mastery vs ascendance

mastery and ascendance both are nouns.

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

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

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

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

mastery (noun)	ascendance (noun)
the act of mastering or subordinating someone	the state that exists when one person or group has power over another
great skillfulness and knowledge of some subject or activity
power to dominate or defeat