When Plan A Fails..

The void. A different form of space which superimposed over the space where most entities lived.

Contrarily to normal space, the void was fragmented into pieces which grinded against one another chaotically. That constant grinding would then cause the space to fracture, and force rifts to open constantly.

In order to help people understand how the void worked, the experienced cultivators that were able to comprehend it, would describe it as a universe made of mirror shards.

Just like the direction in which a mirror shard was pointing towards determined what a person would see reflected on it, each fragment of the void was connected to a point of the more stable space.

The slightest motion of one fragment would force the ones it was in contact with to grind, causing a chain reaction that would propagate through the entire void for the the rest of eternity.