Located in the northernmost sea of Shenzhou mainland, it is covered with fog. Dense fog makes the visibility less than one meter. The environment is bad. The sky is also covered with dark clouds. There is often a flash of lightning falling from the sky.

in the middle of the dense fog, a small island the size of a small town without any mark on the map stands an ancient and fragrant black castle. In addition to its dark appearance, the whole castle reveals a deep breath. The rapid waves constantly hit the island around, making a loud noise.

a big castle is divided into five small city buildings. The...