Thousands of years ago in the great nation of Hepeng, a violent lightning storm took over the skies striking the unsuspecting citizens. Fortune tellers all over the land had long predicted the great storm, a showcase by the gods expressing their displeasure with their goddess of Hepeng, Guāng. Like every other god, she had her own nation which in her case was Hepeng. But she believed in free will, allowing her people to go astray all in the name of freedom going against what heavens intended.
The lightning storm brought about giants, trolls and dragons that ravaged Hepeng's cities with the aim of exterminating all mankind. The gods promised to free Hepeng's people from their misery if Guāng would follow their rules but she was relentless and sort another solution. Bestowing a little of her power to the chief of Hexie province, Wu Zhu, a man with a brave heart, she was able to regain some form of control.
Seeing how useful humans could be, she gave his two sons, Wu Chun and Wu Jiaohua some of her power so they could assist their father in regaining Hepeng from the ruthless creatures and it was a success but it came at a cost. Guāng had promised the chief that she would make him the emperor but as she granted his wish, a troublesome future flashed before her eyes.
If Wu Jiaohua was to inherit the throne as the first son, a ruthless inexplicable evil would be unleashed. She witnessed him bringing back all the evil beings they had driven out of their borders and using them not to only wreak havoc to her nation but invade other nations. In desperation, she begged the now King, Wu Zhu to convince his son to give the thrown to his younger brother Wu Chu.
He might have been stubborn but Wu Jiaohua was surprisingly an obedient child, he knew his father had his reasons so he agreed with him under one condition that his son would be next in line for the throne. To ensure his bloodline wasn't cheated out of what rightfully belonged to them, he insisted the three of them make an oath in the presence of Guāng herself.
Guāng prepared an amulet which would bind the vow and before her they made an oath that Wu Jiaoshen's son would be named crown prince. Though they were family by blood, they didn't trust each other and it wasn't without reason. Wu Zhu silently altered the oath, vowing that his first son's bloodline could only inherit the throne in the third generation while Wu Jiaoshen vowed if his brother was to break the terms of the agreement and doesn't give back the throne to his bloodline, whoever was appointed as the crown prince would die.
Fully aware of the breach in contract by both parties, she created her own failsafe. The amulet in which the oath was stored, would break into three pieces and kept in different locations. When the time comes for the oath to take effect, Wu Chu's bloodline could always find all the pieces and alter the oath. Though her fall back-up plan was reasonable, she had to birth a being that could sense the location of all three pieces as she herself could not directly intervene.