Where does “Faustian” come from?

Faustian (English) comes from German Faust, from Middle High German fūst, from Old High German fūst, from Proto-West Germanic fūsti, from Proto-Germanic funstiz, from Proto-Indo-European pnsti-, from Proto-Indo-European pnksti-, from Proto-Indo-European pénkʷe — five.

Faustian (English): Of or pertaining to Faust, especially in the sense of being willing to abandon one's principles or values in order to pursue knowledge, wealth or other benefits