Damocles, or the Emperor of Demise (as given in the anime), is the overall main antagonist of the manga Miss Kobayashi's Dragon Maid and its anime adaptation. He is a male dragon and the emperor of the Chaos Faction who had tried to indoctrinate his daughter into despising humans, to no avail.
He was voiced by Takayuki Sugō in the Japanese version of the anime, and John McCalmont in the English version of the anime.
In his human form, Damocles appears as a middle-aged man, with graying hair and a beard. He also wears a reddish-black cloak with which can be transformed into wings.
In his dragon form, he is a massive red dragon with reddish-black wings. He also sports a white mane streaking down his whole back to the end of his tail, a beard underneath his chin, mustache-like appendages, and six horns on his head.
Damocles is a callous and stern figure who greatly despises humans, viewing them as inferior due to their short lifespans, as well as evil. Despite his hatred for humanity, he, unlike the other Chaos Dragons, respects the rules that prohibit intermingling with the human realm, lest that would bring the war between the Harmony Dragons and Chaos Dragons to the Earth. Even though he holds Tohru's decision to stay on Earth with Kobayashi with contempt, it's made clear that he truly cares for her, and only wants for her to be safe.
Damocles arrives to Earth to demand Tohru to return to the Other World. He claims that the normal human life she desires is impossible, and brings up Kobayashi's mortality to further convince her to return. He also states that her presence in the human realm could lead to dragons being ousted. When Kobayashi mocks him, he tries to attack her in violation of the non-interference laws. Luckily, Tohru fights back, and she intimidates him into returning to the Other World.
Whilst struggling with coming to terms with Kobayashi's limited lifespan, the Emperor of Demise seizes Torhu, and forcefully takes her back into the Other World. Some days later, Tohru returns to the human world in defiance. The two began to have a heated argument, in which the Emperor of Demise angrily attacks Kobayashi when she tried to intervene, destroying her glasses. He then threatens to put her towards the brink of death if she didn't choose her words wisely. Kobayashi's reassurance gives Tohru enough resolve to take on her father. Her father opens a portal to an isolated area, wherein they proceed to battle each other in their dragon forms. Yet again, the battle between the two dragons is interrupted. Kanna and Kobayashi beg for the two to absolve their problems with a compromise. Even though he was vehemently against Tohru's choice for a mate, he respected her decisions, and returned to the Other World, no strings attached.