poetic justice vs self-flagellation

poetic justice

noun
  • The rewarding of virtue, and the punishment of vice, especially in an ironic manner. 

self-flagellation

noun
  • The practice of whipping oneself as penance for sins. 

  • Intense feelings of guilt. 

How often have the words poetic justice and self-flagellation occurred in a corpus of books? (source: Google Ngram Viewer )