[@Ace of flames01] What I was asking is if there was a story-relevant reason for their gender? In other words, does it have to be a PRINCE of Darkness, or could a PRINCESS of Darkness serve the same purpose in the story? Based on your answers so far, I'm starting suspect that the answer is yes, that character role has to be male.

You also mixed up one of my questions. I was asking about the difference between dark magic and BLACK magic, not BLOOD magic.