Dream Plane.
Despite suffering devastating damage in the "World Collision" long ago and becoming a vassal plane of another universe, the Dream Plane was still a vast, boundless world to most Mortal Civilizations. It possessed the endless depths of outer space, countless ancient galaxies and newborn stars, as well as innumerable dark regions buried in the deepest reaches of space that no one had ever set foot in.
At the center of the universe, the ancient nebulae had almost entirely transformed into waste heat. The once-brilliant galaxies had become vast stretches of lifeless shadows and ashen remnants. Light was fading, becoming an extremely precious resource here: one by one, dying stars dotted the profound darkness with what little light remained, each cluster of stellar embers serving as a fortress stronghold. These celestial bodies, barely collected and ignited from the nebular waste, were exceedingly rare. They gazed at one another from tens or even hundreds of thousands of light-years apart. Their candlelike glow could neither illuminate this forgotten universe that was gradually entering death, nor nourish any life—at least, not conventional life.
Without life, there could be no minds in motion or activities of thought, and the evil power within the cage had no chance of escape.
Thus, the cage remained silent year after year, guarding the passage of time in soundlessness.
But this place was not entirely devoid of life.
The "Night Watchers" who guarded the cage in the darkness lived here. They built fortresses around clusters of stellar embers, layer upon layer monitoring the Abyss cage's deepest darkness, listening for even the slightest sound beside them.
Deadly silence was the cage's normal state. In the cold, lifeless expanse of space, there was not the slightest sound. Even the tremors of starlight were strictly controlled. Nor did any Mortal Civilization