Affliction - Warlock - Wrath of the Lich King

You send a ghostly soul into the target, dealing 405–473 Shadow damage and increasing all damage done by your Shadow damage-over-time effects on the target by 20% for 12 s. When the Haunt spell ends or is dispelled, the soul returns to you, healing you for 100% of the damage it did to the target.

Your Corruption and Unstable Affliction spells gain an additional 5% of your bonus spell damage, and your Drain Life, Drain Soul, Shadow Bolt, and Haunt spells have a 100% chance to reset the duration of your Corruption spell on the target.

Increases the amount drained by your Drain Life by 30% while your health is at or below 20% health, and increases the damage done by your Shadow spells by 12% when your target is at or below 35% health.