User blog comment:Xilinoc/Ch. 626 - THE HOLY NEWBORN/@comment-5303512-20150514165526/@comment-5693502-20150514184051

Yhwach probably has an Achilles Heel that we just haven't been informed of yet. Odds on that Urahara or Aizen works out what it is and exploits it (after Ichigo has used his Plot powers to weaken Yhwach).