Abaddon vs Niflheim

Abaddon

name
  • The destroyer, or angel of the bottomless pit; Apollyon; 

  • Hell; the bottomless pit; a place of destruction. 

Niflheim

name
  • In Germanic and Norse cosmology, the Norse underworld, location of the domain Hel and of the realm of Hel, the goddess of the dead. 

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