mystifier vs problem

mystifier and problem both are nouns.

Word	Noun	Adjective	Verb	Adverb
mystifier	Yes	No	No	No
problem	Yes	No	No	No

As nouns, problem is a hypernym of mystifier; that is, problem is a word with a broader meaning than mystifier:

mystifier: a particularly baffling problem that is said to have a correct solution
problem: a question raised for consideration or solution

mystifier (noun)	problem (noun)
a particularly baffling problem that is said to have a correct solution	a source of difficulty
	a question raised for consideration or solution
	a state of difficulty that needs to be resolved