Byakuya's anger, collapse of the Kuchiki family

The Sixth Division is unwinding on the grounds of the Kuchiki estate, a rare gesture from Byakuya meant to let his people recover after the recent chaos with the sword spirits. The calm breaks when a black-bladed swordsman and a goat-legged creature crash the celebration. Rukia reaches for her weapon only to find it missing, and she is nearly overrun before Sode no Shirayuki and Senbonzakura, both still walking around in physical form, step in and drive the pair off. One attacker collapses and reverts to an inert blade.

Puzzled that the spirits never turned back into ordinary swords, the group brings their questions to Mayuri. He explains that these beings are corrupted sword spirits whose owners perished after Muramasa loosed them, leaving them stranded as something between spirit, Shinigami, and Hollow. He coins a label for them and warns that each one carries strength on par with a released final form. Byakuya then places Rukia in charge of the problem and lends her Senbonzakura.

Acting on the theory that the escaped creature is drawn to festivities, Rukia stages a party at the Tenth Division to bait it out. The scheme mostly produces drunken squad members and an embarrassed captain, but the spirit eventually storms the barracks. Rukia, backed by her partner, corners the whirling attacker and freezes it solid, capturing it for study. Afterward, Ukitake cautions that similar sightings are multiplying across the Soul Society.

The rogue sword pair assaults the Kuchiki manor, and Rukia discovers her Zanpakutō is absent when the fighting begins. Mayuri reveals the nature of these corrupted spirits, names them, and pegs their power at final-release level. Byakuya assigns the investigation to Rukia and leaves Senbonzakura at her disposal. A staged party fails to lure the survivor at first, but it eventually attacks the Tenth Division, where Rukia and Sode no Shirayuki subject it to a freezing finisher and take it prisoner. Ukitake confirms that masterless spirits are appearing in growing numbers.

This installment carries no manga source and belongs to the anime-original run built around the Beast Swords campaign. A quieter thread sees Sode no Shirayuki confess that she fears she is nothing more than a weapon, prompting Rukia to remind her that they have stood together through her hardest moments as genuine partners. The comedic closing segment features Gin hosting the Arrancar Encyclopedia, joking that the explanation reached him only after being relayed through a long chain of Hollows.