The Light and Dark of the Mangekyō Sharingan

Synopsis
Sasuke finds Itachi's claim of Madara Uchiha being a co-conspirator of the Uchiha Clan Downfall to be a farce, since Madara was the co-founder of Konohagakure and thus should be long dead. Itachi reminds Sasuke that one's reality is merely another's fantasy and that the truth is that Madara is still alive, whether he would like to believe it or not. As Sasuke has his sword impaled through Itachi's back, he tells Itachi that his Sharingan has matured to a point where Itachi's genjutsu won't work on him; Sasuke then turns around and fires a Chidori Sharp Spear at the real Itachi, who is sitting behind him, missing Itachi's face by inches. The brothers are unaware that their bout is being witnessed by Zetsu, who wonders why they haven't begun their clash already.

Itachi tells Sasuke that he would like to take the time to share a little history regarding the Uchiha clan and pulls Sasuke into a genjutsu, where Sasuke sees Madara and his younger brother Izuna sparring. Itachi explains that the two brothers always fought one another to push each to their limits and eventually killed their own comrades to awaken the Mangekyō Sharingan. With the Mangekyō granting him visual prowess, Madara became the head of the clan and waged war against numerous villages; however, the Mangekyō had a price for those who used its abilities, and Madara was rendered blind. Desperate to regain his vision once more, Madara stole his brother Izuna's eyes and fused them with his own, creating an Eternal Mangekyō Sharingan that heightens the user's visual prowess and does not cause them to lose their vision.

Eventually, Madara formed an alliance with Hashirama Senju of the Senju clan, who would become the First Hokage, and fought for leadership at the Valley of the End. In a bid to gain vengeance, Itachi reveals that it was Madara who unleashed the Nine-Tailed Fox on Konoha 16 years ago, as he was able to control the tailed beast with his Eternal Mangekyō. Itachi tells Sasuke that since the Eternal Mangekyō can only be activated by taking the Sharingan eyes of a close family member, ideally a sibling, he plans to take Sasuke's eyes and reach a status higher than Madara himself ever obtained.

Realising that his life's goal is finally in front of him, Sasuke removes his bandages as he launches a volley of shuriken at Itachi, who fires his own back. Sasuke rushes towards Itachi with his sword, who blocks it. As they remain locked in each other's grip, Itachi's shadow clone comes from above, throwing kunai towards Sasuke. Forcing a snake to burst out of his cursed seal, Sasuke uses the snake to shield himself and leap backwards. Using the Unsealing Technique, Sasuke summons a fūma shuriken and hurls it at Itachi, who blocks it with a kunai. However, Sasuke managed to imbue the fūma shuriken with his Lightning Release, running his Chidori through it; the process destroys the Itachi shadow clone.

Using his Mangekyō, Itachi arrives before Sasuke and kicks him into a wall, trapping his arms and feet. He asks Sasuke to forgive him as he seemingly removes Sasuke's Sharingan eyes.

Trivia

 * In the previous episode, Itachi tells Sasuke that if he had awoken his Mangekyō Sharingan, he would have been the third person in the clan's history to do so. However, in this episode, Itachi tells Sasuke that both Madara and his younger brother Izuna had awoken the Mangekyō Sharingan in their youth, thus making Itachi the third person.