Tide of Blood is an encounter power available to the Barbarian class at level 7.[PH2:54]
Tide of Blood
Barbarian Attack 7
Melee weapon
Target: one creature
Attack: Strength vs AC
Hit: 2[W] + Strength modifier damage. The attack deals 1 extra damage for each enemy adjacent to you.
Rageblood Vigor: The attack deals 1 extra damage for each enemy within a number of squares equal to your Constitution modifier.