Risk

Having left Sasuke his parting words, Itachi's spirit slips free of the Impure World Reincarnation, and across the war's many fronts the other summoned souls begin dissolving as well. The five Kage sense the shift and marvel at whoever unraveled the technique, with Ōnoki declaring that person a savior of the shinobi world. Recovering command of his body, Dan asks Chōza to lower the Four Violet Flames Formation that has him boxed in. Once the barrier drops, Chōza recognizes the hand seals Dan formed, grasps his aim, and urges him to race to Tsunade. Channeling his Spirit Transformation Technique to seize his own rising soul, Dan reaches Tsunade just in time to possess her body and shield her from Madara, who, though himself being dragged back by the fading reincarnation, still makes one last desperate bid to cut down the Kage. Meeting Tsunade within her own mind, Dan promises to await her in the next life while warning her not to hurry after him, and he departs leaving behind the rest of his chakra, which revives her Strength of a Hundred Seal. Back among the living, the Kage puzzle over why Madara has not frozen along with the others. He explains that a reincarnated soul who knows the seals to void the summoning pact can sever the bond with its caster, and he does exactly that, telling them to warn his summoner against tossing around forbidden techniques so carelessly.

Itachi's soul is released, and the other reanimated shinobi begin returning to the afterlife. The Kage realize the technique has been undone and praise its unknown ender. Dan has Chōza free him, then possesses Tsunade to save her from Madara and restores her Strength of a Hundred Seal before vanishing. Madara performs the seals to cut ties with his summoner, choosing to leave on his own terms.

This is chapter 591, printed in volume 62 during the Fourth Shinobi World War: Climax. The unraveling of the reincarnation traces back to Itachi's earlier confrontation with Kabuto.