To escape from the consequences of a devastating war, the remnants of people built a huge underground city in a network of natural caves and tunnels deep under the surface of the Earth, which they called "Paradise". The blue glowing crystal "ellion" has the ability to store and accumulate energy. A strong stone wall was built around the city of Paradise to protect people from the dark creatures living in the deepest tunnels and dungeons of this underground world. Adventure, drama.