meliorist vs controversialist

meliorist and controversialist both are nouns.

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

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

meliorist: a disputant who advocates reform
controversialist: a person who disputes; who is good at or enjoys controversy

Other hypernyms of meliorist include disputant, eristic.

meliorist (noun)	controversialist (noun)
a disputant who advocates reform	a person who disputes; who is good at or enjoys controversy