Astralbringer: Shaded Arkarium

In the past, a world on the brink of unprecedented crisis due to an all-out war. The world's destruction was averted by the sudden appearance of a being called the "Eternity". In a world where air and soil pollution has worsened, the "Eternity" develops and builds a huge isolation platform called the "Arkarium" in order to escape from the critical situation in which they are living. Under the control of the "Eternity," people are living happily in the "Arkarium".