User blog comment:B214/Volume 22 spoilers/@comment-185.112.105.215-20161011161249/@comment-86.174.158.212-20161013004931

I imagine Gods like Indra and Hades must be getting weary of how much power Issei and Vali are getting. So I wouldn't put it past one of them trying to release Samael as a way to get rid of Issei and Vail.