Mephistophelean vs devilish

Mephistophelean

adj

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

devilish

adj

  • Resembling a devil. 

  • Extreme, excessive. 

  • Characteristic of a devil. 

adv

  • Devilishly; very; exceedingly. 

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