incensor
/ɪnsɛnˈsɔr, ɪnˈsɛn.sɔr/Definitions
1. noun
A person who incites or encourages others to take violent or destructive action, especially against a government or institution.
“The authorities arrested the incensor who had been spreading subversive propaganda online.”
2. verb
To incite or encourage others to take violent or destructive action, especially against a government or institution.
“The government accused the activist of incensing the mob to riot in the streets.”