After a grueling battle, you (and your teammates, if you have them) have defeated and mortally injured a demon-motif villain (use whoever fits in your campaign). Just before he expired, the baddy says the following: "Celibrate your victory while you can fool(s), the seed of my rebirth has already taken root."
He then cackles a last maniacal laugh, his eyes unfocus and roll back in his head, and he collapses limp as a ragdoll as his spirit abbandons his lifeless body.
Sometime later, you somehow find out that a young woman known to have had -ahem- "intimate contact" with the aforementioned villain is pregnant. How would your character react?