I looked through concept arts, which have been shown before game release. They all depicted the same portal surrounded by iron plates…
Which are exactly the same as that Mr. Eye has!
Also portal has gears inside, the same as those in his eye.
In fact, portal had to be in his eye. This means that initially Netherverse was inside Mr Eye, or other spirits could in some way be a part of his body. The third picture shows how the energy beam breaks the surface of the planet from the inside, so the spirits have been released under the ground, maybe in Azeril caves. This is fundamentally changing the story.
Game's Extras has art where Nethers wore armor in Ratchet's dimension.
This armor is the same by the color and appearance as this canceled character robot:
I found him/her in the folder Villains, so it's not regular enemy or Prog bot prototype (which is in the folder Enemies). This led me to the theory that in the original script Vendra was alone, and made the robot to gain herself a company; who later replaced by her brother.
Azeril caves concept art shows this place, where robot parts lie, and a strange device on the wall:
What do you think about all this?