The pain your enemy suffers from your attack is also felt by its allies.

Encounter   ✦     Arcane, Implement, Necrotic
Standard Action      Ranged 10

Target: One creature

Attack: Charisma vs. Reflex

Hit: 2d8 + Charisma modifier necrotic damage. Each enemy within 2 squares of the target takes necrotic damage equal to your Intelligence modifier.

Published in Arcane Power, page(s) 88.