Romancing SaGa THE STAGE ~Roanne ga Moeru Hi~ (2017)

Every 300 years the Death Eclipse kills all newly born creatures. Men, women, and children, animals and plants, even ferocious monsters - no one can survive the devastation caused by the Eclipse. No one except a child chosen by the destiny. 600 years ago, such a child survived the Death Eclipse, only to become a demon king. During the next Eclipse, a chosen child became a holy king, and he defeated the evil demon king. Now, when the next Eclipse is nearing, nobody knows who the next fortunate survivor will become - a demon or a holy man?