"Trace On"
So far, in terms of magical spells from fiction, no spell has made better overall sense than Emiya Shirou's "Trace On", which he learned from Emiya Kiritsugu: the one spell that Kiritsugu would consent to teach his son, his compromise with himself. Kiritsugu had come to despise magic and mages and yet his son wouldn't let him alone until he learned that one simple and useful spell.
One magic spell can destroy the world. I'm not kidding. I've come to realize this truth about "true magic", which one feels instinctively is a legitimate concept or category. The Arthur Clarke cliché is wrong, preciously wrong: magic and technology are interrelated but they are always distinguishable from each other. Technology always seems like it's approximating magic, catching up to magic, while the tantalizing possibilities of magic race ahead of technology, always just a bit out of reach. And thus one can easily see that a "true magic" spell, something that can be wielded in a few moments any time the magic-user wants, can do immense damage beyond what technology can manage, for magic permits exceptions to the predictable actions of technology and machines.
An ordinary human being has a gun pointed at them and the desperate human being plugs the barrel with a piece of paper. What effect will that have? None. What if Emiya Shirou plugs a gun with a wad of paper? The gun blows up in the user's hands.
Think of everything in the world, every solid object, that's required to break in some consistent way. What if Emiya Shirou applied "Trace On" to the paper tape at the end of a footrace? The race wouldn't end properly! That's a silly example but now imagine Shirou applying that strengthening ability to, oh, sheets of plastic or paper in an industrial context, gumming up an entire factory because suddenly it can't cut any boxes open or rip open any packages.
I've never seen Death Note but I feel like I get the premise of the show, instinctively: the shinigami's stray "death note" book has world-ending consequences. But even very small magic powers also have world-ending consequences. The machinery of the contemporary human world, Earth 2024 (as it seems), requires utmost predictability in order to achieve its simulation of magic. Corporations have fallen in love with "just in time" scheduling of their operations, i.e. requiring everyone along the supply chain to be always ready to pounce on any request or transfer, and that can only work as well as it does because of the predictability of machinery. Gumming up even one key machine or structure in the process has the potential to cause a major blockade. I'm curiously reminded of the container ship that got wedged in the Suez Canal, one of the world's most important bottlenecks in its supply chains.
And somehow I can almost imagine "Trace On", persuading the atoms and molecules to shift just a little way this and that, bonding with each other temporarily perhaps, conferring a sudden rigidity and crystallinity to materials that otherwise lacked them. It's a sensible magic spell all right, and it has a logical consequence: "projection". If you can impose added structure onto a material, then perhaps you can duplicate the structures of materials as well, which Emiya Shirou does. The evolution of that skill is not arbitrary, but suggested by the possibilities of the simpler spell.
See, ma? It is possible to explain why magic "makes sense" in fiction! I feel like I've been working on this problem for...decades, trying to justify an age-old intuition. Bad magic writers (q.v. Jo Rowling) think of magic as arbitrary, anything-goes stuff, but that's not true. Chaos and discord are "anything goes" but magic has structure. Magic needs to be consistent and sensible in fiction in order to be believable. And Nasu...I gotta say, whatever else his faults as a writer and a person, he's careful about writing magic, and thus he's always in (or near) the realm of the plausible from what I've seen.
~Chara of Pnictogen
