User blog comment:Xilinoc/Ch. 566 (not out yet, but dis gon b gud)/@comment-24153155-20140129222822/@comment-11051098-20140130001632

Also relates to how Shûhei, Ikkaku and Yumichika appeared to be unaware about Mask's presence when he ambushed them.

As with every previous time we have seen NaNaNa, he only got a short presence and remains mysterious to us. And I personally didn't expect Äs to confront Rukia, but seeing as he almost killed her brother, I guess it's natural that he went after her to find out where Byakuya is.