About sasuke:

Sasuke Uchiha is a main character in the anime and manga series Naruto.
Sasuke's given name comes from the legendary ninja Sarutobi Sasuke. His surname, Uchiha, is another way of pronouncing "uchiwa", or a paper fan, which is actually the Uchiha clan symbol. Uchiwa cannot be folded. In contrast, Ōgi, which Temari uses as her weapon, can be folded. Although both uchiwa and ōgi produce wind by fanning, the former is used in more practical/everyday situation such as cooking or commoners cooling themselves down during a hot summer day. The latter is considered to be more formal. Uchiwa can be used to fan flames, making the flame hotter — referring to the fact that the Uchiha is a clan of fire-jutsu users.
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 learns everything easily compared to the less predictable Naruto. This is an odd statement to make, as he is horribly lazy. This is shown with his complete lack of knowledge in every subject that "will not help him avenge his clan."
In Shonen Jump's character popularity polls, Sasuke usually ranked the 3rd or 4th spot for the majority of the series. More recently, however, he has been ranked at 1st.

Sasuke's early childhood:


The second son of a Konoha police captain, Sasuke grew up in the shadow of his older brother, Itachi. Itachi was an acknowledged prodigy who graduated at the top of his Academy class at age 7, mastered the Sharingan by age 8, became a Chunin at age 10, and an ANBU squad leader at the age of 13. The Uchiha clan took great pride and interest in Itachi and viewed him as a genius whose work would further strengthen the bonds between the village and the clan. In particular, Sasuke's father took an active interest in Itachi. Itachi, on the other hand, was rather ambivalent and full of oddly conflicting undercurrents, acknowledging Sasuke by taking interest in his progress as a ninja when even their father did not, but spending little quality time with Sasuke. Even after Sasuke enrolled in the Ninja Academy, he still was unable to escape Itachi's shadow. Despite consistently scoring at the head of every class, Sasuke failed to receive any recognition from his father, who defined Sasuke's success only in terms of his older brother. Itachi acknowledged the rivalry Sasuke felt, telling him, "We are unique siblings. I am the barrier you must overcome, so you and I will continue to exist together."
Itachi's relationship with his father deteriorated further when Itachi was questioned by other members of the Uchiha clan regarding the death and suicide note of his best friend, Shisui. As Itachi's behavior became increasingly bizarre, Sasuke's father, on a whim and partly due to Itachi's growing distance, decided to spend time with Sasuke. He taught him the Great Fireball Technique, a common family jutsu. Sasuke (age 7 at the time) eventually succeeded in performing the jutsu in front of his father after only one week of training, surprising him. At that moment, Sasuke finally received his father's recognition; the Uchiha clan considered the ability to perform fire jutsu as proof that one had become an adult. Sasuke's father told him that he could now proudly wear the clan's emblem on his back. More forebodingly, Sasuke also received a stern warning not to follow in Itachi's footsteps.
Shortly thereafter, Itachi massacred every member of the Uchiha clan, sparing only Sasuke. Itachi said that Sasuke was not even worth killing. In addition, Itachi told him, "You've always wanted to surpass me. That's why I'm going to let you live." Itachi also revealed to Sasuke where the secret meeting place of the Uchiha was hidden and suggested that Sasuke go there to learn what the true history and purpose of the Sharingan is. Sasuke thought he has fainted after this, but he recently remembered that he managed to stand back up, awaken his Sharingan and chase after Itachi. Sasuke managed to knock off Itachi's headband, and Itachi was seen shedding a tear after picking up the headband.

Personality:

