cataclysm vs misfortune

cataclysm and misfortune both are nouns.

Word	Noun	Adjective	Verb	Adverb
cataclysm	Yes	No	No	No
misfortune	Yes	No	No	No

As nouns, misfortune is a hypernym of cataclysm; that is, misfortune is a word with a broader meaning than cataclysm:

cataclysm: an event resulting in great loss and misfortune
misfortune: unnecessary and unforeseen trouble resulting from an unfortunate event

Other hypernyms of cataclysm include bad luck.

cataclysm (noun)	misfortune (noun)
an event resulting in great loss and misfortune	unnecessary and unforeseen trouble resulting from an unfortunate event
a sudden violent change in the earth's surface	an unfortunate state resulting from unfavorable outcomes