Blood Wrath is an encounter power available to the Barbarian class at level 27.[PH2:60]
Blood Wrath
Barbarian Attack 27
Melee weapon
Target: one creature
Attack: Strength vs AC. You gain a +2 bonus to the attack roll if the target is bloodied.
Hit: 5[W] + Strength modifier damage, and you gain a +2 bonus to attack rolls until the end of your next turn.
Rageblood Vigor: The bonus to attack rolls equals you Constitution modifier.