ruiner vs undoer

ruiner and undoer both are nouns.

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

As nouns, ruiner and undoer are synonyms defined as:

Other synonyms of ruiner include destroyer, uprooter, waster.

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