pertaining to or resembling or befitting Faust or Faustus especially in insatiably striving for worldly knowledge and power even at the price of spiritual values; "a Faustian pact with the Devil"

Something that is faustian refers to a wider interpretation of the events of Faust by Johann Wolfgang von Goethe. In part one of Goethe's Faust, the central character's pact with the devil allows him to have energy, life and youth unless he becomes so entranced by the passing moment that he wishes that things will never change. When Faust stumbles unthinkingly into that wish, his world and his life are forfeit to Mephistopheles.