Torment in a Jar's ramping damage is increased based off of number of stacks.
Your attacks have a chance to unleash a remnant of Azshara's torment, dealing 0.3387 × SP shadow damage to all nearby enemies and granting you Unleashed Agony, increasing the damage of this effect by 100%. Upon reaching 12 stacks of Unleashed Agony, they are consumed to deal 19.3825 × SP Shadow damage to all nearby enemies.