Who is Mephisto? The Demon Mephistopheles

Mephisto, or Mephistopheles, is a prince of Hell. One of seven such princes, Mephistopheles is a powerful force in the underworld. He appears in numerous works of fiction such as the legend of Faust and the video game series Diablo. Mephistopheles is evil by definition, and is sometimes even thought to be the devil himself.
Mephisto, prince of Hell