50% from piercing

I have a trouble finding an ability that will reduce piercing attacks by 50%, any ideas?
(No I cannot use defend because it has turn on/off and I need a passive one)

Elune's grace.

What is this?
Data - Deflect Damage Taken (Piercing) - 1.00

And why is it set to one?

It is how much damage you take when an attack is deflected. So in this case you take full damage and none is deflected, although there is a 0% chance to deflect anyways. On Defend, you take no damage and all of it is reflected, because it is set to 0 (and then there is a 30% chance to deflect, as set in the Chance to Deflect field).

why dont you make an armor type that take only 50%
from piercing... Be creative :)

Need more help???