The Battle

Inside Muken, Kenpachi Zaraki keeps blacking out mid-fight against Retsu Unohana, coming to as they trade blows. Their clash stirs a memory centuries old: Unohana, bored with her own strength and hunting the Rukongai for worthy opponents, once crossed blades with a young Zaraki atop a mountain of corpses. He wounded her, and the encounter brought them both an unmatched thrill, but she never expected the boy to shackle his own power because of it.

Unohana reveals the truth of Zaraki's long suppression. Devastated that his first real rival was weaker than him, he unconsciously buried his strength to stay at her level, which is why his fights against Ichigo and Nnoitra ended so narrowly. Resolving to kill and heal him repeatedly until he surpasses her, she wounds and revives him over and over as he steadily breaks free of the limits he set on himself.

Unohana heals herself with Kaidō and activates her bankai Minazuki, drowning the arena in blood-red liquid she shapes into swarming blades. As Zaraki grows strong enough to outmaneuver her, he finally names the phenomenon she taught him and thanks her for showing him what real battle feels like. Concluding that only one Kenpachi can exist in any era, Unohana lets him impale her, praises his performance, and dies content, passing her power and the title fully to him. Afterward, the spirit of his Zanpakutō speaks to him for the first time and gives her name.

Meanwhile, Ichigo and Renji arrive at the Hōōden and are subjected to Ōetsu Nimaiya's flashy antics before he drops them into a pit to face the Asauchi, the nameless blank Zanpakutō that every Shinigami imprints upon to forge their weapon. After nearly three days of fighting, Nimaiya passes Renji as a true Shinigami but fails Ichigo, declaring he was never chosen by an Asauchi. He sends Ichigo home through the Chōkaimon, telling him he must first discover his own roots.

The tenth Thousand-Year Blood War episode and 396th overall in the anime, it adapts material from chapters 522 through 528 and concludes the Zaraki versus Unohana duel alongside the start of Ichigo and Renji's royal training. The anime expands both Unohana's Minazuki assault and the Asauchi sequence, and trivia notes a continuity wrinkle with the timing of Unohana's chest scar established in an earlier episode.