In a world with swords and magic there exist dungeons and levels. Two Gods have a child. The Goddess of earth was jealous of the Goddess of the sun for having a child with the God of the moon. The Goddess of earth stole the child away from them a trapped the child in a dungeon hidden form the light of day. The child being a god was born with immortality and could not die of old age and hadn't a need for food or water. The child had nothing to do but train his mana as he didn't know anything about the world he was in. He was stuck in that prison for 250 years.