As I said, I became this draugr. But there is a greater purpose.

My life had to be extended, so I used my knowledge of the black arts, and I turned myself into the creature you see before you. A Draugr. Eater of Flesh. But my life was infinite. I could keep the barrier intact so that my people might survive. And now you appear. To kill me, perhaps? You may have the power, but perhaps you have a greater purpose here.