Cyclor
From Tardis Wiki, the free Doctor Who reference
The Cyclors were a race who raised the Overcast from savages to being a peaceful race. For twelve hundred years the Overcast prospered due to their help. During the Last Great Time War the War Doctor meddled with time, turning the Cyclors into the Malignant, who wiped out over fifty generations of the Overcast. (COMIC: The Then and the Now)