dominion vs ascendency

dominion and ascendency both are nouns.

Word	Noun	Adjective	Verb	Adverb
dominion	Yes	No	No	No
ascendency	Yes	No	No	No

As nouns, ascendency is a hypernym of dominion; that is, ascendency is a word with a broader meaning than dominion:

dominion: dominance or power through legal authority
ascendency: the state that exists when one person or group has power over another

Other hypernyms of dominion include ascendance, ascendancy, ascendence, control, dominance.

dominion (noun)	ascendency (noun)
a region marked off for administrative or other purposes	the state that exists when one person or group has power over another
dominance or power through legal authority