Shredding Vibrato has a requirement of "You may only play this attack if you have discarded 2 attacks from your card pool."
Does this mean I have to use an effect that says "Discard" or can I clear my card pool in other ways?
Prime examples.. Raphael can add attacks to his momentum with his 2nd ability. And Flurry of Thrusts does it as well. Can these be used to fulfill Vibratos conditions?