In the beginning of life there existed the zodiac, powerful beings that could decide fate when altogether. Soon they wished to have this power all to themselves,to decide what happens alone ,they called it the power of the celestial king and a war broke out between them ,speices ended by their battles till an agreement was made,to reincarnate , the last one standing becomes the ruler of the zodiac and it would happen again every after 100 years. This was the dawn of the war for the celestial throne.