User blog:Scott swag/How stong is Captain Unohana?

It seems that even though she is extremly kind-hearted and polite, people are scared of her. Would that be because if she gets mad she will attack them. Even Jūshirō Ukitake and Shunsui Kyōraku are scared of her in the TBTP arc. So please tell me how strong she is, we haven't even seen her fight in the series.