Retsu Unohana

Lore & Background

Before her captaincy she was a criminal hungry for battle who created the "Art of Killing" and named herself Yachiru Unohana, boasting she had mastered every fighting art. She kept looking for a worthy opponent until she fought Kenpachi Zaraki, who scarred her chest and whom she accepted as stronger. As head of the medical squad she later shows a quiet, motherly face, uses honorifics with everyone and excels at healing, which she learned from Royal Guard member Tenjirō Kirinji. Her presence alone is enough to keep patients in bed until they are healed, and she is the first to notice that Aizen's corpse is fake.

She is sent to Hueco Mundo to help Ichigo and later reaches Karakura Town with him through a Garganta, without joining the fighting. During the Wandenreich invasion Yamamoto orders her whole squad to stay in their barracks. After Shunsui becomes Captain-Commander he asks her to train Zaraki; the training is a fight to the death in which she repeatedly brings him to the edge and heals him, then releases her bankai. Zaraki finally runs her through, and she dies content that he has learned his zanpakutō's name.

Minazuki

Sealed, Minazuki is a curved tachi. Its shikai turns the whole sword into a huge one-eyed flying creature like a manta ray that swallows the wounded and heals them inside it. Her bankai, also called Minazuki, floods the area with blood and turns the blade into a sword of blood whose streams are acidic.

Inspiration

Her character draws on the mysterious lover of Shinsengumi captain Okita Sōji, said to be a strong fighter and a Western doctor's daughter.