When the protagonist dies, they wake up in an alternate reality called the Evershadow, a dangerous mirror world populated by the souls of the dead and creatures called Revenants. To survive, they must conquer dungeons and absorb "Essence Shards" to grow stronger. As they rise through the ranks of the Evershadow, they realize there’s a way to return to life—but only if they defeat the current ruler of the realm.