Killing the enemies to raise the platform?
I kept using L1 + X throughout the entire challenge and rolling away whenever you feel you are in danger or close to the edge.
L1 + X lifts the enemies up into the air so you can deal damage whilst being semi-protected away from everything else and bounces them back down again (hopefully off the edge).
When you see the goal, you could activate Rage of the Gods to make the last few seconds easier to bare!
Just try to stay in the middle of the platform to minimise the risk of being chucked off.
GRRRRRRRRRRRRRRRRRR those who have tried/done it will know what I'm on about. Just can't seem to do it, and the sad thing is it seems to be more about luck than skill .
As already suggested,use L1+X, and try to stay in the middle of the platform, but also use the right stick to evade attacks and as you are coming out of the roll press x(i think) the perform an attack,this attack will knock enemies off their feet giving a vital second the recover position.
I was really struggling with this challenge until I started using this tactic, then it took me 3 go's to get to the top.