inhuman vs killer instinct

inhuman

adj
  • Transcending or different than what is human. 

  • Of or pertaining to inhumanity and the indifferently cruel, sadistic or barbaric behavior it brings. 

killer instinct

noun
  • The natural inclination to do whatever is necessary to succeed (including extreme violence) 

  • Used other than figuratively or idiomatically: see killer, instinct. 

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