Board Thread:Naruto Discussions/@comment-31278419-20170331010234/@comment-734582-20170505170450

Rachin123 wrote: Even after defeating Itachi, did he go back to the village? No he didn't. Considering that Itachi forced Sasuke to hate him and mentally abused him, it's no surprise he didn't take Obito's revelations well. In this moment Sasuke was vulnerable to manipulation and Obito played him like a fiddle. Sasuke straight up reveals to Itachi that he had survivor's guilt, his actions toward Sakura reveal proper insanity.

The trauma forced upon him by Itachi didn't stop when he killed Itachi. It straight up caused his period of insanity because the way Itachi programmed him, he simply couldn't parse the information that Itachi had the right intentions. He was programmed to hate his brother, in order to restore the honor of the Uchiha clan. But if his brother did it to save the Uchiha clan, it means his mission wasn't finished, since he still had to clear the Uchiha name. This extended it to the Village Elders. But the village situation caused the Uchiha downfall, forcing the elders to enact the Massacre, which in turn makes the village guilty for the Uchiha downfall and thus they have to be killed to restore the Uchiha Name.

This is what Sasuke's mind couldn't handle. He had lived the majority of his aware life for the purpose of one single mission, and then that mission was a lie. Itachi's extremely fucked up mental machinations are the cause of Sasuke's evilness. Had he been caught after Itachi's death, he probably would still have had a major backlash but he'd probably reverted eventually to his true self. As we know, Obito's machinations only made things worse.

Because even in the end, Sasuke's final solution of a Dark Hokage, a person who machinates things from the shadows and takes on the hatred of the world, is exactly what he saw in Itachi. The genjutsu manipulation didn't end until he was dying with part of his arm missing.