During Part I, Sasuke was considered the best Genin of the Rookie Nine, and could have been the strongest. To this end, Sasuke's only desire as a shinobi was to get stronger, and he saw everything from his teammates, to the other villagers as simply being in the way. In fact, during their first bell test with Kakashi, Sasuke's reason for not working with Naruto and Sakura was because he thought they were respectively weak and annoying, and they would get in his way. However when he was proven wrong by Sakura's knowledge, and Naruto's desire to also become stronger he began to value his teammates and even began to risk his life to save them if he needed to, valuing their lives more than his desire to kill Itachi. Masashi Kishimoto, in the voice of Kakashi, remarks that while Sasuke is a genius, he was dull to teach because he learned techniques easily compared to Naruto.
During the Chunin Exams, Orochimaru noticed how Sasuke's desire for revenge seemed to have lessened, and branded him with the Cursed Seal of Heaven to give him a taste of the power he could have if he keeps to his previous path of vengeance. Even when Kakashi sealed the Cursed Seal, Sasuke began to draw more and more power from it in hope to get stronger himself. However even with the Cursed Seal, Sasuke began to envy Naruto, whom he saw as being much weaker than himself, because in their brief encounter, Itachi says that Naruto has a "special power" and that he came back to Konoha to find him, not to Sasuke. Slowly Sasuke saw Naruto surpass him, and in the end, Sasuke decides to defect from Konoha to join Orochimaru to make himself stronger. Sasuke remembers that Itachi told him to be as strong as him, Sasuke had to gain the Mangekyo Sharingan and to do that, he had to kill his best friend. When given the chance to kill Naruto and get the Mangekyo Sharingan, Sasuke simply punched him in the chest, sparing him as to not give Itachi the satisfaction of seeing him follow his path.
In Part II, Sasuke showed he had stayed true to his original personality. When first meeting Sai, he did not care the slightest and was interested more in Orochimaru's presence. When Sai states that he might be able to get along better with Sasuke than he did with Naruto, Sasuke freezes him with a stare, catching Sai in a genjutsu exuding a large amount of killing intent. Sai is amazed that even an emotionless person such as himself was affected by Sasuke's gaze, showing the power of his Sharingan. When Sai comments on how Naruto and Sakura have been searching for him, Sasuke once again regards him with indifference.
It would appear that during his time with Orochimaru, he has come to the conclusion that if he ever wishes to stand a chance against Itachi, he needs to push away all of his past bonds with his friends and make revenge a priority, above even his own life. Because of this, he shows that he no longer cares about Konoha or anyone from the village. In spite of this, he scolds Naruto about risking the lives of an entire squad to save one man, and comments that it could damage his chances of becoming Hokage. He also states that, unlike their last encounter at the waterfall, he has no more reservations about killing Naruto, and attempts to do so. He's also aware of the fact he is intended to be the container for Orochimaru's soul, showing that he doesn't care what happens to himself as long as it results in Itachi's death. This attitude seems to have changed, however, as Sasuke comes to the conclusion that Orochimaru only wants him as a container and attempts to kill him. During his attack, he emphasized to Orochimaru the superiority of the Uchiha clan, demonstrating that he still holds his clan in the highest regard, and that Orochimaru taking his body would be an insult to the clan's reputation.
Unlike Kabuto or any of Orochimaru's subordinates, who address Orochimaru as "Orochimaru-sama" (which shows that they highly respect him), Sasuke simply refers to him as Orochimaru. Sasuke also never called Kakashi "Kakashi-sensei" (teacher) like the others did, something the Japanese would consider as very insulting or rude. Despite his association with the Sound Village, Sasuke does not wear a Sound headband, unlike most other subordinates of Orochimaru. He still wears the fan symbol of the Uchiha clan on his back, albeit much smaller and higher up by his shirt 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.[7]

Abilities:

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, which is most immediately evident through his proficiency with the Uchiha clan's Fire Element Techniques, as well as a number of other weapon-dependent attacks. In addition, both Madara Uchiha and Orochimaru have stated that Sasuke possesses the ability to become much stronger than Itachi. By Part II, he develops some of his potential and becomes a very powerful ninja. As a member of the Uchiha clan, Sasuke possesses the Sharingan, the Clan's Bloodline Limit, which first develops during Itachi's departure from Konoha after the Uchiha Clan Massacre and eventually reaches completion during his battle with Naruto at the end of Part I. However in recent chapters it is revealed that he already developed his One-Tomoed Sharingan, after Itachi killed the clan, where Sasuke, had surpressed some memories of him chasing after Itachi, and then seeing him cry[8]. While his ability with the Sharingan is fairly ordinary during Part I, 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 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 Genjutsu abilities have also increased over the timeskip, allowing him to easily hypnotize opponents. His skill with the Sharingan has grown to the point where he could dispel the Mangekyo Sharingan Genjutsu, Tsukuyomi.
During his battle with Itachi, Itachi kills Orochimaru, removing Sasuke's seal, then dies himself but passes his Mangekyo Sharingan to Sasuke through a poke on the forehead. Itachi did it in an effort to help him fight against Madara, setting to activate when it catches sight of Madara's Sharingan. Later, when he realizes that Itachi was good after all, and did all he could to protect Sasuke and help him grow, Sasuke awakens his own Mangekyo Sharingan[9].
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 (ハヤブサ落とし, 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 (獅子連弾, Shishi Rendan; English TV "Lion's Barrage", Ultimate 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. Sakura mentions after their first encounter in Part II that his growth rate wasn't normal, even suggesting that Sasuke has been taking special drugs.
Orochimaru's influence has also added a number of abilities to Sasuke's arsenal, as first seen with his Cursed Seal of Heaven. After recovering from the initial application of the seal, Sasuke finds himself endowed with increased power, as well as a darker personality when the Cursed Seal is active. When he battled Naruto, he forced the Cursed Seal to Level 2, which had power comparable to One-Tailed Naruto. The Second Level of the Cursed Seal turns Sasuke's skin dark grey, grows his hair longer without losing its style, a dark star-shaped mark on the bridge of his nose and hand shaped wings on his back. In Part II, Sasuke gains complete control over the Cursed Seal, and can even perform partial activations of it. As with Jiraiya passing toads to Naruto, Orochimaru gave Sasuke the Snake Contract to use the Summoning Technique to snakes such as Manda. Sasuke can also use Hidden Shadow Snake Hands to summon snakes from his hands to attack opponents or wrap around him as a shield. After absorbing Orochimaru, Sasuke is able to use Orochimaru's Oral Rebirth Technique to shed his skin, repairing damage to his body. After Itachi seals Orochimaru away, Sasuke's Cursed Seal dissapears.
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. 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 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 Kusanagi, creating a destructive blade. 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. He has also shown the ability to send the chidori through the ground, creating an electric current beneath his opponent's feet. His most powerful technique is the Kirin, a technique which requires real lightning as opposed to his chakra. If there are no clouds available, Sasuke can use Fire Release: Great Dragon Fire Technique (火遁・豪龍火, Katon: Gouryūka no Jutsu) to make the right storm conditions and Sasuke simply has to use his chakra to draw the lightning towards his foe.