Highschool SxS (Patreon)

The story of how Issei came to be a devil and part of Rias's peerage is well known to any who follow it: The young lad is killed by Raynare, a fallen angel who dated him and earned his trust. In his dying moments, he pledges allegiance to Gregory, becoming part of her peerage.

But how different would the whole of her peerage be, as well as the world surrounding Issei, if she were something other than a devil? Say, a succubus. And all those who join her have to become succubi as well.

For Issei, it certainly makes his school days, and body, undergo some changes...