I've had a tiny spark of an idea smoldering in the back of my mind of an innocent cursed to become the demon. To restore him/herself, this demon must retrieve a piece of soul which was stolen and stored away in the church by the hateful priest. However, being a demon, this innocent is unable to enter. So, even though he/she towers over that tiny edifice, he/she is prevented from acquiring his/her rightful property and returning to normal.
That's all I got so far, but maybe it helps with the idea of turning the picture on its head.