tyranny vs ascendance

tyranny and ascendance both are nouns.

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

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

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

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

tyranny (noun)	ascendance (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