Your strike puts your opponent off guard, allowing your allies to better exploit the enemy's openings.

At-Will   ✦     Martial, Weapon
Standard Action      Melee weapon

Target: One creature

Attack: Strength vs. Will

Hit: 1[W] damage. Until the start of your next turn, the next ally who attacks the target and has combat advantage against it gains a +2 power bonus to the attack roll.
Level 21: 2[W] damage.

Update (4/13/2010)
In the Hit entry, replace “any” with “the next.” Also, replace “a bonus to the attack roll equal to 1 + your Wisdom or Charisma modifier instead of the normal +2 bonus” with “a +2 power bonus to the attack roll.”

Published in Martial Power 2, page(s) 83.