Spending 10% life grants you a stack of Blood Cascade up to 50 times. Each stack of Blood Cascade increases the damage of life-spending attacks by 200% and also increases the life you lose by 10%. Using a skill to heal will consume a stack and heal for an additional 300%.

Healing from skills consumes one stack regardless of how many targets are hit

Command Skeletons: Dark Mending and Land of the Dead: Land of Plenty no longer consume stacks or receive increased healing