Blue Exorcist, Mephistopheles, a character in this Japanese anime
Based on the original background setting of this anime, I will write a fanfic about Mephisto, the original heroine. In the anime, Mephisto is the Lord of Time, one of the Eight Demon Lords, who can control time. The anime mentioned that he participated in an artificial human project hundreds of years ago, because the demons do not have a powerful container in the material world, so they have to constantly replace them. Here I set the background: Mephisto Te's story began three hundred years ago in the Vatican Palace. The entire knight order was trying to find a way to fight against the devil. So the Eight Lord Kings were some of the kings who stood on the side of humans. They possessed humans and combined with humans. They gave birth to children with powerful powers and were called giants. They then taught these people how to subdue demons from generation to generation. This is the birth of the Knights of the Right Cross!
Concept: The story is set three hundred years before the animation background