RNG is an incredibly powerful daemon that consists almost entirely of pure chaos. If allowed complete sway over the realm, RNG can cause nearly unsupported spires of land to rise to the heavens while creating pits to the abyss to form right next to them. If allowed absolute power, RNG is able to cause massive changes to the weather making the world freeze solid, then broil, then to freeze once again almost instantaneously. An unfettered RNG would have the power to fell all with plagues, level all with fires and tornadoes, or just make everything, everywhere, just stop. An unlimited RNG can do all of these things, or RNG could do nothing, all in the blink of an eye. To top it off, RNG has no compassion, no mercy, and no conscience whatsoever. As you may well imagine, RNG is a very dangerous god, and one not to be invoked or prayed to by the likes of us, if we know what is good for us.
The Creator knew that to have a completely unfettered RNG running amok within the realm was no better than having no realm at all. However, the Creator, in his wisdom knew how to constrain RNG to only perform its chaos when certain conditions were met, and also to limit the chaos to a pre-determined range. Using these constraints, our realm could be made to have overall predictable trends, but the day to day happenings within the realm had the variety needed to create both challenge and fulfillment. One of the most obvious manifestations of the interface between RNG and the Creator's restraints are in our weather and seasons. Winter is cold, and summer is hot, and the Creator made the seasons this way, but exactly how cold and how hot is determined by RNG who will decide this. Not even the Creator himself can tell you exactly what temperature it will be tomorrow, only that it will be "somewhere between this and that".
Using the power of RNG combined with constraints, the Creator set about creating all of the realm, all of what exists in the realm, and all Banishim. Yes, children, we are all made of the stuff of restrained chaos. When you leave here today, many of you will go out and play, but exactly where you will go and what you will do, even you do not know, do you? Do not worry overmuch about this, though. I shall let you in on a little secret. The rest of us don't entirely know for sure, either. The Creator created us, and the realm using RNG. When He was done with this, he finally enlisted the aid of the other divine agent, Our Guide.