Mysterious World

After years has passed since calamity that almost ended the entire Cardinal World, Ciel who try to optimize the multiverses found an anomaly in the corner of a certain universe.

She found a world that is not registered in akashic record nor in rimuru's memories, a world that should not exist.

Hearing about this news from Ciel, Rimuru decided to venture into this mysterious world to make a decision whether to conquer it, or let it be as it is.