Primal War Band Rage is a daily power available to the Barbarian class at level 19.[PrP:20]
Primal War Band Rage
Barbarian Attack 19
The spirits of an ancient war band spiral around you, distracting your foes.
Melee weapon
Target: One creature
Attack: Strength vs AC
Hit: 5[W] + Strength modifier damage.
Miss: half damage.
Effect: You enter the rage of the primal war band. Until the rage ends, each enemy within 5 squares of you grants combat advantage to you.