Who is Mephistopheles in the play Dr Faustus?

From the Hebrew, mephitz, destroyer, and tophel, liar. A devil of craft and cunning. He is the devil who comes at Faustus' summoning, and the devil who serves Faustus for 24 years. In lore, Mephostophilis (also spelled Mephistopheles, or Miphostophiles, and also called Mephisto) seems to be a relative latecomer in the recognized hierarchy of demons. He possibly was created for the Faustus legend.

In Marlowe's play, Mephostophilis has layers to his personality. He admits that separation from God is anguish, and is capable of fear and pain. But he is gleefully evil, participating at every level in Faustus' destruction. Not only does Mephostophilis get Faustus to sell his soul; he also encourages Faustus to waste his twenty-four years of power.