Sasuke is one of the most important characters in Naruto. About half of Part 1 and most of Naruto Shippuden is dedicated to Naruto and the rest of Team 7 trying to bring Sasuke back to the Leaf Village. However, his goal to get revenge on Itachi for massacring the Uchiha Clan blinded him from making the right decisions.
Despite having vastly different personalities, Sasuke and his brother are quite similar in some respects. However, he never really understood the reasons for any of his brother's actions until after Itachi died.
So, here are five ways Sasuke was similar to Itachi in Naruto and the five times he was his polar opposite.
Naruto: 5 ways Sasuke was a lot like Itachi
1) He deserted the Leaf Village
After killing almost all of the Uchiha Clan, Itachi left the Village Hidden in the Leaves. He did this to make sure his younger brother came to hunt him down, and it worked.
Sasuke did hunt down Itachi. He even defected from Konoha, just like his older brother, in order to get much stronger and kill Itachi. This decision was terrible for Sasuke at the time, but it allowed him to learn the truth behind the Uchiha Massacre and was the catalyst for his amazing character development.
2) He joined the Akatsuki
After Itachi left Konoha, he encountered the Akatsuki. To make sure his plan went as smoothly as possible, he joined the group and helped them secure the nine Jinchurikis. While being a member, Itachi got many opportunities to further stoke the fire burning in Sasuke's heart, and made Sasuke want to kill him more than ever.
Sasuke joined the Akatsuki after his final fight with Itachi and Itachi's death. He heard the truth about the Uchiha Massacre from Itachi and joined the Akatsuki in an effort to avenge his older brother by destroying Konoha.
3) He defeated Orochimaru
Orochimaru joined the Akatsuki in order to get closer to Itachi. He wanted to steal his body. So, one day he caught Itachi alone and cornered him. However, when he got his snakes around Itachi, Orochimaru realized he was completely outclassed. Just one glance from Itachi's Sharingan was enough to incapacitate the Snake Sannin.
His younger brother defeated Orochimaru as well, albeit not as swiftly or easily. Orochimaru attempted to take over Sasuke's body by using the Living Corpse Reincarnation Jutsu, but Sasuke was able to stop him from completing the Jutsu. The pair then engaged in a duel and the Uchiha succeeded in killing one of Orochimaru's host bodies.
4) He is a Fire Style master
Itachi has always been a prodigy, but since he was an Uchiha, he excelled in Fire Style Jutsu. When he was a kid, his Fireball Jutsu was comparable to those of the strongest Uchiha adults at the time.
Although Sasuke was never a prodigy like Itachi, his hard work and power ups got him to and beyond Itachi's level. By the time he became proficient in using the Curse Mark, he was able to counter and overpower Itachi's Fireball Jutsu with his own.
They also both share the same strongest Fire Style Jutsu, Amaterasu.
5) He awakened the Mangekyo Sharingan
Both Sasuke and Itachi awakened their Mangekyo Sharingan by watching people they care about die. Itachi awakened his when he watched his best friend, Shisui Uchiha, fall off a cliff and into a rushing river. The younger awakened his Mangekyo Sharingan after witnessing Itachi's death.
5 times Sasuke was Itachi's polar opposite
1) He unlocked the Rinnegan
After getting a portion of Hagoromo's Six Paths chakra, Sasuke awakened the Six Paths Rinnegan. This dojutsu gave him a massive power boost and made him one of the strongest characters in the series.
Itachi never awakened the Rinnegan. He stopped at the Mangekyo Sharingan, but he was still incredibly powerful despite this.
2) He never joined the Anbu
After becoming a chunin at a very young age, Itachi quickly joined the Anbu. He further honed his skills as a shinobi and became one of the strongest individuals in the Hidden Leaf.
Although he became much stronger than Itachi and anybody in the Anbu, Sasuke was never promoted to the rank of chunin, nor did he join the Anbu.
3) He got the Cursed Seal of Heaven
During the first chunin exams in Naruto, Sasuke and Sakura encountered Orochimaru in the forest. Before either of the genin could react, Orochimaru had bitten into the young Uchiha's neck and implanted a Curse Mark on him. This would serve as Sasuke's main power-up for the rest of Part 1 and much of Naruto Shippuden.
4) He started a family
Though Sasuke was never focused on becoming a husband and father during Naruto and Naruto Shippuden, he is happy to be one now. He married Sakura and had a daughter named Sarada. He was able to start a family, but Itachi died before being able to do this.
However, during the Uchiha Massacre, Itachi technically started a family with Izumi Uchiha. He used the Tsukuyomi to let her experience an entire life where he marries her and they live a long, happy life with their kids. Since it was only a genjutsu, it never actually happened.
5) He fights Otsutsuki
Itachi succumbed to his disease way before Kaguya Otsutsuki was introduced in the anime. Unlike his younger brother, Itachi never had to fight against Kaguya in order to save the world. But he probably wouldn't have made it that far anyway since the Otsutsuki Clan is just too much for Itachi to handle.
Note: The article reflects the writer's own views.