egoist vs unpleasant person

egoist and unpleasant person both are nouns.

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

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

Other hypernyms of egoist include disagreeable person.

egoist (noun)	unpleasant person (noun)
a self-centered person with little regard for others	a person who is not pleasant or agreeable
a conceited and self-centered person