Acnologia aka The Dragon King is a powerful Dragon Slayer that can take the form of a Dragon at any time due to his use of Dragon Slayer Magic. Acnologia was a doctor in a hidden land before he became such a violent being. He participated in a war called the Dragon King Festival, where he killed his friend and foe, and this way he became a victor of this event. Anime cursor with Fairy Tail The Dragon King Acnologia.