guardian vs overman

guardian

noun
  • Someone who guards, watches over, or protects. 

  • A superior in a Franciscan monastery. 

  • A person legally responsible for a minor (in loco parentis). 

  • A person legally responsible for an incompetent person. 

  • A major or final enemy; boss. 

overman

noun
  • A person who supervises others; a supervisor, especially in a mine. 

  • A person with great powers; a superman. 

verb
  • To provide with too many personnel; overstaff. 

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