Circle of Battle is an utility power available to the Barbarian class at level 10.[HotF:49]
Circle of Battle
Barbarian Utility 10
Target: One enemy subject to your defender aura
Effect: As a free action, each of your allies adjacent to the target can shift up to 2 squares to a square not adjacent to the target. Additionally, until the start of your next turn, when you hit the target is an opportunity attack or your vengeful guardian attack, you immobilize it until the end of its turn.