Lilim wants to Lv up♥

One night, a beautiful girl suddenly appeared in my room. She wasn’t just dressed in a revealing and sexy outfit, but she also had horns and a tail. Lilim, a self-proclaimed succubus, came to the human world in order to level up; my long-hoarded sexual desire was just the perfect target for her. After negotiations, it was decided that this mysterious succubus would start a one-month live-in contract with me. Using my help, what kind of a succubus would Lilim become?