Naruto- Sasuke's character development

As a child Sasuke was kind and loving towards his family (especially Itachi) and respectful to his clan and teachers. He admired his older brother and wanted to be like him and he also desired his father’s approval and recognition.

He began to change when his entire family and clan were killed by Itachi, turning him into a cold and arrogant avenger. Though I believe he felt hurt and lonely inside, he rejected others in favor of solitude. His arrogance made him ignore those he considered inferior, thinking they would be a hindrance in achieving his goal.

When he became a member of team Kakashi, Sasuke grew attached to them and think of them as a family. He began losing some of his cold demeanor and he even put his life in danger a few times, for his team (especially for Naruto). As he later admitted to Sakura, he almost thought that he must forget about his revenge and instead focus on Team 7. This happened especially thanks to Naruto. When Sasuke’s family and friends were alive the two boys were rivals, because Sasuke’s skills were better and he was more popular with girls than Naruto.

After Sasuke lost his family and clan a bond was created between him and Naruto, because they shared the same pain of being lonely and viewed as outcasts by the other villagers. Even if Naruto had grown up alone and Sasuke had a family but than lost it, they both knew sorrow and suffering that made them stronger. A bond of friendly rivalry, because both of them were too proud to openly admit that they actually wanted to be friends. Naruto admits later that this bond was the first he made and that he sees Sasuke as a brother; that’s why he’s so determined to chase the Uchiha boy to the end of the world in order to bring him back to Konoha. This bond is precious to both of them, but especially to Naruto. That is why the moment when Sasuke finally acknowledges him is so touching and important to the blonde boy.

However, when Orochimaru branded Sasuke with the Cursed Seal he pushed the Uchiha boy back on the path of vengeance and power. Though Sasuke still struggles with choosing between revenge and those he loves, in the end he becomes more and more obsessed with power and gradually loses his humanity.

According to Kakashi Hatake, Sasuke has both a superiority and an inferiority complex, as he is unwilling to acknowledge when someone is stronger than him, but obsesses when he believes that they are. Sasuke was dismissive of his rivalry towards Naruto when he was sure he was the better, only to obsess over Naruto’s fast growth after the latter defeated Gaara. He’s so concerned with this that he doesn’t notice his own growth and is under the impression that he is weaker than Naruto. The Uzumaki boy, who still admires Sasuke a lot and is happy to finally be acknowledged by him, doesn’t understand the sudden change in Sasuke and is determined to get some answers and prevent Sasuke from walking the path of revenge, even against the Uchiha boy’s will.

At first Sasuke didn’t want to kill Naruto because he didn’t want to follow the path indicated by Itachi, but instead wanted to gain power in his own way. After training with Orochimaru and severing the ties he believed bound him, Sasuke was apparently willing to kill Naruto just to prove a point at how much he had changed. He became increasingly confident in his strength and retained the habit of underestimating his opponents, though he acknowledged his mistakes and was not above making bonds with those around him (like he did with the members of his own new team, Taka).

According to Obito Uchiha, Sasuke alone was shouldering the entire hatred of the Uchiha clan. After learning the truth about Itachi’s actions Sasuke vowed revenge against the entire Konoha village, even if that was against Itachi’s wishes and would bring disaster for the entire world.

In the end, Sasuke is just a confused “child” looking for recognition and power to fill the void left by the loneliness and hurt he felt inside. He was jealous of Naruto because he could turn loneliness into strength and created bonds with people, that made him stronger, while Sasuke rejected those bonds believing they are a weakness and choosing solitude instead. Sasuke himself realizes in the end that he always followed behind Naruto just as he did with his older brother Itachi.

Concerning Sakura, Sasuke does show genuine affection for her in the end, as well as remorse for what he did to her and to the entire shinobi world.