Evolution?! The Menace of the Final Sword Fiend

While cleaning up a cleaver-wielding Tōjū in the Seireitei, Kazeshini watches it collapse and revert to its sealed form without ever taking a fatal blow, alerting him to a hidden threat. He gathers Saru, Hebi, Hōzukimaru, and Ruri'iro Kujaku and explains the danger: a minotaur-like Tōjū named Kirikaze can drain the Reiryoku of other Zanpakutō Spirits and, unlike most, is powerful enough to surpass his former master, whom he always resented. With no one to restrain him, Kirikaze cannibalizes fellow Tōjū to swell ever larger, dissolving into mist to slip past attacks.

The Zanpakutō Spirits confront Kirikaze in force but find his mist form nearly untouchable, and when Ruri'iro Kujaku tries to drain him in return, the flow reverses and nearly consumes Ruri'iro Kujaku until Kazeshini cuts the connection. Just as the exhausted spirits falter, their Shinigami partners arrive: Renji, Hisagi, Rukia, Rangiku, Momo, Izuru, and Nanao, who had known the truth all along. Izuru binds Kirikaze with Sajō Sabaku while the spirits and Shinigami combine their strength, cutting off his ability to turn to mist. A weakened Kirikaze is finally obliterated when Renji unleashes Hihiō Zabimaru and fires Hikotsu Taihō, powered by the last Reiryoku of every spirit.

Renji drives home the arc's central lesson, that a Zanpakutō Spirit and Shinigami are only truly strong when paired, splitting their energies otherwise leaves them vulnerable, an insight the spirits should have learned from Muramasa. The spirits had deliberately hidden the mission from their partners, believing Kirikaze too dangerous, but the Shinigami had sensed their limits reaching their end. In the aftermath, the manifested Zanpakutō Spirits vanish for good, their forms sustained only by Muramasa's fading power, though Rangiku and Momo reassure everyone that the spirits remain within their blades.

A lighter interlude follows the Zanpakutō Spirits and lieutenants sharing food and sake at a bar, with Haineko playing the mature woman and a drunken Rangiku carried home, before the group reunites to end the Tōjū threat.

Episode 265 is anime-only and part of the Beast Swords arc, adapting no manga chapters. It aired in Japan on April 6, 2010, and in English on August 5, 2012, opening with Anima Rossa and ending on Tabidatsu Kimi e. A Shinigami Illustrated Picture Book segment finds Ichigo bored in Las Noches and begging Ulquiorra to resume their fight, only for Nel to scold him for acting like he is no longer the main character while Ulquiorra slips away to Orihime's side.