Ao no Futsumashi - Chapter 109
Tags:
Adapted to Anime, Ao Ex, Ao no Exorcist, Aoex, Blue Exorcist, Dead Family Member, Demon, Demon Child, Devil, Exorcism, Lam Hỏa Diệt Quỷ, Modrý Exorcista, Secret Identity, Special Ability/ies, Swordsman, Twin, Синий Экзорцист, المعوذ الأزرق, جنگیر آبی, เอ็กซอร์ซิสต์พันธุ์ปิศาจ, 蓝色的除魔师, 藍色的除魔師, 青エク, 青の祓魔師
The flashback segment works so very well, where in other stories it would be treated as mere exposition by the readers, because Blue Exorcist has done an excellent job making the consequences of this flashback into the tapestry of the present day.
You want to know where all the pieces fit.