You ask a question which is, on a fundamental level, difficult to answer. A Flatlander such as yourself simply lacks the context to conceptualize the looming vastness that lies just beyond the edge of your limited perception and the grasping tips of your dimensionally shackled fingers. Imagine for a moment trying to explain the concept of the grandeur of the material universe as you know it to a shoebox full of moths who can only comprehend smells and you would have an analogy that is, at the very best, ironically flawed.
The Void is.
Though, perhaps, I could describe what the Void isn't?
It is not a dimension. A dimension is little more than a degree of freedom that blind, crippled little motes of consciousness and hunger such as yourself blunder about within heedlessly without meaning or purpose. You are likely familiar with three, plus a fourth you so quaintly call time. The Void is not these things. The Void transcends these things.
It is not another universe, parallel or otherwise. A universe would be simply that, another universe. Another chaotic jumble of slowly cooling matter, wandering photons, arbitrary physical constants, and information inexorably decaying under the touch of entropy. Another soupy panoply of stuff winding down toward the ignoble demise of heat-death. The Void is not so bound by such laws or restrictions.
It is not simply 'the space between dimensions', a useless phrase if ever the was one. Space has no context within the Void. Time has no arrow. Malzahar does not see the future by gazing from the present into distant aeons, he sees the future because within the Void such distinctions have no meaning. There is only what IS.
The Void IS.
The story is already written.
And the Runeterrans, in their blissful ignorance, in their infantile blindness, have not yet read the final lines of the final act.
By the by, do enjoy playing with that new Void Portal item. You can rest assured that there is nothing nefarious about it to speak of.
