"Sasuke's Answer" (サスケの答え, Sasuke no Kotae) is episode 370 of the Naruto: Shippūden anime.
As Hashirama concludes the story of his battle with Madara and his vision of the village, he tells those present on site that he did not know how Madara survived after their battle. Sasuke iterates how ironic it was that his brother Itachi, who was from the Uchiha clan, and had never heard Hashirama's story directly from the source, was the one who had inherited his will so strongly. However, Tobirama notes that there had been several Uchiha throughout history which had transcended the limitations of their clan and put the village first; one such shinobi included his former subordinate Kagami Uchiha. The Second Hokage notes he had to find a way to mediate between clans and the village's well-being. In turn, both the Third and Fourth, note that they had fallen short of their predecessor, and the expectations people had of them respectively. Having heard all he needed from the Hokage, Sasuke comes to the conclusion that the village and people that Itachi sacrificed his life to protect should not be wasted, and decides to enter the battlefield in order to follow his brother's will, with Orochimaru following out of interest. Motioning to Tobirama to prepare to transport them, Tobirama informs his brother that they could not do so because they were bound. As they left the Naka Shrine, Suigetsu expresses his disinterest in the battle and tries to slip away, only to be met by a kick from Karin. She then yells at Sasuke for stabbing her but fails to contain herself when Sasuke apologises, and forgives him. As the Hokage prepare to make their way to the main battlefield, Hashirama directs his fellow Hokage to their respective faces on the Hokage Rock before expressing his curiosity as to what his old friend had been up to. Tobirama declares that he will stop Madara for good, and Hiruzen vows to go all-out this time. Minato, delighted that he will meet his son, promises to make up for not being there with a gift.
Sasuke's flashback to when Itachi told him he was weak because he lacked enough hatred aligned more with the manga, in which Itachi told Sasuke this after he cast Tsukuyomi on Sasuke and Jiraiya casting the Summoning: Toad Mouth Bind. In Naruto episode 85, Itachi told Sasuke this before either technique was cast.
There was a meteorological inaccuracy at the conclusion of Hashirama and Madara's battle. The sky was shown to be clear with some clouds floating around but it was raining. When raining, clouds cover the entire sky. This inaccuracy was not present in the manga.