The creation of the Transmundane was not a natural process. Using the immense powers of the combined Romatron, Deristroll, and Kurss, Terox managed to absorb all of this within himself, though most of his energy was too unstable. If he had used this all at once, the effects would've been catastrophic, killing him instantly and ripping through various dimensions.
Terox used this energy to escape with what little life force he had left. He formed a pocket dimension completely composed up of the combined powers of everyone in order to stabilize it and slowly seep into Terox himself to repair him and slowly fuel him with more energy; the process began to grow even more quicker.
Terox could use the dimension's very power to warp it in any way he wanted to do, purely based on his imagination and how strong the concentration of energy existed.
The general appearance of the Transmundane alters itself. The main depiction of it is essentially an infinitely moving void of sanguine red and black energy consisting of free flowing energy that could form itself into surfaces. Stone slabs and floating rock are manifested all around, floating in and out and changing shape on occasion. The sky has "rips" or "weak spots" that show rips in the fabric of space time, either showing the view of stars or windows into other dimensions.
There are also inconsistencies with how stable the energy is; some bits of it appear to move sporadically, while others are more calm and barely move around.
- The general appearance was inspired by Apocrypha from Skyrim: Dragonborn.
- The idea of the Transmundane was thought of for quite some time, but it was never implemented until the movie.