The Devil Figure in Goethe, Boito, and Gounod

Faust written by Johann Wolfgang von Goethe is a worldwide famous master piece. It has been not only translated into many other languages, but also used as basis of other works such as opera, music piece, drama, movie and so on. After I read and watched Goethe’s Faust, Arrigo Boito’s opera Mefistofele and Charles Gounod’s opera Faust, I found that the drama’s protagonist is not the Faust what we think normally, instead it is actually another figure