Sounds like a fun character to play. The next thing to concentrate on is what does this entity want with her? Why save her? Is it actually really weak and needed a body? Are these nightmares from people from her past lineage who are fighting to get her back? If so can we meet one of these characters in the campaign?
All things to ask your DM about. The story will just flow from there and I guarantee they will appreciate it. - A forever DM