Fairy Tail: The Celestial Priestess, Keeper of the Crystal Key (a Nalu Fanfiction)

Not much is known about Celestial Wizards or their powers. For Lucy Heartfilia, a celestial wizard at the infamous guild Fairy Tail, any bit if information on the rare magic is a great welcome. So when two strangers arrive at Magnolia claiming to know the great secrets of celestial magic Lucy is more than a little intrigued. But before she can accept their offer to train her she is taken from her home in the middle of the night by an unknown foe.

Waking up in a strange new land Lucy learns the real reason she was taken, and it's not good. She has been chosen to be the next Celestial Priestess and be the Keeper of the Crystal Key. It's a great responsibility and with all the power that comes with the Key there is a great cost to be paid. But Lucy knows what is at stake if she fails and, like a true Fairy Tail wizard, accepts the challenge.

With the last Celestial Priestess a great evil named Erebus was sealed away in the spirit world over seven hundred years ago. But someone is planning on releasing him back into the world and now only Lucy, along with her friends from Fairy Tail, can stop it.

Faced with the difficult task of learning her new powers, understanding which side is really in the wrong, and as feelings begin to develop Lucy must decide if her future is really worth fighting for if it means risking everything else.