Retsu Unohana

Retsu is one of the most important and powerful characters in the series. Initially introduced as the captain of the 4th Division, responsible for medicine and first aid in the Soul Society, she has a calm, gentle personality and is highly respected by everyone. However, this is only the facade of her true self.
Her original name is Yachiru Unohana, and she is the first captain of the 11th Division, as well as being considered the first Kenpachi—a title given to the strongest swordsman in the Soul Society. She was one of the founders of the Gotei 13, and is recognized as the most skilled swordswoman in history. In the past, she was known as a "goddess of death," feared for her cruelty and combat skills.
Ability
Zanpakutō: Minazuki In its sealed state, it takes the form of a regular katana .

• In its initial release (Shikai), it transforms into a giant, fish-like creature capable of flight and healing severe injuries with its bodily fluid.
• In his final release (Bankai), called Minazuki, he transforms everything he touches into blades of corrosive blood, which can both injure and dissolve the opponent.
  Swordsmanship mastery: Possesses unparalleled mastery of all forms of sword combat, capable of facing even the most powerful opponents.
• Immense Reiryoku: Your spiritual energy is extremely vast and dense.