slow in accomplishing this task in comparison to his peers. When Itachi arrives in Konoha to kidnap Naruto, Sasuke tries to use what he has learned to kill his brother, though Itachi is able to defeat him with little effort and taunts his inability to get stronger. This, coupled with Naruto's rapid increase in strength (further enhanced by his learning the Rasengan, a jutsu stronger than the Chidori), convinces Sasuke to abandon Konoha and seek out Orochimaru as a way to get stronger. While Naruto, Shikamaru, Kiba, Neji, and Choji mobilize to stop Sasuke, he is still able to escape after narrowly defeating Naruto. Because of this, many of the people he leaves behind in Konoha resolve to bring him back, creating a number of future attempts to accomplish this task.
In Part II, one such effort proves successful in at least finding Sasuke, though Sasuke's rapid increase in strength allows him to quickly defeat Naruto, Sakura, and the newer members of Team 7. While he attempts to kill his former comrades, Sasuke is persuaded to spare them in case they can defeat more members of Akatsuki, an organization which Itachi belongs to, and therefore make him easier to kill. Soon afterwards Sasuke turns against Orochimaru, feeling that he can learn nothing else from him and that Orochimaru is unworthy of having his body. Although Orochimaru attempts to take his body by force, Sasuke is able to turn the process against him, later reporting to have simply retained control of his body. With Orochimaru gone, Sasuke recruits Suigetsu Hozuki, Karin, and Jugo, former subordinates and experimental subjects of Orochimaru, to help him in finding and ultimately killing Itachi. Naming their group "Snake", they set out to find Itachi.
Sasuke eventually finds Itachi, and Sasuke displays how much stronger he has gotten. Itachi agrees to have their final battle elsewhere. Sasuke takes Snake with him to the meeting place, though leaves them behind once he reaches his destination. Sasuke and Itachi meet again, and Sasuke prepares to kill his brother at long last.