User blog comment:Xilinoc/Ch. 681 - THE END TWO WORLD/@comment-11293956-20160707191829/@comment-3185063-20160709095724

Book of the End might be like Mimihagi: Outside of Yhwach's vision. Book of the End has the ability to alter one's history, which effectively causes changes to the future.

Book of the End can also work in a way that makes inanimate object become traps just by Tsukishima inserting that kind of information into them, a power demonstrated during his fight with Buyakuya.

To sum it up this way: "changing the past changes the future."