itself vs us

itself

pron
  • it; used to intensify the subject, especially to emphasize that it is the only participant in the predicate 

  • The door itself is quite heavy. 

  • it; A thing as the object of a verb or preposition that also appears as the subject 

us

pron
  • Me and at least one other person; the objective case of we. 

  • Me. 

  • Our. 

  • Me (in all contexts). 

det
  • The speakers/writers, or the speaker/writer and at least one other person. 

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