The Reality Form is made up of a bunch of Distant Realities that warped into The Space and escaped, eventually surrounding The Space entirely. They have no life, because all that life died when The Distant Realities escaped The Space. Most of these realities are quite sizable, the biggest one being over 10000e+10000 googolplex times longer than The Honeycomb. Others, however, are only about as small as Never.
The temperature also varies between each Distant Reality. When the Distant Realities entered The Space, The Ultimate SUN messed up the temperature of some of the realities, causing them to become a scorching wasteland. That also killed many of the lifeforms in there.
It is unknown yet how the Distant Realities warped all the way out of The Space.