User blog comment:Jopjopjop/Volume 20 Spoilers/@comment-201.79.38.59-20150808012315/@comment-1359322-20150808124152

And what makes you think Ise will be the one to defeat 666?

666 has only been unsealed at the end of the Volume and Ise is already out because of using the Diabolus Dragon. Also Volume 21 is on Vali, it might end up Vali being the one who beat 666.