Originally Posted by ask me anything
The guy flat out said Byakuya will die if he stays there, and that Unohana couldn't heal those people but he could. The arrogant way in which he was talking to Unohana was clearly meant to be condescending and degrading.
He's more condescending in the beginning. They appear to have a student/teacher relationship, so it was probably meant to be more playful than insulting. At the end he insists he take care of Byakuya and says "What you're meant to do now... is not healing."
I think she's going to be a major player this arc. Reminder her battle data is higher than Kyoraku and Ukitake's in the databook.