Magical Corruption

It is less a prophecy so much as a prediction, but many who believe that magic is a poison among this world also believe it will be its downfall. They abstain from magic because they believe its use will bring about the end of their realm even faster. Whether or not this is true is unknown to the residents of the Upper Realm.
Many believe that magic was brought into their realm and has been slowly poisoning the lands. Places like the wandering wilds or diseases like Arboria can only be symptoms of something evil, they reason, and because magic is at the root of both, that must be the source.
What magic will drive the realm into becoming is debatable, but most expect this plane will become unlivable. One prominent Mortal, of the modern non-magic-boasting Mortals, predicted that “magic will consume our land and our souls until we are nothing. It will feast on our bodies, burn through our veins, and set this realm ablaze!”
Even Magicians, when they speak openly among themselves, can’t deny that magic has an unruly side. It has taken centuries of trial and error to tame magic to the level it exists now, and they live in fear of someone who may circumvent the habits of magic and unleash a truly uncontrollable chaos upon the realm. That is why they keep their magical ways and understanding to themselves. Very few actually know the ways in which magic can be tapped without the use of a runeshaper, and that knowledge is dangerous. To protect their secret but solid foot in society, Magicians work carefully to ensure that non-Magicians believe magic can only be accessed through the runeshapers.
But whether the realm will fall to flames or chaos, only the truly ignorant believe that the end of the realm will not be brought about by magic (for just as magic created the realm from nothing, magic will remove it as well).