You'll only have forty seconds this time to defeat Demyx. You will want
to do the same strategy as before, only this time you'll need to speed
things up a bit. Get into Valor Form and remember to use the Wild Dance.
Forty seconds is not a whole lot of time.
If you have Donald's Comet available, then use it, because it will help
you defeat Demyx. Once you have defeat all of the Demyx Forms, you will
notice the timer has stopped and Demyx is vulnerable. Quickly switch to
Valor Form and start attacking Demyx with everything you've got.
Similar to Axel, Demyx uses abilities focused on the elements, so watch
out for the bubbles and pillars of water. How do you avoid these? Great
reflexes, Donald's Comet, Limits, Drives, and Reaction Commands.
Here's where you need to be quicker on the controller. Eventually he'll
cast out ten Demyx Forms which must be defeated in ten seconds. Use the
Wild Dance to quickly take care of them. After Demyx runs low on health,
staying near him is an accident waiting to happen.
If you get too close to him, pillars of water will start to form. When
you're too far away, he'll cast bubble at you, and if you successfully
pass his pillars of water, he'll start beating the crap out of you, so
start attacking from a distance, or wait for Donald's Comet command to
interrupt his rampage. If you don't have Comet, wait until Demyx casts
out his Demyx Forms, defeat them, and then attack Demyx.