The Border

The Border was a special world with no inhabitants and mainly acted as a barrier.

Description
The Border had no physical appearance from The Real World. The Outside World however described it as a white almost transparent wall. It was a barrier that maintained order across all worlds, and blocking access to others. After Outside World managed to shatter it, the worlds became vulnerable to each other. This sparked the First Universal War.

Unlike most worlds, The Border had no residents and was the largest world ever recorded. It spread across literally every other world, blocking access to each other.