Because the Naruto timeline spans from Naruto's childhood into his adulthood, many characters had time to develop in both maturity and ninja skill. Naruto himself went from being an underdog and failure to one of the most respected ninjas of all time.
Likewise, Naruto's closest friend and rival, Sasuke also underwent some major changes throughout the course of the story. In fact, Sasuke's glow up was quite possibly the most drastic amongst all the characters in the series due to his complexities and struggles with the darkness inside him. While he might have maintained his edgy vibe, it's no secret that Sasuke is a changed man from who he was at the very beginning.
10 Fully Awakened His Sharingan
As a member of the elite Uchiha Clan, Sasuke has a unique kekkei genkai technique, the Sharingan, that is exclusive to his bloodline. The Sharingan is a special kind of eye that not only enhances visual perception but also allows the user to instantly copy another ninja's technique with ease.
Prior to when the Naruto series began, Sasuke had unknowingly awakened his Sharingan during his clan's massacre but couldn't use it again afterward. It wasn't until his battle with Haku that Sasuke gained full awareness and control over the power of his eyes. His Mangekyo Sharingan appeared later in the series after witnessing the death of his brother.
9 Wields A Sword
In the Naruto ninja world, the first ninja tools we generally think of are kunai knives and shuriken. For the entirety of Part One, Sasuke had stuck with these weapons in addition to his Sharingan, taijutsu, and ninjutsu.
However, after fleeing the village to train with Orochimaru, one of the most notable changes to Sasuke was his choice of weapon. Rather than kunai knives or shuriken, he opted to wield a sword. With his signature sword, the "Sword of Kusanagi," Sasuke could combine his lightning techniques with his sword for an even greater attack.
8 Learned The Truth About Itachi
Ever since Itachi murdered the Uchiha Clan, Sasuke was under the assumption that his older brother was an evil force whom he needed to kill. He had no way of knowing that Itachi actually had a legitimate reason for getting blood on his hands. And the truth didn't come out until after Itachi's death.
After his final battle with his brother, Sasuke was finally told the truth about Itachi by Tobi. As it turned out, Itachi had been ordered by the village to kill his clan in order to prevent a coup. Sasuke's life was only spared because Itachi couldn't bear to kill his baby brother.
7 Acquired The Rinnegan
Without any special eye, Sasuke was already a talented ninja. After awakening his Sharingan, he grew stronger. After upgrading to the Mangekyo Sharingan, he was near unstoppable. As if the Uchiha blood, Sharingan, and Mangekyo Sharingan were not already enough, Sasuke was also blessed with the even rarer Rinnegan.
Similar to the Sharingan, the Rinnegan was another special kind of eye and kekkei genkai that greatly enhanced the abilities of its user. When the Sage of Six Paths gave Sasuke access to the Rinnegan, the Uchiha easily became one of the strongest ninjas out there.
6 Stopped Trying To Kill The Ones Closest To Him
In his first self-introduction, Sasuke made it very clear that his ultimate goal was to kill his own brother despite how close they had been prior to their clan's murder. After Itachi mentioned that the powerful Mangekyo Sharingan could only be awakened by killing the person closest to them, Sasuke had to be willing to kill just about anyone.
When he abandoned the village along with his friendships, Sasuke was committing to killing not only his brother but also Naruto and Sakura. But despite his multiple attempts to kill his friends, Sasuke eventually learned that rather than revenge, he could be empowered by friendship.
5 Became A Hero
When Sasuke's only initial goal was to kill his brother, it always seemed as though he was destined to let the darkness consume him. For a time, he was the biggest threat and enemy of the village. However, his path completely changed course in the midst of the Fourth Shinobi War.
As soon as Sasuke got the closure he needed from his brother to let go of the past, he decided to save the ninja world rather than destroy it. Together with Naruto, Sasuke defeated Kaguya, freed the world of the Infinite Tsukuyomi, and ended the war.
4 Lost An Arm
Sasuke and Naruto might have been rivals since day one, but the fullest extent of their heated rivalry was not reached until after the conclusion of the Fourth Shinobi War. Throughout the series, they had constantly fought and trained to outshine one another in preparation for that one last rival battle.
Ultimately, the battle ended in a draw because they had both lost an arm each. While Naruto eventually got a prosthetic arm to replace his real one, Sasuke opted to continue on with his ninja life with a single arm.
3 Has A Family
Like Naruto, Sasuke was an orphan who didn't have a family around for love or support. But unlike his rival who was raised without a family from the start, Sasuke once knew what it was like to feel the love of a family until it was stripped away from him.
Many years later after Sasuke made amends with the village post-war, he also had some time to reconnect with the girl who never stopped loving him- Sakura. In the end, they got married and had a child, Sarada, to begin rebuilding the Uchiha Clan.
2 No Longer Driven By Revenge
From the very beginning, Sasuke's heart was full of hate and revenge. With the sole intent to avenge his fallen clan, Sasuke first set his sights on killing Itachi. Once Itachi died and it was revealed that he was only following orders from Konohagakure, Sasuke then sought to avenge his clan and his brother by destroying the village.
However, after learning to let go of tragedies of the past, Sasuke was finally able to move forward toward a brighter future. Rather than be guided by hatred and revenge, he instead became motivated by his will to protect those he cares about.
1 Tolerates Sakura
From beginning to end, Sakura never stopped loving Sasuke, but the same cannot be said about his feelings toward her. While Sakura had the biggest crush on him, Sasuke often could not stand her and her antics. It even got to the point where Sasuke was ready and willing to kill her.
The big shift in Sasuke's feelings for Sakura came when he realized she still believed and saw the good in him, even after he tried to kill her and the rest of the village. Sasuke not only apologized to her for all the pain he put her through but also gave her an affectionate tap on the forehead.