Wrathful Judgement is a 19th level cleric Daily power that was introduced in Heroes of the Fallen Lands.
Wrathful Judgment
Cleric Attack 19
You place a baleful mark of retribution upon your enemy, dooming it to feel the pain it inflicts on others.
Melee 1
Target: One creature
Effect: Until the end of the encounter, whenever the target damages one of your allies, you can use an immediate reaction to deal half that damage to the target. This damage ignores that target's immunities and resistances.