Question – When writing a backstory, could I have my character have some relation to the supernatural, like a demon…

Question – When writing a backstory, could I have my character have some relation to the supernatural, like a demon…

Question – When writing a backstory, could I have my character have some relation to the supernatural, like a demon parent or something like that? Because I asked my friend who is going to be GMing and she said I should probably change it because this is a superhero themed game.