Okay, so. After getting on the side wall and past the damage barrier (with wind waker), I wind waker dived off the edge and then after falling for a while I canceled it and took out my leaf and I got past the barrier.
so, I got past the barrier...
the problem was that I was miles down under the ground...
but I recently found out that you can use the wind waker with 0 hearts if you mash it after knockback. So if I can lose my last heart with knockback and fly back into an un-exploded bomb, and ge out the wind waker, I could possibly pull out the wind waker and dive off the edge with 0 hearts. After I have fell for a while I can cancel the wind waker and start hovering up to ganon's castle entrance.
so if you want to try then please, do.
That's actually exactly the idea Parax had.
You can't stay inside the damage barrier and Wind Waker dive at the same time, let alone while dead. If you find a way to do it, kudos to you. I can't test anything, computer is burning up again.
Edit:
I've also got a wind waker dive off the edge with 0 hearts (so I can start hover streight after)
I need to read better.