Antagonist rhymes with:
protagonist, protagonist, organist, protagonist, abolitionist, accompanist, arsonist, botanist, calvinist, chauvinist, communist, conservationist, contortionist, determinist, exhibitionist, expressionist, feminist, illusionist, impressionist, isolationist, jansenist, neoplatonist, obstructionist, organist, perfectionist, platonist, protagonist, unionist