Sold My Soul *editing*

Ivory Delphine is not any regular 18 year old girl. She's a soulless body that's wandered the Earth for over 200 years, doing the will of her master, Lucifer.
Who just so happens to be the devil.
But one day she's sent to oversee the death of a man when a boy named Westley sees her - when he's not supposed to be able to. Normally she's supposed to report these kinds of people to her ruler, but she refuses to condemn anyone to the fate she was doomed to many years ago.
But what happens when this boy insists on finding out more about her?
And what happens when she finds herself falling for this innocent, human being?
What happens when the devil becomes frightfully jealous?