7. Forneus

According to The Lesser Key of Solomon, an anonymous book of spells that was compiled during the mid-seventeenth century and focused on demonology, Forneus is the Great Marquis of hell and has twenty-nine legions of demons under his command. He promises fame, popularity, acceptance, and love from your friends and enemies (always with a catch of course) and is normally depicted as having an attractive human form. However, he can display a grotesque and frightening demonic form when he gets angry.