The new Akatsuki Team member

Madara collected Sasuke, tended to his wounds, and tried to befriend him when he awoke. When he removed his mask while doing the latter, Sasuke reflexively used Amaterasu on him. After quelling the flames, Madara explained that the Amaterasu had been inserted in Sasuke by Itachi, intended to protect him from Madara and whatever he might say. Sasuke was perplexed, so Madara went onto detail the history of the Uchiha clan, and the truth behind Itachi's life. Towards the end of his story, he explained that Itachi had been dying of disease, but had kept himself going with medicine so that he could die by Sasuke's hands, stating that if Itachi had battled with all his strength they wouldn't be having that conversation. He also stated that Itachi had pushed Sasuke to his limits during their battle to draw out Orochimaru, so that he could remove the latter's influence from his beloved little brother.
Sasuke was unwilling to believe the story. Madara persisted, saying that Itachi had entrusted the Uchiha name to Sasuke, hoping he would rebuild the clan on a new foundation of honor and nobility. For the sake of Konoha, and for Sasuke, he had been willing to die as a traitor and criminal. He had traded honor for disgrace and Sasuke's love for his hatred, and even then he had died smiling. Finally accepting the truth, Sasuke was crushed to find that the brother he had hated had actually been looking out for him all along. Upon realizing the truth, he awakened his Mangekyō Sharingan and resolved to take vengeance against Konoha for the massacre of his clan and the fate they placed on his brother, regardless of Itachi's attachment to the village. He also agreed to start working with Madara and, as a result, is classified as an international criminal, something Itachi had tried to prevent by sacrificing everything he had, but even that had not been enough to deter Sasuke.
Sasuke initially refused to transplant Itachi's eyes into his own sockets, due to the two of them having completely different visions of the future. However, after his reckless overuse of his own Mangekyō Sharingan from battling Killer Bee, A, Danzō Shimura and Team 7, Sasuke's eyesight had greatly deteriorated. As such, he decided to abandon his refusal, and take Itachi's eyes to use them to destroy Naruto at full power. The transplant was then commenced by Madara, and Sasuke felt Itachi's power flowing through him