instigant vs troublemaker

instigant and troublemaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
instigant	Yes	No	No	No
troublemaker	Yes	No	No	No

As nouns, troublemaker is a hypernym of instigant; that is, troublemaker is a word with a broader meaning than instigant:

Other hypernyms of instigant include bad hat, mischief-maker, trouble maker, troubler.

instigant (noun)	troublemaker (noun)
someone who deliberately foments trouble	someone who deliberately stirs up trouble