mystifier vs sudoku

mystifier and sudoku both are nouns.

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

As nouns, sudoku is a hyponym of mystifier; that is, sudoku is a word with a more specific, narrower meaning than mystifier:

mystifier: a particularly baffling problem that is said to have a correct solution
sudoku: a number puzzle in which the numbers 1 through 9 must be placed into a grid of cells so that each row or column contains only one of each number

Other hyponyms of mystifier include acrostic, word square, chess composition, chess problem.

mystifier (noun)	sudoku (noun)
a particularly baffling problem that is said to have a correct solution	a number puzzle in which the numbers 1 through 9 must be placed into a grid of cells so that each row or column contains only one of each number