The vengeance that you instill in each shot tears into your foes and lowers their defenses.

Encounter   ✦     Primal, Weapon
Standard Action      Area burst 2 within weapon range

Target: Each creature in the burst

Attack: Wisdom vs. Reflex

Hit: 1[W] + Wisdom modifier damage, and the target takes a -2 penalty to AC and Fortitude until the end of your next turn.

Published in Player's Handbook 3, page(s) 131.