User blog comment:Xilinoc/Ch. 547 - Peace from Shadows/@comment-1268838-20130904145545/@comment-5657895-20130904162638

Seems kinda stupid that Mayuri wouldn't warn anyone, though I guess Shunsui returning extra fast might be thanks to Mayuri.

Didn't Aizen hint at this in the Soul Society arc? The whole shadows thing? That's what I heard anyway.