tyranny vs ascendence

tyranny and ascendence both are nouns.

Word	Noun	Adjective	Verb	Adverb
tyranny	Yes	No	No	No
ascendence	Yes	No	No	No

As nouns, ascendence is a hypernym of tyranny; that is, ascendence is a word with a broader meaning than tyranny:

tyranny: dominance through threat of punishment and violence
ascendence: the state that exists when one person or group has power over another

Other hypernyms of tyranny include ascendance, ascendancy, ascendency, control, dominance.

tyranny (noun)	ascendence (noun)
a form of government in which the ruler is an absolute dictator (not restricted by a constitution or laws or opposition etc.)	the state that exists when one person or group has power over another
dominance through threat of punishment and violence