True. Cruel waveshining is a very slow damaging tactic not particularly worth learning. for instatnce, a drillshine>drillsine (start+one iteration of the drillshine infinite will rack up as much damage as 6-8 shines of cruel waveshining, works on more of the cast, and is similar in difficulty. That being said, i find it easiest to do by shining them, doing another shine in the same direction, and then shining them in the reverse direction. This is so you're moving while shining them so you have momentum when you waveshine and it's easier to get behind someone. Note the cruel waveshine only works on link, peach, and zelda (not sheik). I only know how to do this because i just like learning every tech trick i can because i'm like that. I don't ever use this technique.
