Thousands of years ago, there used to be a mythological world beyond the world we now live in. That world was ruled by the priests of the good God on one side, and the priests of the evil God on the other side. They lived at war all the time. Normal civilians were forced to choose for one God, unbelievers were imprisoned and often liquidated.
In that era the God of Evil created a stone that made it possible to control and manipulate other beings. An unknown harm to the owner of the stone was that he constantly would be in frenzy, as in an eternal delirium, and so would become a servant of the Evil God.
Once each year, when the night is at its darkest, the two Gods fight for the sceptre that grants supremacy over the world for the next year. On such a day, the priests of the good God stole the stone from the God of evil while distracted by the fight with his nemesis.
They hid the stone in a cave of which they thought that nobody would find the precise location. The entrance was sealed with magic and they also placed a huge granite wall with the stone's story and immortal hazard on it, the Stone of Delusion's Saga was born.
This saga was remembered for hundred years and it became a myth, a story that was believed to be invented to frighten the people in order of keeping them pious. But some had not forgotten the source of this myth and they knew a dark force still was searching for that ancient stone. And indeed, the dark God was beaten for several years, but he still urged for his stone and awaited his moment of vengeance. He lived secluded and combined his forces, and at last, with enough power, he sent his five disciples, the Lords of Delusion, to search his stone, and he challenged the good God for a final, decisive battle.
The fury of the dark God was so deeply that he also cursed the world. If his disciples would return, and he would find the Stone of Delusion back in his grasp, then the world would perish after thirteen apocalyptic days.
From no one the world lived in an unseen fear, and everybody awaited the result of the upcoming battle of the two gods.
Then, the night called again. The time that would bring solution had come. Again the divine fury of the most destructive battle broke lose. The people waited with fear and wonder.
Finally the war ended. Both gods had used all the powers they got, and now were both too weakened to kill their opponent. They slowly and silently perished into nothingness. The world had no ruler anymore and was plunged into anarchy. But somewhere on that world still wandered the five disciples in search of the stone