The barbarian unleashes a terrifying howl as a standard action. All shaken enemies within 30 feet must make a Will save (DC equal to 10 + 1/2 the barbarian's level + the barbarian's Strength modifier) or be panicked for 1d4+1 rounds. Once an enemy has made a save versus terrifying howl (successful or not), it is immune to this power for 24 hours. A barbarian must have the intimidating glare rage power to select this rage power. A barbarian must be at least 8th level before selecting this power.