mysterious vs mystifying

mysterious and mystifying both are adjectives.

Word	Noun	Adjective	Verb	Adverb
mysterious	No	Yes	No	No
mystifying	No	Yes	No	No

As adjectives, mysterious and mystifying are synonyms defined as:

Other synonyms of mysterious include cryptic, cryptical, deep, inscrutable.

mysterious (adjective)	mystifying (adjective)
having an import not apparent to the senses nor obvious to the intelligence; beyond ordinary understanding	of an obscure nature
of an obscure nature