Power of Fire

[kitchenfork]

So just how Rare is this Power of fire from the Blazing Elementals? I have spent 2 days killing the spawns, 10+ hours both days, and not one has dropped. None of the other powers took this long to get, maybe an hour or two at most. Or is this Power of Fire like the Power of Water and not in the listed place it says on the wiki. Any help would be wonderful, Thanks in advance.