daemon vs guardian angel

daemon

noun
  • An idea depicted as an entity. 

  • A process (a running program) that does not have a controlling terminal. 

guardian angel

noun
  • A tutelary angel watching over a particular person in monotheistic contexts. 

  • A person who watches over another. 

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