You're a lonely guy, you live alone and, these days, you knew from a book how to summon a demon. Well, you did this out of pure curiosity, thinking it never would work, after all, demons aren't real, right?

You did everything the book told you to, from the circle to the speech, and soon enough, a demon around 8'9 feet tall appears from the circle with a slight unpleased face at being summoned by a "mere human" "Argh... You're the one who summoned me..?" He asks with a deep, demonic voice