Synopsis
The plot revolves around Allen Walker, an exorcist, in the midst of the an imaginary 19th century Europe . Allen is a member of the Dark Religious Organization, which contains exorcists, connected with Vatican . The mission of the Dark Religious Organization is to stop The Millennium Earl, an evil demon-like entity intending to cleanse the world by destroying all the human in it in the manner of Noah's great flood.
The exorcists themselves are special people gifted with compatibility with Innocence, divine substance created in the ages past to combat the Earl's minions, the Akumas. It is said that there are exactly 109 units of Innocence scattered around the world. Once an Innocence finds its compatible person, it will evolve to become a weapon to fight the Akumas.