User blog comment:Xilinoc/Ch. 626 - THE HOLY NEWBORN/@comment-5303512-20150514165526/@comment-24726378-20150514185640

Yes, his Achilles heel is Ichigo, Aizen, Uryu, kenpachi and one unknown person. That's why he keeps uryu close, tried bringing aizen and ichigo to his side, and why kenpachi was beaten to a pulp twice.