After the Spellplague, a divine caster with the Vengeance domain would become more intimidating. In addition, when they used certain offensive powers and hit a target enemy, they suffered damage if they subsequently struck the caster or their ally. These powers were astral seal (for clerics), avenging light (for invokers), holy strike (for paladins), and radiant vengeance (for avengers).
After the Spellplague, the divine caster could channel divinity to use small vengeance. If they were badly wounded, they could channel their deity's essence and return the pain to their enemy, injuring them.