slow burn vs soreness

slow burn

noun
  • A gradually increasing feeling of anger or frustration. 

  • A romantic story (especially a work of fan fiction) in which the central relationship develops slowly. 

adj
  • Developing slowly over the course of the story. 

soreness

noun
  • The property, state, or condition of being sore; painfulness. 

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