champion vs guardian

champion and guardian both are nouns.

Word	Noun	Adjective	Verb	Adverb
champion	Yes	Yes	Yes	No
guardian	Yes	No	No	No

As nouns, guardian is a hypernym of champion; that is, guardian is a word with a broader meaning than champion:

Other hypernyms of champion include defender, protector, shielder.

champion (noun)	guardian (noun)
someone who fights for a cause	a person who cares for persons or property
someone who has won first place in a competition
a person who backs a politician or a team etc.
someone who is dazzlingly skilled in any field

champion (adjective)	guardian (adjective)
holding first place in a contest

champion (verb)	guardian (verb)
protect or fight for as a champion