Antagonist adjectives are listed in this post. Each word below can often be found in front of the noun antagonist in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing ANTAGONIST.
able, adrenergic, bitter, chief, competitive, dangerous, direct
dopamine, fair, fierce, first, former, formidable, great
late, main, mean, mighty, natural, new, old
only, opiate, opioid, political, powerful, principal, real
redoubtable, selective, single, specific, successful, terrible, victorious
wily, worthy, young
Hope this word list had the adjective used with antagonist you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.