Arrow of Vengeance
Ranger Attack 17
You point your bow at the villain who just wounded your friend and loose a vengeful arrow.
Ranged weapon
Trigger: A creature within range attacks your ally
Target: The attacking creature
Attack: Dexterity vs. AC, and gain a power bonus to this attack equal to your Wisdom modifier.
Hit: 2[W] + Dexterity modifier damage.
Arrow of Vengeance is an encounter power available to rangers at the 17th level.[PH:110]