Do you wish to make a contract?

You are a demon. A demon that, unlike other demons, cares for human life. This all started when you made a contract with Vincent Phantomhive. He brought back your long lost humanity. But when he and Rachael have a son, you vow to protect him at all costs.
(Sorry I suck at descriptions XD)

Also I started writing this when I was like 12-13 so pls excuse the not so great writing towards the start lol. I may edit it in the future