You guessed that if Bai He arrived too late, there were roughly two things he might do.
One was that he would grow too impatient to keep waiting, directly increase the fate of the other nine, make the other nine ascend to immortality at breakneck speed, then destroy all of them together.
The second was that, like certain classic villains who failed to pull out the weeds by the roots, he would destroy the entire Yuan Tian Realm, leave behind only those Ten Children of Destiny, and kindly move them into the universe.
Before leaving, he would toss out a line: "Angry? Grief-stricken? I'll wait for you to come kill me. Once you have all become immortals, you may go to the place of **, where I shall await your revenge!"
He might also repeat the old storyline from before—kill the Child of Destiny who had ascended first, make the others think he had provoked Calamity Beasts while outside, then establish the Calamity Force Field anew...
There were many possibilities. You did not wish to experience that unknown risk, so you directly retraced the road you had already traveled.
You arrived in a relatively remote Yuan Tian Domain and looked toward a valley, where one person stood—Ge Hu.
"A brand-new NPC, a character who had never appeared before."
He was someone you had selected from a certain Lower Realm more than a hundred years ago: a corrupt official who committed every evil under heaven and was about to be executed.
There was nothing special about him. You had chosen him only because you happened to see him. Consider him lucky; you had decided to grant him a great opportunity.
Back then, Ge Hu had preyed upon the common people, murdered men and seized their wives and daughters. Later, he went