diabolic vs incessive

diabolic

adj
  • Extremely evil or cruel. 

  • Showing wickedness typical of a devil. 

  • diabolic magic square 

incessive

adj
  • Fierce; cruel and aggressive. 

  • Insightful; deep and succinct; incisive. 

  • Intruding inward. 

  • Tending to incite or inflame; incensive. 

  • Intense and active. 

  • Synonym of inessive 

  • Continual or successive; unceasing. 

  • Critical and accurate; incisive. 

  • Included. 

  • Durative. 

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