| After years of endless conflict an unexpected event - the Ultima Ruina, puts an end to the Limbo War changing the shape of world forever. As result, half of Heaven territory becomes a lifeless wasteland known as Purgatory and strange beings called Despairs appear, born from humanity sins.
In the following years, Rain, a survivor of the Ultima Ruina, is invited to the join the new Nightmare Squad, a special team created in order to find the ones responsible for the Ultima Ruina and the secret weapons that disappeared with them.
However, nothing about their mission is what it seems, as they start to learn about the mysterious Nightmare Project.
New chapter every month.