Highschool DXD: The Black Dragon Emperor

Everyone knows that there are 13 Longinus Sacred Gears in the world, but what if there was a secret cursed Longinus that holds the power to either protect the world or destroy it. Follow the story of Akira Hyoudou as he joins forces with various people while he also discovers the dark secret about his past.

Disclaimer: I don't own Highschool DxD and any elements from Fairy Tail, Testament of Sister New Devil, and Blue Exorcist, just this story, and my. Also, I can't stress this enough, but this story is for mature audiences only so unless you are 18 and up don't read it if you are bellow it.

A/N: This story will follow the light novels and the anime of Highschool DxD, but I'll be changing a few things from the series. Also, Issei in this story will be a lot different than in canon and won't be a mega perv. My oc and Issei will also have a harem in this story.