You Are Forbidden to Die

Pierced by Nejibana, Rukia loses consciousness and returns in memory to a training trip with the living Kaien Shiba at Mount Koifushi. He wakes her with a slap, spars until he disarms her, and teases her growling stomach, while she recalls how she once doubted she belonged in the Gotei 13, weak in Zanjutsu and only average in Kidō. Kaien tells her she exists to fight and to protect, and when she asks what she is protecting, he turns to their captain Ukitake's belief that every struggle comes down to the heart.

Raising his fist between them, Kaien argues that the heart is not held within the body but born between people who grow close, so that one who is truly alone can have none. He urges Rukia never to fight alone, explaining that a dead Soul's body dissolves into the Reishi of Soul Society while the heart stays with those left behind, which is why she must never die alone. In the present, Rukia grips Nejibana as ice climbs its length, lifts her shattered Sode no Shirayuki, and performs San no mai, Shirafune, growing an icy blade that spears Aaroniero's head and capsule. She tells him he holds only Kaien's body, for the heart remains with her, then shatters the capsule with a downward stroke.

A flashback restores Kaien's lesson that the heart resides with one's companions rather than inside the body, and that a warrior must never die alone. Drawing resolve from the memory, Rukia awakens, reforms her broken blade through San no mai, Shirafune, and impales Aaroniero, declaring that Kaien's heart has always stayed with her before destroying his capsule.

The 268th chapter carries the Japanese title 君 死にたもうこと勿れ, rendered by Viz Media as You Are Forbidden to Die and translating to "You must not die." Collected in volume 30, THERE IS NO HEART WITHOUT YOU, it belongs to the Hueco Mundo arc and was adapted in episode 160, Testament, Your Heart is Right Here....