seraph vs virtuous

seraph

noun
  • A six-winged angel; one of the highest choir or order of angels in Christian angelology, ranked above cherubim, and below God. They are the 5th-highest order of angels in Jewish angelology. A detailed description can be found at the beginning of Isaiah chapter 6. 

virtuous

adj
  • Full of virtue, having excellent moral character. 

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