WoWDB

While inside the Maw or Torghast, your spells and abilities have a chance to drain a Soul Fragment from your target, granting you 0 Primary stat for 30 sec and stacking up to 15 times.

When you reach 15 stacks, unleash Chaos Bane, dealing 0 Shadow damage split between nearby enemies and granting you 0 Primary stat for 15 sec.