how to beat the Ghost crystal? (Tales of Berseria)

I am writing to say it should be on a level easy to take, and however do not write as it is possible to change the level? what is the armor reflect damage need to wear, but do not specifically write for the armor. I have let the reflection of the 10% reflect damage, but only when you get damage which will come to zero damage. that is, the probability is negligible.
and they write about what that armor that you might think that all and any type of damage and it always will be reflected, if not the entire? what kind of armor are, it's in the bonus abilities from the armor that randomly appear, or is it in the main features of armor this enchantment. and where such armor to take?