harsh vs relentless

harsh

adj
  • Severe or cruel. 

  • Unpleasantly rough to the touch or other senses. 

verb
  • To negatively criticize. 

  • To put a damper on (a mood). 

relentless

adj
  • Unrelenting or unyielding in severity. 

  • Unremitting, steady and persistent. 

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