Demon Princess (Nalu Fanfic)

Lucy Heartfilia, a 17 years old girl and a Celestial Mage of Fairy Tail, has been a daughter of a demon and a human. One day, a female demon named Shiara went to Fairy Tail to pick up Lucy and trained her to be the next Demon Princess or atlist protect herself. She was gone for 3 years, and since she ever came back, a...