Incorporeus

Outside of the Purgoran Shield, the emptiness of dark space is known as Incorporeus. This area is different to Vacuos in that it is not actively harmful to life; rather, Incorporeus has no established time or space to exist within. It is an infinite liminal space within which only beings with no attachment to earthy dimensions are able to perceive or act in any way.
The planes of Materium, the Feywild, and the Shadowfell all exist outside of the Purgoran Shield in the space of Incorporeus. To leave the dial of one of those planes is to immediately exit "existence" itself: a creature leaving those planes without entering the Shield immediately would be paralyzed for all eternity, left to oblivion or the whims of the terrible gods that drift outside of Corporeus, waiting for a hapless mortal to toy with.
In many ways, this is a far worse fate than simply being instantly torn apart by the forces of Vacuos.