Alone but Forever as One

Two sister, trained in the middle of the sea. No one knew about their existence until the biggest storm of the century hits. Now every dragon slayer in the land is called to form a team to try and take the two out. But when they do meet will they find it necessary to kill them? Or will they find that the two girls are the key to the mysteries that have been flying around the magical community?
What ever is found out in the end, there is no question that these two dragon slayers bring more punch and more bite than anyone has ever seen before, and no one knows what troubles or what pleasures they will bring. All anyone truly knows is that they can bring a hell of a lot of fear, to even Erza.