Diablo III: Reaper of Souls

From what I've read, Jade Harvester cuts up to 30 seconds off the current remaining duration. Creeping Death makes the 8s duration go up to 5 minutes, and the 16s duration up to 10 minutes for Locust Swarm I believe. When you use Soul Harvest, it cuts 30 seconds from this duration and does that damage instantly. Quetzalcoatl doubles the damage per tick too, so that doubles the damage when you Soul Harvest too.