egomania vs passion

egomania and passion both are nouns.

Word	Noun	Adjective	Verb	Adverb
egomania	Yes	No	No	No
passion	Yes	No	No	No

As nouns, passion is a hypernym of egomania; that is, passion is a word with a broader meaning than egomania:

egomania: an intense and irresistible love for yourself and concern for your own needs
passion: an irrational but irresistible motive for a belief or action

Other hypernyms of egomania include cacoethes, mania.

egomania (noun)	passion (noun)
an intense and irresistible love for yourself and concern for your own needs	the trait of being intensely emotional
	any object of warm affection or devotion
	a strong feeling or emotion
	a feeling of strong sexual desire
	an irrational but irresistible motive for a belief or action
	something that is desired intensely