atrocious vs diabolic

atrocious

adj
  • Frightful, evil, cruel, or monstrous. 

  • Very bad; abominable, disgusting. 

  • Offensive or heinous. 

diabolic

adj
  • Extremely evil or cruel. 

  • Showing wickedness typical of a devil. 

  • diabolic magic square 

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