User blog comment:Xilinoc/Ch. 572 (inb4 "Kenpachi doesn't have Shikai")/@comment-11062267-20140312180606

I may be alone in this but I was kind of hoping Zaraki would come crashing in (which he did) and then shank the kid in an almost accidental fashion, as if he didn't realize the kid was there and then just happened to find the kid impaled on his Zanpakuto. End of battle. Of course, I only feel this way because I already REALLY hate this kid.

On a more practical note, I realized that neither Isane, Yachiru, nor both Quincies sensed Zaraki's arrival. Zaraki normally had a monstrously uncontrolled reiatsu that could be felt even over vast distances. However, no one noticed Zaraki approaching until he scolded Yachiru then came busting through the walls. Perhaps Zaraki has, in addition to improving his ability to sense and locate reiatsu, gained the ability to control his reiatsu?