Blue Exorcist Vol. 22 (manga)

The seals binding the artificial Gehenna Gate are broken, and the world is gripped by demonic chaos! The Exwires try to figure out what to do without Rin and Yukio, the Knights of the True Cross scramble to regroup and everyone seems lost. As nations around the world struggle to contain the outbreaks, Rin faces Mephisto, demanding to hear about his past. Mephisto couldn't be more delighted to show Rin what happened all those years ago, but as Mephisto warns him, the story can only end in tragedy...