The word Faustian is perfect for describing a circumstance in which a person compromises her beliefs or morals in order to achieve some kind of success.
Faustian is inspired by the literary character Faust, who was based on an actual German Renaissance-era astrologer, magician, and alchemist. In the mythology around the character of Faust, he is described as having sold his soul to the devil for "unlimited knowledge and worldly pleasures." Both Christopher Marlowe and Goethe used Faustian characters in their plays, and to this day people talk about making a "Faustian bargain," sacrificing personal integrity for something desirable.