Blue Exorcist Angelic convergence

Assiah, the realm of humans, and Gehanna, the realm of demons. Normally, these two dimensions would never intersect but having possessed all the material substances, the demons are now intruding on the material world. But among the human race, there are those who can exorcise such demons. To combat the Devil himself, God sent his most powerful Angle to produce a weapon to fight back against the incoming threat.