firebrand

noun2

1. •
   A torch or other burning stick with a flame at one end.

   • The crowd cheered as a firebrand was tossed onto the huge pile of wood to start the traditional homecoming bonfire.
2. •
   (figurative) An argumentative troublemaker or revolutionary; one who agitates against the status quo.

   • The member of the college's Communist League was a firebrand who would launch a sit-in or protest march at a moment's notice.