Plane of Magic
Imagine for a moment, that you are a mage on the battlefield of war - maybe you've been trained for battle-casting, or maybe you've not been trained in casting Magic under such pressure. Imagine this situation, and imagine you do not have the magical energy to keep casting, but still you must. Where do you reach for the magic?
Travel
Physically going to the Plane of Magic requires finding where a mage has left a magical imprint, meaning a rift is the easiest way to start.It was a moment of desperation, but I did it. I won, but in that moment, I felt like a candle where the wick burned through, but the wax had not melted. I took decades to recover, and even now, a century later, I am half the mage I was before that moment when I felt I pulled from that never-ending ocean of magical power.
Exploration
The sky is a distant dark cloudy night dancing with deep violet and reds. There are no stars, there are no moons. If I had not been granted permission to go to the Undermountains, I would believe we were in the realm of the Dwarves until looking at the land.
The land fragments we walk on are like solid water - but not ice as there is no crystaline flakes despite the clear-like watery-blue coloring. The ground is solid but rippled, but also translucent into other solid-water-land below. Between the fragments, air moves as if a liquid.
We intend to climb or dive as the case may be, further down in a few hours of the hourglass. There is no sun to watch for time except below us is the contant glow. Already, we can report our magical abilities are improved beyond even our best estimations, though the reactions between spells also appears to have exponentially intensified. Basic and common spells that were aimed between the land appear to intensify as they follow their trajectory and out of sight into the blinding not-sun.
One of the scouts went ahead, but returned confused, as if they had forgotten why they were scouting - or what scouting was.
The laws of magic are among my favourite element of worldbuilding. I usually like to make them logical and structured in my settings, but do not want them to end up feeling like mechanical or bureaucratic. Magic should set those who have access to it apart in some way, and it should be dangerous and unpredictable in some instances too. Cost something. Your Plane of Magic here has many of such elements, looks like. The notion of suicidal terrorists came to mind, in a Universe where mages can improve a spell to a point that raises it to a different power scale, as long as they do not mind in die process. Deal with mage in such a context becomes a personal instance of what nations in our world do when dealing with other that have nuclear missiles. Society would not push any mage to an edge if there is the risk of that mage "go nuclear". On the other hand, I imagine that people would be tempted to kill any mage who seems emotionally or mentally instable.
For a future concept of Corive, this is treated like a mage "going nuclear," though it's also an extremely difficult task to pull magic from the Plane of Magic - less self-harming ways involve ripping the ground beneath to create chasms, thought including that aspect is one of the struggles I have because I know more about how it works than the people of the setting's current time. XD That being said, pushing a mage too far can have disastrous consequences - the quote includes some of the costs that are only available to them because they're an elf and live longer than a human. I'm glad you enjoyed reading this and find it thought provoking - it's a very fascinating topic for me to think on, even if what I'd write for it might not go into *this* article or this Corive.
Feels like a prudent notion, to make "going nuclear" a "extremely difficult task" in your fictional world. I imagine that we would not have a consistent fictional world for very long if it was something easy to do. Probably that is the reason why the immoral notion of countries with nuclear bombs forbidden others from develop it got so much tolerance from many countries without nuclear weapons. In the end of day no sane person in our world is too keen to live in the world with easy and democratic access to Fat Boys. Reminds me a RPG scenario I once saw where any PC character could invoque a godlike power once in life, to accomplish one thing. That ended in death, of course, and was intended as a way to give an heroic end to characters. In the context of RPG games worked well enough. But got me thinking how problematic something like that would be for a society if that was an option for everybody. Any random person can commit suicide in the middle of a city an became Godzilla, or any other fantasy version of Fat Boy, for one quarter of hour more or less. Every failed relationship of middle age crisis would bring the risk of a entire city being destroyed, and all those people dying in those stupid murder/suicides would themselves have the possibility of ad more gasoline in the fire. What kind of civilization could grow in such circumstances, if any? Better not to make the access to the Plane of Magic too easy. Personal sacrifice or not.
I have no olanes on making access easy in regards to drawing on its power, and I've not nailed down how one gets there because it's supposed to be a dangerous expedition (think people going to the North and South Poles and how many people died because they didn't know what was there and how to prepare for it in terms of the unknown and danger. Except one of the biggest dangers, is the mages because magic gets exponentially stronger when used as described by the explorers who returned or sent reports in before being lost.)
An scenario of fast technological change, more or less like WW2? Except that instead of tech is magic. And there is no War attached to it (at least not necessarily). Any new knowledge able to raise the effectiveness of magic when applied will change the importance of magic in society. And the status of magic users as well, I suppose. If that change happens fast, it will cause some discomfort for the average people. Like the grow in importance of sailors in Ancient Greece, when navy power became a essential factor in war, but perhaps much more extreme.