The Library: Mana

"Welcome back, I hope you're all ready for your lessons in magic," the Librarian began with a welcoming smile as he- "Oh, you don't have to keep me seated in the cozy corner from before. I'm about to start a lesson and would like to give demonstrations, so please bring me to a more practical area."

The Librarian was stood in what seemed to be a small field surrounded by wooden practice dummies. The area was still on the floating island, yet it was nestled within the boundaries of the everchanging library itself. This field was a curious place—a blend of nature and study. The grass underfoot was lush and verdant, swaying gently as if in a breeze, despite the absence of any discernible wind. The field was encircled by tall, ancient trees whose roots seemed to dig into the very fabric of space itself, anchoring the area to the floating island. Scattered around the field were wooden practice dummies, their surfaces worn smooth from countless impacts, yet sturdy and resilient, as though they had absorbed the essence of every spell and strike they had endured.

In the distance, the boundaries of the field blurred, where the ever-changing library walls shimmered and flickered, a reminder that this training ground was both a part of the library and separate from it—a paradox within a paradox. The sky above was a swirl of colors, shifting from the deep blues of twilight to the fiery reds of dawn, never settling, always in flux, mirroring the chaotic yet controlled nature of magic itself.

"Thank you," the Librarian said with a light smile, as he prepared to begin the lesson. He stepped forward, his hands clasped behind his back. "Now, to understand magic, we first need to understand mana. What is it? Where does it come from? How does it work?" He paused, snapping his fingers as images materialized in the air around him—illustrations of the inside of various beings, highlighting veins and channels through which mana might flow.

"So, you see, mana is the life force of one's—" He stopped abruptly, a hand coming to his mouth as he burst into chuckles. "Ah, sorry, sorry, that was a hard lie to keep up," he said, waving his hand to dismiss the images from the air. "That's how it usually goes in fantasy stories, but that's not how it works here."

He snapped his fingers again, and this time, the image of a small sun, no larger than a baseball, appeared before him. But this was no ordinary star. It was a pure black sun, an ominous sphere of darkness that seemed to absorb light rather than emit it. "This is the Black Sun. And since its first letters are capitalized, you know it's important," he said with a light smile. "This image is not to scale, by the way."

The Librarian pointed at the black sun, its dark surface rippling slightly as though alive. "This is the source of all mana—the mana in the atmosphere, in the bodies of people, animals, and other life. All of it originates from this."

He continued, his tone becoming more serious. "But, just as you don't get sunlight directly from the sun—because it would be a deadly laser—you don't get mana directly from the Black Sun. Its energy is lethally poisonous to most, killing from the inside out, leaving you bedridden, unable to move, and withering away slowly."

The Librarian let out a small exhale. "Similar to the ozone layer around Earth that filters out the sun's harmful rays, there is an anomaly around the Black Sun—yes, around the Black Sun itself, not around Aetheria—called The Weave. The Weave, like the weaving of cloth, wraps itself around the Black Sun, feeding off its most potent and poisonous energy. It then filters out this energy, allowing only the less powerful, yet still dangerous, energy to enter reality. And that energy," he said, his eyes gleaming with the weight of his words, "is what we know as mana."

"As for how this mana came under the control of various beings in reality, well... that's a whole other topic. But to keep it brief, it's due to evolution," the Librarian began, his tone shifting to one of explanation. "Initially, spirits—beings made entirely of mana—came into existence. People harnessed these spirits to perform magic, which later evolved into what we now call Spirit Arts. Then, after countless years—even I don't know the exact number—there were some who began to use magic without relying on spirits, instead drawing upon the mana produced within their own bodies. This is now the primary method by which most beings wield mana."

With a snap of his fingers, the Librarian conjured a detailed image of a human's internal anatomy, showing the intricate network of organs. "Inside the body—and this applies to everything, not just humans—mana is produced by various organs," he explained, his finger tracing the outline of the image. He paused, then pointed directly at the heart, which seemed to pulse with a faint, ethereal glow. "The heart is the most significant producer of mana, a veritable engine of magical energy."

