denier vs controversialist

denier and controversialist both are nouns.

Word	Noun	Adjective	Verb	Adverb
denier	Yes	No	No	No
controversialist	Yes	No	No	No

As nouns, controversialist is a hypernym of denier; that is, controversialist is a word with a broader meaning than denier:

denier: one who denies
controversialist: a person who disputes; who is good at or enjoys controversy

Other hypernyms of denier include disputant, eristic.

denier (noun)	controversialist (noun)
any of various former European coins of different denominations	a person who disputes; who is good at or enjoys controversy
a unit of measurement for the fineness of silk or nylon or rayon
one who denies