crusader vs controversialist

crusader and controversialist both are nouns.

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

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

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

Other hypernyms of crusader include disputant, eristic.

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