Board Thread:Questions and Answers/@comment-24919788-20140509022515/@comment-1387259-20140512233248

This is a tough one. The main underlying fact about Zanpakuto that we know is that the Shikai and Bankai are related in one way or another. The two will never have polar opposites in powers. Even the strangest cases still follow this rule, e.g. Sui-Feng. Her Shikai and Bankai share the common theme of fast death. The methods the two do this are like night and day, but the underlying theme is the same. by this rule, Unohana's Shikai and Bankai both have to share a theme.

From what we know of her Shikai, Minazuki has the capability to turn into a large flying creature that can heal people by swallowing them (and eventually spitting them back out). So from this, we have the main ability of the Zanpakuto: healing. Because of the general rule of Zanpakuto, her Bankai should, in theory, do the same thing. We've seen very little of it, so we really don't know what it does. What we do know is that during her fight with Zaraki, she kept "killing and healing him" over and over again. From this, is that the Bankai possibly has the ability to resurrect (perhaps only on things that have . It's ability to kill was, most likely, just from the fact that it still is a blade with a sharp edge. Those hurt people. They also kill. My guess is that the ability to heal (probably upon stabbing) is completely controlled, meaning that she can resurrect with it when she wants to, and use it as a normal instrument of stabbing when she doesn't.