Remus was briefing Grain before his departure.
He explained that once he went in, there would be no coming out until he managed to comprehend Spatial mana.
He would then have to make his own tear back into their own world.
Once inside, he should find a sprawling environment, with hundreds of different species. A few of them had even developed societies and have a hierarchy, along with their own language and civilizations.
Nearly a million years had passed in the separate space, creating an entire world.
It was five hundred kilometers squared and had large mountains, deep valleys, and bodies of water.
The entire space was surrounded by a white veil, keeping anything from going beyond it. In order to make it to the veil, one would have to go through a treacherous mountain range or fly. If one did chose to fly, they would also have to avoid the constant thunder storms and tornadoes.
This was all by Remus's design.