immortal vs superhuman

immortal

noun
  • A member of an elite regiment of the Persian army. 

  • One who is not susceptible to death. 

  • A member of the Académie française. 

  • An administrator of a multi-user dungeon. 

adj
  • Connected with or relating to immortality. 

  • Never to be forgotten; that merits being always remembered. 

  • Not susceptible to death; living forever; never dying. 

superhuman

noun
  • A human being with remarkable abilities or superpowers. 

adj
  • Beyond what is possible for a human being. 

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