heroism vs undefeatableness

heroism

noun
  • The qualities characteristic of a hero, such as courage, bravery, fortitude, selflessness, etc.; the display of such qualities. 

undefeatableness

noun
  • The quality of being undefeatable. 

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