"Wax On, Wax Off" is the challenge associated with executing parries. These are done by pressing "Forward" when the opponent goes to strike you. The timing is picky, however you can thankfully boost this in local matches with a second controller. Simply press "LP" (Square) with the second controller and press forward promptly after and your character will flash blue and you will take no damage. Practice some to get the timing down and eventually you'll get in to a rhythm. After 75 parries, you should have your trophy.