annihilator vs undoer

annihilator and undoer both are nouns.

Word	Noun	Adjective	Verb	Adverb
annihilator	Yes	No	No	No
undoer	Yes	No	No	No

As nouns, undoer is a hypernym of annihilator; that is, undoer is a word with a broader meaning than annihilator:

Other hypernyms of annihilator include destroyer, ruiner, uprooter, waster.

annihilator (noun)	undoer (noun)
a total destroyer	a person who destroys or ruins or lays waste to
	a person who unfastens or unwraps or opens
	a seducer who ruins a woman