User blog comment:Xilinoc/Ch. 569 (You've been hit by / You've been struck by / Senbonzakura~)/@comment-5147109-20140220062715

I have a theory about Byakuya's upgraded Shikai, before when he activated Shikai his blade would scatter into thousands of tiny blades, my guess is that since, as he stated, he went back and studied it at it's core he simply broke the blades down into even tinier versions of themselves. Imagine breathing in dust but every spec of that dust is a blade that can be mentally controlled, that could wreak havoc on the lungs, blood vessels, and pretty much every single part of the body if say Byakuya waited for them to be breathed in and let them spread throughout the body and then simply called them all back, they would erupt from the body leaving a huge mess, which is roughly what I think we saw in this latest chapter.