Vanguard Bulwark

Prerequisite(s): 7th level dauntless defender
Benefit(s): While you are wielding a tower shield with both hands, you can spend an immediate action (in response to a spell/ability/etc. with a cone area or line area) in order to prevent the effect of that spell/ability/etc. from entering or passing through your square; every being that is located either in your square or in a square that is behind yours remains unaffected by that spell/ability/etc.