"Two Fates" (宿命のふたり, Shukumei no Futari) is episode 215 of the Naruto: Shippūden anime.
After Sasuke attempts to stab Sakura, Naruto arrives just in time to save her, taking a small scratch on the cheek in the process. Naruto informs Sasuke he has learned the truth about Itachi from Tobi, and wants to save him from his path of revenge but Sasuke cynically rejects Naruto's offer by announcing that he killed Danzō, and then proclaims his plans on destroying Konoha. Despite Kakashi's attempts, Naruto and Sasuke then clash with their Rasengan and Chidori. After they clash, Naruto remembers a time when even he thought of revenge against Konoha, and of how he eventually overcame it — by making bonds with Sasuke and Iruka Umino.
Before Naruto and Sasuke clash, Naruto is imagining how easily the roles between them could have been the opposite, thus seeing himself using Chidori while Sasuke using Rasengan.
In the beginning of this episode, there is an animation error:
Kakashi is fighting Sasuke. Sasuke is depicted with both of his wrist warmers when the one on his left was taken off during his battle against Danzō.
For this episode and part of the last, Sasuke had no pupils to show he was losing his eye sight, but when he clashes with Naruto near the end of the episode and look each other in the eye, Sasuke has his pupils. It's because he didn't lose it completely.