You fire a bolt of dark, crackling eldritch energy at your foe.

At-Will   ✦     Arcane, Implement
Standard Action      Ranged 10

Target: One creature

Attack: Charisma or Constitution vs. Reflex

Hit: 1d10 + Charisma modifier or Constitution modifier damage.
Increase damage to 2d10 + Charisma modifier or Constitution modifier at 21st level.

Special: At 1st level, you determine whether you use Charisma or Constitution to attack with this power. Once you make that choice, you can't change it later.
    This power counts as a ranged basic attack. When a power allows you to make a ranged basic attack, you can use this power.

Update (8/11/2011)
Updated in Class Compendium.

Published in Player's Handbook, page(s) 132, Class Compendium.