Magic... what was it? The essence of life, or a form of energy.
You look though books and it's one or the other. Something these two ideas become one. In stories anyways. And our world... is one of them.
It was a resource harnessed for all things. Economic advances, technological breakthroughs, and of course naturally it was something everyone wanted to monopolies.
It was possible. Since magic, can help being the imagination to life. Naturally, some were born for using it, and some not so much or at all.
When of course, the question came, if it was so abundant, why did some have non or so little in comparison to others?
Discrimination, slavery, war. It was a constant for this.
And in the end. A War broke out. Not because of this civil discprenties, but because of the craving for power. And that's when it happened.
Multiple, magical nuclear weapons went off. As well magical nuclear reactors. All seemingly went off. Desserts became radioactive waistlands, oceans levels fell 2/3ds. Rainforest, came to life. The world as they knew it was long over. And came to being a far dangerous world. Animals mutated together intimate abomination, plants began to feed on death and sap away life. Amd... the dead walked once again, now bound and controlled with machineries.
This world, had new dangerous, new factions. There was natural life as a category, which claimed plant life, then the living category, which were animals and people. Then, the undead mutated category, the walking dead atomic machines that came from magic coming to life in a pure evil way in its new form.