demon vs unpleasant person

demon and unpleasant person both are nouns.

Word	Noun	Adjective	Verb	Adverb
demon	Yes	No	No	No
unpleasant person	Yes	No	No	No

As nouns, unpleasant person is a hypernym of demon; that is, unpleasant person is a word with a broader meaning than demon:

Other hypernyms of demon include disagreeable person.

demon (noun)	unpleasant person (noun)
an evil supernatural being	a person who is not pleasant or agreeable
a cruel wicked and inhuman person
someone extremely diligent or skillful