Succubus 48-su

The key to saving the world—of all things—was his. Abel, the cleric of the hero's party. One day, a bolt from the blue struck him. "Save the world with your penis and semen." He thought it was a joke. But standing before him stood a succubus, the last survivor of the demon race said to be extinct. Suzuka, a girl with red hair and black horns, more beautiful than anything in the world, yet glaring at Abel with a barbed tone as if to devour him. The mission given to the two was only one: to complete the forbidden ritual of the '48 Succubus Moves,' which must be perfected through body against body. Between the fate of the world and the passionate night. The story of saving the world in the most secretive way begins now.

(Source: Lezhin, translated)