Quote Originally Posted by KageTokage View Post
I assumed they were just illusions conjured from memories that weighed very heavily on the minds of the two subjects we've seen used for the project, as things just abruptly return to normal once the Weapons are shut down.

They never really bother explaining how some other primals like Zurvan and Tsukuyomi completely transform the battlefield, either.
I'm going to assume it's essentially a Reality Marble created by an excess release of Aether into the air, temporarily creating a spatial distortion bubble with its own rules set up by the creature that creates it. This explains why things like E1's ultimate attack doesn't actually destroy the solar system or planet, because we're not actually there during the fight, we're in the bubble.