Battle of Unraikyo (雲雷峡の闘い, Unraikyō no Tatakai) is episode 142 of the Naruto: Shippūden anime.
The Konoha teams decide to head back home as Sasuke remembers that Itachi cried after the massacre. He then states that he cannot rebuild the Uchiha clan in the same way that Itachi had envisioned. Tobi, happy that he can use Sasuke for himself, assigns Taka the task of capturing the Eight-Tails while Akatsuki hunts the last two Jinchūriki. Taka track down the host, Killer B, to the Land of Lightning and engage him in battle. B manages to overpower Jūgo and Suigetsu before Sasuke steps up to fight him one-on-one to prove his Mangekyō Sharingan.