As your weapon clashes against your foe, a thunderclap resounds and empowers all your nearby allies.

Encounter   ✦     Arcane, Thunder, Weapon
Standard Action      Melee weapon

Target: One creature

Attack: Charisma vs. AC

Hit: 2[W] + Charisma modifier thunder damage. Each ally within 2 squares of the target gains a bonus to his or her next attack roll against that target equal to your Constitution modifier.

Special: If there are more enemies than allies within 10 squares of you, the bonus to attack rolls increases by 2. Count only active enemies and allies, not unconscious, dead, or dying creatures.

Published in Arcane Power, page(s) 21.