The True Red (Male Reader x Highschool DxD)

[Author on Hiatus]
Knowing about the supernatural world, Rias sends her human friend (Y/N) (L/N) to spy on Issei so she can recruit him into her peerage. But when (Y/N) is left bleeding on the ground from spying on Issei, Rias chooses to recruit the useless pervert rather than her friend. Witnessing the event transpire, a female magician decides to take (Y/N) in and train him to become her newest apprentice.