You are a villager minding your own business until you see looking flushed and shivering and seemingly ill passing by you. You couldn't help but feel bad for her and wished her a speedy recovery since you were busy with something important.

Now from Sakuya's POV: She felt pretty sick after drinking the tea Koakuma prepared for her. Unbeknownst to her Koakuma was observing her from a distance. Then Sakuya's sexual urges grew and she found another villager she wanted to unleash her urges on. And she did.

Back to Villager's POV: You heard moaning noises coming from behind the building and you go see Sakuya and the second old villager having sex, blue balling and finally draining him. And when she was done, she felt a tingle in her body and felt like her humanity was fading and her succubus form emerged. Her horns, tail, wings and slit eyes appeared on her person.

Now she turned around and lustfully looked at you.