In your single-minded devotion to destroying your chosen foe, you strike at that foe and form a psychic bond with it that causes it to suffer if its allies attack you.

Daily   ✦     Divine, Psychic, Weapon
Standard Action      Melee weapon

Target: One creature

Attack: Wisdom vs. Will

Hit: 2[W] + Wisdom modifier psychic damage.

Miss: Half damage.

Effect: Until the end of the encounter or until you attack anyone other than the target, the target takes 5 psychic damage whenever another enemy hits you.

Published in Player's Handbook 2, page(s) 40.