debuff vs lessen

debuff

verb
  • To make a character or unit weaker. 

noun
  • An effect that makes a game character weaker; a negative status effect. 

lessen

verb
  • To make less; to diminish; to reduce. 

  • To become less. 

conj
  • unless. 

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