despot, absolute ruler, inquisitor; see dictator.
"tyrant." YourDictionary, n.d. Web. 17 August 2018. <http://thesaurus.yourdictionary.com/tyrant>.
tyrant. (n.d.). Retrieved August 17th, 2018, from http://thesaurus.yourdictionary.com/tyrant
An absolute ruler, especially one who is harsh and oppressive:
One who imposes or favors absolute obedience to authority: