war criminal vs wrongdoer

war criminal and wrongdoer both are nouns.

Word	Noun	Adjective	Verb	Adverb
war criminal	Yes	No	No	No
wrongdoer	Yes	No	No	No

As nouns, wrongdoer is a hypernym of war criminal; that is, wrongdoer is a word with a broader meaning than war criminal:

war criminal: an offender who violates international law during times of war
wrongdoer: a person who transgresses moral or civil law

Other hypernyms of war criminal include offender.

war criminal (noun)	wrongdoer (noun)
an offender who violates international law during times of war	a person who transgresses moral or civil law