FIREBRAND
instigator, provoker, inciter, instigant, firebrand
(noun) someone who deliberately foments trouble; “she was the instigator of their quarrel”
brand, firebrand
(noun) a piece of wood that has been burned or is burning
Source: WordNet® 3.1
Etymology
Noun
firebrand (plural firebrands)
(figurative) An argumentative troublemaker or revolutionary; one who agitates against the current situation.
Synonyms: radical, revolutionary, troublemaker
A torch or other burning stick with a flame at one end.
Source: Wiktionary
Fire"brand`, n.
1. A piece of burning wood. L'Estrange.
2. One who inflames factions, or causes contention and mischief; an
incendiary. Bacon.
Source: Webster’s Unabridged Dictionary 1913 Edition