Edge of Reality

The Edge of Reality is a location not just in the universe Htrae takes place in but in an infinite amount of other universes. Here all their laws mix together making anything possible. It exists where the edges of infinite universes converge and is the only known way to travel between them.

Reaching the Edge of Reality
The distance to the Edge of Reality differs depending on where the habitable world is. In Htrae it is many light years away  but still somewhat nearby relative to some other universes. In Burning Destiny the world is adjacent to the Edge of Reality making it easily accessible.

World Laws

In the Edge of Reality itself all laws of every universe converge allowing everything to operate at once. What this means is that a being such as Htrae's Wizard can still utilize his powers and teleport as he pleases. But if he were to teleport through to a habitable world in another universe the trip would be one way. As his magic is founded on Htrae's laws it would be unable to be used in a new universe.

While this location is not easily accessible to Htrae those with knowledge of it can reach it relatively easy in the Burning Destiny universe, this means that the world of Burning Destiny is one of the few locations where a two-way trip can be possible, incidentally this close proximity may be responsible for some of the universe's problems.