domination vs ascendency

domination and ascendency both are nouns.

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

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

domination: power to dominate or defeat
ascendency: the state that exists when one person or group has power over another

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

domination (noun)	ascendency (noun)
social control by dominating	the state that exists when one person or group has power over another
power to dominate or defeat