God Level {Highschool DxD X OC}

Hundreds of years ago a devil scientist cracked the code and was able to make advanced devils in order to put his species at the top of the food chain; and after injecting both himself and many others, as well as spreading it through the air both in Hell and on Earth he would do just that

...However because of how crazy and battle hungry they turned out to be, most of the population would be killed by God. They would then fight in the Great War between the Factions to rise on top again and lose yet another big portion of their population, rendering their population down to the thousands. Long after though they would then all die out after one of their own hunts them down, all before engaging in a battle with the final one, resulting in his eventual death.

That final super demon is who's story we follow, Ryo Kirishima. Sounds serious? Well Ryo here is just gonna go through DxD to do whatever he feels like. Things just got more interesting for him.