The Burden

Kakashi comes upon the fallen forms of Kiba, Akamaru, Lee, and Sai scattered along a forest trail, and manages to rouse Kiba just long enough to learn which way Sakura went. Reaching the bridge, Sakura tells Sasuke that she has walked away from her village and wants to stand at his side. He counters that his purpose is Konoha's destruction, then dares her to earn a place by killing Karin, dismissing the captured medic as an easy replacement. Sakura draws a kunai and steps close, but she cannot bring herself to do it.

Seizing the moment, Sasuke gathers lightning in his palm and lunges to cut her down from behind. The strike never lands, blocked by Kakashi, who is shaken to realize his former pupil truly meant to kill one of his own comrades.

Kakashi sends Sakura to move Karin out of harm's way and treat her, since the prisoner holds a wealth of intelligence on their foes, then squares off against Sasuke himself, feeling accountable for how badly matters have spiraled. He recalls how the Third Hokage kept a stubborn tenderness for Orochimaru and was still forced to fight his former student to the death, and only now does he understand that same grief. Sasuke unleashes concealed shuriken, which Kakashi shuts out with an earthen wall, before an aggressive follow-up drives Kakashi off the bridge entirely.

Sneering that no one outside the Uchiha should wield the Sharingan, Sasuke summons his Susanoo and looses an arrow. Kakashi twists it out of existence with Kamui, revealing his own awakened Mangekyō, and moments later Sasuke's vision blurs and his techniques abruptly fail.

The clash closes with Sakura slipping behind Sasuke, her memories of their genin days freezing her hand once more. He grabs her by the throat and pries the blade away, and with Kakashi spent from overusing his eye, only Naruto's last-second arrival snatches Sakura clear of the killing blow. The broadcast carries a handful of animation slips: Kakashi's Mangekyō is drawn as a red pattern on black, an error fixed the following week, and Sasuke's Susanoo appears with the wrong number of fingers, a misplaced object in its grip, and incorrectly shaped teeth.