[The emergence of the Plague Realm came both from the Dao Source World Tree and from your side of the All Heavens universe. Since the Great Darkness Calamity, the Dao Source World Tree had weakened to the verge of withering and death, constantly wavering between life and death.
To your side of the All Heavens universe, the Dao Source World Tree was not merely a high-grade supreme treasure. Its existence carried an extraordinarily special meaning.
After reading the records concerning the Plague Realm, you understood from your own perspective that the Dao Source World Tree was akin to the "immune system" within a human body, inseparably tied to the entirety of your All Heavens universe. Forget the Dao Source World Tree completely withering away—even weakening slightly would leave this universe plagued by countless maladies!]
[It was precisely after that Great Darkness Calamity that things such as the Plague Realm, among others, began appearing with ever greater frequency. This, too, was caused by the absence or weakening of the immune system.
Only by the Plague Realm's abilities and scale could one further determine whether it was a serious illness or a minor ailment to the universe. While the Dao Source World Tree still existed, falling seriously or lightly ill had been perfectly ordinary. But after losing the immune system, these maladies became exceedingly "fatal."
The most direct manifestation was that living beings from other worlds could no longer use ordinary methods to eliminate a newly emerged Plague Realm outright. Instead, they had to painstakingly deal with it according to the rules of each different Plague Realm—and could never cure it at its root...]
[The appearance of a Plague Realm would naturally make you uneasy, yet everyone still believed in the principle that when the sky collapsed, tall people would hold it