Perhaps sasuke changed his mind and no longer wants to destroy all of konoha for his families death, but just the elders that issued the order to kill his family. He kills them but can no longer live in the world feeling as though he has nothing left to live for. He challenges Naruto, is long time rival abd best friend feeling he is the only one fit to kill him, threatening to destroy the village and maybe even injures someone close to him to egg him on like sakura or ten ten(shes so expendable), they have an all out brawl where naruto barely wins and as sasuke is about to drop dead he smiles and touchs naruto on the head the same way itachi did to him, and with that one hit, like they have been saying the entire series, these 2 shinobi masters know exactly what the other is thinking. Sasuke dies with no regrets and Naruto knows it is finally over, and goes back into training to become the next hokage.
