martyrdom vs shinigami

martyrdom

noun
  • The condition of a martyr; the death of a martyr; the suffering of death on account of adherence to the Christian faith, or to any cause. 

  • Extreme suffering, affliction; torment; torture, especially without reason. 

shinigami

noun
  • A deity and/or personification of death. 

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