mastership vs skill

mastership and skill both are nouns.

Word	Noun	Adjective	Verb	Adverb
mastership	Yes	No	No	No
skill	Yes	No	No	No

As nouns, skill is a hypernym of mastership; that is, skill is a word with a broader meaning than mastership:

Other hypernyms of mastership include accomplishment, acquirement, acquisition, attainment.

mastership (noun)	skill (noun)
the position of master	ability to produce solutions in some problem domain
the skill of a master	an ability that has been acquired by training