Mephistophelean vs nefarious

Mephistophelean

adj
  • Showing the cunning or ingenuity or wickedness typical of a devil. 

nefarious

adj
  • Sinful, villainous, criminal, or wicked, especially when noteworthy or notorious for such characteristics. 

How often have the words Mephistophelean and nefarious occurred in a corpus of books? (source: Google Ngram Viewer )