On the second half..some of the crystals are on the lower section....a location that the strategy guide doesn't mention them....you have to really explore the lower section..which curls around the Destroyer's arm or something....but they are there...I was angry because I thought their might have been a glitch in the game....but I found them.

I can see that there's a crystal up ahead and I can't get at it because every time I try and get close it just lnocks me down again

actually there is a wall to the left of the air streem and an open ing where you take off and you can go on the out side of the wall and around

Anyways you have to look below the Destroyer's armpit or something. When your on his back..you turn around to see the Blue Spirit crystals across from you...shatter those then go down towards the water. You really have to circle around that section to find those annoying crystals...then when you have you go back up to the Destroyer's back where you will fight some baddies then destroy the last one.