In the German city of Kreuznacht, eight ordinary people suddenly become Soulbound to legendary beings known as Eidolons. Bound by an ancient ritual called the Astral Rite, they must fight until only one remains. When an Eidolon falls, its power transfers to another Soulbound. Whoever gathers all the power—or survives until the end of the ritual—earns a single wish capable of changing their fate.