User blog comment:B214/Volume 22 spoilers/@comment-9595671-20160814045836/@comment-1359322-20160814054225

In EX which is 30 years later, Azazel, Sirzechs and the others are still fighting 666, so 666 won't be a factor for Ise's remaining high school life.

Hmm, they are known as 12 heinous criminals sealed in the Underworld, maybe someone unsealed them during the Rizevim incident.