never again vs no more

never again

adv
  • At no time in the future; usually said of a negative event, practice, etc which should not be allowed to reoccur. 

no more

adv
  • No longer, not any more 

noun
  • Something that is from a certain point onwards forbidden, or non-existent 

adj
  • Dead. 

  • Not any more, no further. 

intj
  • Stop it! Don't continue! 

How often have the words never again and no more occurred in a corpus of books? (source: Google Ngram Viewer )