prepotency vs ascendancy

prepotency and ascendancy both are nouns.

Word	Noun	Adjective	Verb	Adverb
prepotency	Yes	No	No	No
ascendancy	Yes	No	No	No

As nouns, ascendancy is a hypernym of prepotency; that is, ascendancy is a word with a broader meaning than prepotency:

prepotency: the state of being predominant over others
ascendancy: the state that exists when one person or group has power over another

Other hypernyms of prepotency include ascendance, ascendence, ascendency, control, dominance.

prepotency (noun)	ascendancy (noun)
the state of being predominant over others	the state that exists when one person or group has power over another