User blog comment:Xilinoc/Ch. 565 (Mangapanda is run by lazy barnacles)/@comment-5847836-20140125014044/@comment-2211792-20140125053750

Hollows are souls who lost their hearts, and Quincies are humans who have a piece of Yhwach in their souls. No matter how I strain my brain, I still can't figure out what exactly makes one dangerous to another. Could be a case of Magic A Is Magic A, or maybe this weakness was an intentional part on Yhwach's behalf. As in, he wants Quincies to have no choice but to destroy Hollows, for whatever reason.