mephistophelean

Adjective

• showing the cunning or ingenuity or wickedness typical of a devil
  • devilish schemes
    
  • the cold calculation and diabolic art of some statesmen
    
  • the diabolical expression on his face
    
  • a mephistophelian glint in his eye
    

Related words

• Synonyms: 
  devilish , diabolic , diabolical , mephistophelian