The first Madam Satan was a woman named Tyra, who was engaged to a man whose parents did not approve of the impending marriage. When she found out about their disapproval she murdered them. However, as they were dying they were able to tell their son that his fiancee was the murderer.
The son executed his revenge killing Tyra who ended up in hell working under Satan. Her job was to seduce men into giving their souls to Satan. This worked pretty well since her powers included hypnotic control over all men as well as the ability to kill men with a single kiss. (Wikipedia)