Thousands of years ago, in order to check and balance the Emperor of Heaven, the immortal world established three major immortal capitals to assist the Emperor of Heaven.
It's called auxiliary, but it's actually a check and balance.
At that time, they had just experienced two battles between immortals and demons. The immortal world was severely damaged, and other races were also ready to take action. The demon race was the first to bear the brunt.
At that time, the three great immortals came to the lower realm to meet with the demon king, and then they decided on the marriage between Xuan Ying, the eldest son of the Emperor of Heaven, and Qi Wu, the princess of the demon tribe.
However, a hundred years ago, there was news from the demon clan that the princess of the demon clan was missing.
Intention: Everything is fate, but never leave peace and true love in the world!