An idea I have for a mastery. Piercing Light.

Piercing Light : You deal 10% extra damage to shielded targets.

I'd put this at the end of the Cunning tree, since Windspeakers is only used by supports and Thunderlords used by mages and assassins and stormraiders...snickers...well lets just say that it's not as popular. Placing Piercing Light at the end of the Cunning tree would also allow it to be used more since that tree is more often maxed out than not.

Goal is to give a little bit of counter play to champions that like to spam shields, or pop shields on allies. Champions like : etc.

Was originally going to make it the unique passive to an item, but that means that I have to stack other stats on that whichs limits who can viably build it. (if you are a mage are you really going to buy an item with 60 AD just for this passive?)