Fairy Tail x Reader - Acnologia's dragon slayer

Same magic, different creatures. He's hundreds of years old and she's barely 19. He's the darkness and she's the light. The dark dragon, Acnologia, has one weakness, one fear, and one dragon slayer. The wizard, (Y/N), has one dragon, one guild, and one regret. However, their lives are forever intertwined. WARNING...