It seems to refresh itself when it reaches zero. If I then cast a new Nether Tempest on the target there'll be two DoTs on the target (according to the tracker that is), and when there's two DoTs the first "refreshing" one will disappear once it reaches zero and the new second one will start to refresh instead (by the looks of it).
It seems to refresh itself when it reaches zero. If I then cast a new Nether Tempest on the target there'll be two DoTs on the target (according to the tracker that is), and when there's two DoTs the first "refreshing" one will disappear once it reaches zero and the new second one will start to refresh instead (by the looks of it).