In the Seven Towers Alliance's public course, *Plane Science*, there was a detailed description of the Cosmos's cornerstone: the "Sea of Magical Power."
The Sea of Magical Power birthed countless Planes, like bubbles floating on the ocean's surface.
The vast majority of them were unremarkable ordinary Material Planes. Only about a tenth were special Planes possessing unique Laws.
There were also certain Planes—the most exceptional among the special—that were renowned throughout the entire Cosmos.
The Abyss was exactly this kind of multi-layered forbidden Plane.
It was the source of chaos and evil, brimming with chaotic Magic Power.
Its environment spontaneously gravitated towards filth and the bizarre, inhabited by countless Demons and other vile creatures.
