Aggressor vs villain

Aggressor

noun
  • a citizen/subject of the fictional Aggressor state 

name
  • a fictional state created by the United States Army for maneuver and military exercise purposes in the 1950's 

villain

noun
  • In fiction, a character who has the role of being bad, especially antagonizing the hero. 

  • A vile, wicked person. 

  • An extremely depraved person, or one capable or guilty of great crimes. 

  • Any opponent player, especially a hypothetical player for example and didactic purposes. Compare: hero (“the current player”). 

  • A deliberate scoundrel. 

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