gain mastery over vs overwhelm

gain mastery over

overwhelm

noun
  • The state or condition of being overwhelmed. 

verb
  • To overpower emotionally. 

  • To cause to surround, to cover. 

  • To engulf, surge over and submerge. 

  • To overpower, crush. 

How often have the words gain mastery over and overwhelm occurred in a corpus of books? (source: Google Ngram Viewer )