angel of death vs martyrization

angel of death

noun
  • A type of serial killer who is employed as a caregiver and kills people under their care. 

  • A shinigami. 

  • The Grim Reaper. 

  • An angel which attends to death, collecting souls at death, ending life at the appointed time of death. 

  • Azrael. 

  • Death, one of the Four Horsemen of the Apocalypse. 

martyrization

noun
  • The act or process of martyrizing. 

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