Hello, Author-san, I have an idea about which you could embody this story, something in between Toaru Majutsu no Index and High School DxD. I like the characters of Kamijo Touma, the author, you can make a fanfiction. The beginning of the plot after the Third World War (end of season 3) Touma will go to another world of dxd, Azazel finds him there, gives him a house and helps the main character, but there is one thing, Touma does not remember that he is from another world, he again lost his memory for the second time, he learned his name from a student the ticket of Akademgorodok. Maybe you can finally lose your virginity. By the way, I would like to see how Touma will fight with Olympus, I do not like these gods, the only one who can say I like it is Hephaestus, without him they have no weapons and treat like a slave, and I am generally silent about Aphrodite. I'd like to see Touma and Hephaestus team up to fight Zeus. The plot can be built in such a way that Hephaestus wants to leave Olympus, the Olympians do not want how they are without him.