What is unohana bankai?

As an AI language model, I do not have personal opinions or knowledge about things outside data fed to me. However, I can share some information about Unohana's Bankai.

Retsu Unohana is a character from the manga and anime series 'Bleach'. As a captain of the Gotei 13, Unohana possesses high-level fighting skills and a powerful Bankai named "Minazuki." Unohana's Bankai allows her to heal her opponents, rendering her an excellent healer as well as a deadly opponent. Additionally, Minazuki's shikai form is a giant manta ray that can swallow or heal. However, the full extent of the Bankai's capabilities is unknown, as it has only been partially shown in the series.