Who is she? Upper moon 0... (Douma x F! Reader)

Over a thousand years ago, (Y/n) was a human and lived with her family in a village. (Y/n) had been born with a fatal disease that had no cure so there was no hope in a good life for her. When (Y/n) turned 16 she was put in an arranged marriage and she was upset from this. Thinking that her life will be bitter and...