"We are born if an ancestor laid with a powerful and evil outsider, be it a devil, a demon or some other dark

"We are born if an ancestor laid with a powerful and evil outsider, be it a devil, a demon or some other dark creature. Many mortals do this, believe me – either for power or pleasure. This heritage can be hidden for many generations. And it can manifest in many ways. – It's difficult to find two similar tieflings."