It's not difficult for the Blessed Land to become a Land of Calamity; all it takes is the fall of a prosperous dynasty... well, the cost is not insignificant.
As for what happened on Tianyun Mountain back then, apart from the appearance of a Phenomenon, there's really not much recorded due to how long ago it was.
Even the stories the old man tells the children around him may not be accurate versions, but one thing is certain: Tianyun Mountain did flourish, and that dynasty did exist.
"Go play now, but don't go too far." The old man reached out to pat the child's head, indicating that the story was over and he needed to attend to his own matters.
The family invited this old man, nearly at the end of his days, not only because there are ways to extend life here, but also to ask him to come out of retirement and speed up the Qingtian Continent's mastery of a new Power System.
