"There are more than seven Old Gods and not all of them are from of the Tevinter Imperium.
Legends tell of The Black City itself was cast out of the Fade by The Maker once it became tainted with sin and sank beneath the oceans. The City, named Ry'leh is now the dwelling place of the sleeping Old God, Cthulhu the Archdemon who will awake when the stars are right.
The final Blight will come from the seas not the Deep Roads and even the so called Gray Wardens cannot breath underwater.
Maker help you all."
-Statement made by the apostate Alhazred, "The Mad Antivan" before his execution. 901: Dragon.
It all comes down to blood and choice.