Fluffys-nightmare
Ao no Exorcist. Begins a few months after the Illuminati Arc. All the Exwires have become Exorcists and one could say that all is well, but in Gehenna, trouble stirs in the shadows. Rumor has it that Satan had another child, that he banished into darkness for eternity. Some say that after centuries of biding his time, that Hell King betrayed Satan and fled to Assiah! Some even say that he is searching for the Heirs of the Blue Flame, to give them the secret to the Devil's destruction... Beware, the King of Shadows is coming... Hints of Am/Shie, Shura/Meph. Enjoy!
(I do not own Blue Exorcist)