Engine of Ceaseless Progress

periodically, the Heart of Azeroth empowers you with variable Haste, Mastery, or Critical Strike. After reaching variable stacks of either Haste, Mastery, or Critical Strike, the Heart of Azeroth temporarily overcharges, doubling the effects of Engine of Ceaseless Progress for a variable duration, after which the stacks are removed. · · When you gain a stack of one of the Engine buffs, you have a a variable amount chance to generate a second stack.