Irene’s reference is the Novus Aether from the Aiyoku no Eustia manga series Aiyoku no Eustia (穢翼のユースティア, "Eustia of the Tarnished Wings") is a Japanese adult visual novel developed by August and released on April 28, 2011. Aiyoku no Eustia is August's eighth game, preceded by Fortune Arterial and Yoake Mae yori Ruriiro na: Moonlight Cradle. It was planned to be released on March 25, but the schedule was changed due to the Great East Japan earthquake. After the surface of the world succumbed to chaos centuries ago, the city of Novus Aether is kept afloat in the sky solely by the continual prayers offered by the Saint. Years ago, when the Saint’s prayer was interrupted, an incident known as the “Gran Forte” occurred, causing a portion of the land to fall and split the lower city into two, separated by a cliff. Countless lives and property were lost or irreversibly affected in what would be known as the greatest disaster in the city’s history. In time, the lowest layer, known as the “Prison”, became the home to people who lost much of their former lives during the “Gran Forte”. The current Saint, Irene the 29th is gifted with a way with words and incredible strength of faith. Originally a homeless girl, she met Lavria, who would become a sister figure to her, on the streets. The Church would eventually take them both under its wing; she was selected to be the new Saint, to offer constant prayer on behalf of everyone in Novus Aether, after Irene the 28th was executed for interrupting her prayer and causing the "Gran Forte". The developers used Greek mythology when they tried to portray the name of the city and religion. It was based on Aether. In Greek mythology, Aether, Aither, or Ether is the personification of the bright upper sky. According to Hesiod, he was the son of Erebus (Darkness) and Nyx (Night), and the brother of Hemera (Day). For the ancient Greeks, the word aether, referred to the upper atmosphere, a material element of the cosmos.