Cheng Tian's forceful killing of the Goldfish Spirit had created no small grudge between him and Guanyin Bodhisattva.
The death of a pet fish might not have been an irreconcilable blood feud, but it was enough for Guanyin to view Cheng Tian and everything related to him through tinted glasses from then on.
That was right. Guanyin really was that petty!
Fortunately, Cheng Tian was too.
Don't assume that the Heavenly Court and Spirit Mountain forming a coalition meant they were all that harmonious. Their opposition still remained; it had merely been redirected by the existence of the Black Myth world. With a clear common objective, they appeared united against an external enemy. Once this matter settled down, the two sides would most likely return to their original state of competition... though barring surprises, the pace at which that competition escalated should slow dramatically.
Perhaps he had reached that age. Without realizing it, the shows Cheng Tian watched while eating had gradually shifted from anime, variety shows, wilderness survival, and the like to all kinds of current-affairs analysis. He himself could still be said to know absolutely nothing about politics, but after watching enough, he had more or less developed certain habitual patterns of thought and could find parallels in the development of similar events.
Had the Heavenly Court and Spirit Mountain launched a Cross-Dimensional war because they were enraged by the gods, Buddhas, and spiritual essence system of Black Myth?
Yes, but not entirely.
As the saying went, no one rose early without profit to be made. In Cheng Tian's view, the fall of the gods and Buddhas was merely the main pretext for sending troops. What truly mattered more to those two major powers was the Black Myth instance itself.
More precisely... it was the ordinary people oppressed