He then gestured to the appendix, which, unlike its usual representation in anatomical studies, glowed brightly. "And surprisingly, the second most productive organ is the appendix. Not such a useless organ anymore, huh?" he quipped, a hint of humor in his voice.

Hovering his hand over the rest of the organs and bones, the Librarian continued, "As for everything else, while they do produce mana, it's far less than what the heart and appendix generate. Even combined, the other organs don't come close to the output of these two. For the sake of understanding, let's say the heart produces 15 points of mana every second, while the appendix produces 10. Remember, these numbers aren't exact; they're just for the sake of illustration. The remaining organs and bones might produce anywhere from 0.1 to 1 mana each, so I won't bother ranking them in detail—they simply aren't as significant as the heart and appendix."

He waved away the images with a graceful sweep of his hand. "Now, I'm sure some of you are wondering, 'Mr. Librarian, if organs and bones produce mana, does that mean species with more or larger organs and bones generate more mana?' And to that, I say yes—at least to the 'more organs and bones' part. Interestingly, size doesn't seem to matter much, but the quantity does. The more organs and bones a species has, the more mana they produce internally."

"But this can sometimes create problems. You see, you don't want more mana inside you than your body can safely hold. Remember, mana is still poisonous in large quantities." With another snap of his fingers, a new image appeared: a sealed container slowly filling with water, representing the build-up of mana within a body.

"Much like how this container has a limit on how much liquid it can hold, every individual has a different capacity for how much mana their body can contain," the Librarian explained as the image of the container continued to fill, with water rising toward the brim. "And if you don't expel that mana, it will keep accumulating, filling and filling until..." The container groaned under the pressure, then suddenly burst open, sending water crashing outward, shattering the container into pieces. "This will happen. Well, not exactly—you won't explode, but you'll slowly die a poisonous death. So, remember to expend your mana, because there are better ways to commit suicide," he added with a smirk.

"However, don't be too eager to expend mana too quickly, either. Doing so leads to mana exhaustion, which is often compared to giving too much blood or whatever. But that analogy has always been flimsy." Ouch. The Librarian ignored the narrator's comment and swiped away the shattered container's remnants with a casual wave of his hand. He then snapped his fingers, summoning new images into existence. Four miniature humanoid figures appeared on a track—two on a 100-meter course, and two on a 500-meter course.

"It would be more accurate to describe this as sprinting versus jogging," he continued, as the figures on the 100-meter dash began to run. "Using a lot of mana quickly is like sprinting—a burst of speed to quickly reach your destination or, in the context of a magical battle, to quickly end the fight." The sprinter crossed the finish line first, while the jogger's miniature evaporated before reaching the end. "Yes, you used a lot of stamina, and you're most likely very tired from running, but you won. However..." 

He gestured to the figures on the 500-meter dash, which started their race. The sprinter dashed ahead, reaching 100 meters first but soon began to slow down, breathing heavily. "Even if the sprinter is more fit and has more stamina or in the the context of a magical battle, more mana," the Librarian continued, "they're burning that stamina/mana too quickly." The miniature sprinter figure began to stumble, its movements becoming sluggish. Meanwhile, the jogger, maintaining a steady pace, gradually caught up and eventually overtook the sprinter, crossing the finish line with energy to spare.

The Librarian pointed to the jogger's figure. "In this scenario, using mana too quickly—like sprinting—can lead to exhaustion before the task is complete. In a battle, this might mean running out of energy when you need it most, leaving you vulnerable. On the other hand, pacing yourself with your mana use—like jogging—allows you to maintain your strength over a longer period, ensuring that you have enough energy to finish what you started."

With a final wave, he swiped away the images, clearing the air before him. Clasping his hands together, he gave a satisfied nod. "Well, that's enough for this week. You now understand how mana works, where it came from, and how it's produced. Next time, I'll delve into the actual mechanics of magic. But for now, goodbye," he said with a warm smile. "And happy learning."