The Between

The Between can best be described as an infinite void. Much like the Astral Plane, you can travel in any direction, but instead of floating, you walk along any axis you wish.

The Between has a stable climate in most parts of it, unless you happen to find yourself in a section that contains a place with climate or weather that falls on an extreme side of the spectrum.

Many of the world's strongest foes are here, along with every timeline that has died; which means that Every Big Bad and deadly plants and animals are here.

The Between is a natural Realm. It's where things get sent when a world dies. Kiev (now known as @Ulgaroth) found himself here, as an entity that only existed outside of time after a time travel ritual went sideways. Over time he became the God of the Between, and has ruled over his domain ever since.

A little after the beginning of what historians now call the Dark Years, The Elders and some of their allies sent those who had either committed great evil, or were determined to be threats to the world, to The Between as their eternal imprisonment; So they created @Kakuriyo to exist as the gateway to The Between. Kiev detested this of course, as The Between was a natural phenomenon and not to be a prison, but The Elders had moved along with the plan anyway. An entrance to The Between is not supposed to exist, So they made Kakuriyo a pocket world that technically did not exist on the world.