Open! Gate of the Demon! {A Nalu Fanfiction}

Lucy receives a silver key as a reward on a job that she and Happy went on.

But this isn't an ordinary silver key. It's the gate of the demon. It's said to be one of the few silver keys that actually have fighting power.

But that's not all. It's also as rare as the gold keys; there's only one.

So what makes this key so special?

~This is my first Nalu fanfic so I hope u like it!~