What is beyond bankai?

Beyond Bankai is a term used in the anime and manga series, Bleach. It describes a state that a Soul Reaper (Shinigami) can attain after releasing their Bankai powers. In this state, the Shinigami has reached the pinnacle of their power and has surpassed the limits of a regular Bankai.

The term was first introduced during the fight between Ichigo Kurosaki and Sosuke Aizen, a powerful Shinigami captain. During the fight, Aizen reveals that he had already surpassed the limits of his Bankai and achieved a form beyond Bankai.

There is no specific description of what this state entails, except that the Shinigami gains immense power and abilities that far surpass their regular Bankai. It is suggested that this state is achieved through intense training and unlocking the full potential of the Shinigami's spiritual energy.

However, beyond Bankai has only been achieved by a handful of characters in the Bleach series and is considered a rare and exceptional feat.