High School Dxd: Rise of the New Dragon God (Born Of A Legend)

The long battle of Ophis and Great Red caused both of them to lose half of their power. And that power unknowingly why entered Mrs. Hyoudou's baby just seconds after that baby was given by a goddess' blessing. What will happened when the strength of the two strongest being merge in one human?
I bet you've already heard about the story of a perverted young man with a longinus inside of him who was turn by a devil when he was killed by his girlfriend right? But this is a different story, one about a boy who was foretell in an ancient prophecy that will decide the fate of both the world we know and the world we didn't know.
Some addition title (there's some title given in this story) :
Great Red = primodial of dream or hope
Ophis = primodial of nothingness and part of void
trihexa (666) = primodial of chaos or creator of universe
(but don't misunderstood me, what I wrote isn't a new better version of Issei Hyoudou, but the same one in the original series. The one who already realize his responsibility as someone with power..... And there will be some element from Percy Jackson. Enjoy.)
Disclaimer, High school dxd wasn't mine, the same with Percy Jackson and the other element. The only thing mine was the plot and idea of this story.