The Nascent World Fragment.

The pyramid that they formed is invisible of course. But it is very important that they position themselves this way. It is so that the artifact that they are building won't collapse from an imbalance of spatial compression. At least that's what Soverick said. 

They understand what he means and they agree with it. The spatial compression tangent is just one of the things that need to be in harmony for them to successfully build this artifact. There are a slew of other factors that need to be balanced too. 

This artifact, or its nascent form, is a sphere of energy and matter in a state of transformation flux. At the very center of the sphere is a white core. It is the authority of the Celestial Supreme. It is the foundation of the entire artifact. All the pressure of the other layers of the sphere rests on it.