Truth

is episode 141 of the Naruto: Shippūden anime.

Synopsis
Tobi continues by informing Sasuke that Itachi was a double-agent who was assigned to leak intel on the Uchiha back to the village. He then contacted Tobi to help him undertake his mission of exterminating the Uchiha clan. They pulled off their mission, except Itachi just couldn't kill Sasuke. Some time later, Sasuke reminisces on Itachi's final words to him, before breaking down into tears. He then changes his team's name to Taka and declares, with his new Mangekyō Sharingan, that their goal is to destroy Konoha.