Guardian of Howling Wrath is a 19th level shaman Daily attack that was introduced in the 372nd edition of Dragon (magazine).
Guardian of Howling Wrath
Shaman Attack 19
Your spirit transforms into a howling echo of death, assaults your enemies, consumes their life force, and channels it into primal power.
Melee spirit 1
Target: One creature
Attack: Wisdom vs. Will
Hit: 4d10 + Wisdom modifier necrotic damage.
Miss: Half damage.
Effect: Until the end of the encounter, when an enemy within 2 squares of your spirit companion drops to 0 hit points, you gain a +2 power bonus to attack rolls until the end of your next turn.