Castiel x Demon reader

I am know as Mortem which is latin for death. I was born a demon loyal to Lucifer. At least that's what I was thought to be. I was then introduced to the Winchesters who had known me since I was two. In human years that is. Once they found out of my demon side they did the normal procedure and later found a hidden trust and love for me. I was then seen as their sister and ally and fought hard and well when Dean was drug to hell. Now I have been told of the angel Castiel dragging Dean from hell from the whispers of the demons minds. I am awaiting the arrival of this angel to learn more of him and see if he may be trusted.