User blog comment:Primeramizery/What could Mayuri be working on in his lab?/@comment-4207271-20130709084205/@comment-11051098-20130709135222

I don't consider her abilities, neither her Bankai, properly explained.

The fight did awaken Kenpachi's Zanpakutô, or rather, release his full potential and for the first time make him able to hear his Zanpakutô calling for him.

It was only mentioned that Kira's reiatsu vanished. Unohana apparently died too. But if Mayuri is resurrecting one of them, Unohana would by far be the most logical choice. The master healer, oldest remaining captain and has tremendous power. Killing her off would be a waste, especially when Kubo let Byakuya survive his injuries, which were far more serious than a sword stabbed through the chest.

I mean, whatever Kira can do, like healing and fighting, Unohana has hundreds of years more experience at. She was also said to have mastered every sword fighting style in the world, I think even before she became the first Squad 11 captain.