The wind swept through the canopy, creating a rustling sound. The atmosphere was so quiet that I could clearly hear the dry cracking sound of the dead leaves being crushed under Aiselin's heels. The lady of the Shirakawa family did not reply immediately; her deep sapphire eyes narrowed slightly, boring deep into the person standing before her as if evaluating a completely anomalous creature.
"A magic book?" Aiselin repeated, her tone unclear whether it was mocking or intrigued. "You are someone with no innate mana, a mana core so barren that I can barely feel it. What do you have to guarantee that my investment will be profitable? Just that tiny ice cube from earlier?"
I took a deep breath. Here it was. The project defense round before the investment board. The only difference was that if I failed this subject, what I lost wouldn't be the retake fee, but possibly this little life of mine.
"My Lady, my mana core is indeed barren," I raised my head, looking straight into her eyes, activating presentation mode. "But the problem with current mages is that they use their bodies like a primitive capacitor—only knowing how to store and discharge mana wastefully. I am different. I don't need a massive power source. I use the principle of signal amplification."
(Prepare for an information dump, guys; if you don't want your brain to explode, skip reading this part, hehe boy)
Aiselin furrowed her brows slightly. "Amplification... of what?"
"Like an operational amplifier circuit," I began to pour out, raising my right hand to chest level. "I use my minuscule amount of mana as the input signal. Instead of directly slamming it into nature to create ice or fire, I route it through precise spatial coordinates to stimulate the kinetic energy of surrounding matter particles."
As I spoke, I focused my meager mana, forcing it to run through the tip of my index finger. In my head, the knowledge of Analytic Geometry began to be applied.
"According to the principles of thermodynamics, when the kinetic energy of oscillating particles slows down to the extreme limit, the temperature will automatically drop drastically, and the moisture in the air will condense..."
Snap.
A soft sound echoed. Right at the tip of my finger, the air suddenly turned freezing cold. The surrounding moisture gathered, condensing to its maximum, forming a small ice bead that radiated a sharp, frigid aura.
"And here is the most interesting part," I smiled, beginning to manipulate the ice bead. "I don't need to memorize complex incantations to shape magic. I use mathematical equations in 3D space."
I half-closed my eyes, visualizing the Oxyz coordinate axes right at the position of the ice bead.
"" I murmured.
Immediately, the ice bead in my hand expanded, perfect and spherical down to the millimeter, forming a sparkling ice sphere under the twilight. There was not a single bump or deviation on its surface. Its surface reflected Aiselin's astonished image.
"That is the equation of a sphere," I explained, my voice as steady as if giving a lecture in a university hall. "But what if I want it sharper? Limit the coordinates."
Crack, crack. The ice sphere in my hand suddenly shattered, then instantly restructured itself. Sharp edges protruded, turning it into an angular, cold, and flawless cube. Eight vertices pointed in eight directions with absolute symmetry.
I grasped the cubic ice block in my hand, feeling the bone-chilling yet highly satisfying cold.
"In short, I do not create ice with raw mana. I use mathematics and particle kinematics to force nature to construct the shape for me according to pre-programmed coordinates," I lightly crushed the ice block, letting the fragments fall to the ground. "That is maximum efficiency, infinite customizability, with an energy cost close to zero."
Aiselin's eyes widened, her pupils trembling slightly. She completely didn't understand what "particle kinematics" or an equation was. But the innate logical thinking of a magical genius helped her realize one thing: This theoretical system was too rigorous, too seamless to be the fabrication of a commoner.
It was a completely new foundational knowledge. And it was real.
Seeing that I was about to continue, Aiselin abruptly cut me off: "Enough." Her gaze now lacked any condescension, replaced by the sharp calculation of a ruler. "I understand." (She didn't understand a single bit). "You are not a mage. You are something... much stranger."
"Something stranger?" I smirked inwardly. "As if I want to be a mage so badly. I'm an engineer. If it weren't for that damn truck, right now I'd be sipping coffee, eating a cake, and getting ready to celebrate with the monkeys of BCA because I successfully defended my doctoral dissertation."
But before I could open my mouth to retort, Aiselin tilted her chin up, her sharp gaze cutting through my train of thought.
"The things you say are indeed interesting," The young lady crossed her arms, her slender fingers tapping impatiently against her bicep. "But I wonder if it has practical combat value, or if it's just empty theories on paper? Can this 'system' you are so proud of kill a low-level magical beast, or is it only good for making shaved ice for drinks?"
She didn't wait for my answer, glancing at the old butler who stood as still as a statue. "Sebastian. Test him. No need to use your full strength."
"Yes, My Lady."
Sebastian bowed with a motion so perfect it would make a protractor weep. He took a step forward. No killing intent. No suffocating pressure like in those fast-food isekai series. Only a spine-tingling silence.
He raised a hand and gently snapped his fingers.
BOOM.
The air around Sebastian suddenly distorted. A spherical, transparent energy membrane, which flowed like rippling water, instantly enveloped his body. It emitted low, dull humming sounds, causing the surrounding air to crack.
"Flowing Force Shield - One-star defensive magic," Sebastian spoke in an even tone, offering a polite smile. "It has no offensive capabilities, young man. It merely absorbs and disperses any physical or magical impact that touches it. You do not need to defeat me. You only need to put the tiniest scratch on this shield using your theories."
I narrowed my eyes, staring fixedly at the oscillating membrane.
If it were an ordinary mage, they would see a massive wall of mana, a despairingly unbreakable barrier against my cheap, Shopee-bought core.
But I wasn't looking at it through the eyes of a cultivator. I was looking at it from the perspective of signal processing and circuit analysis.
That shield was not a solid block of concrete. It was a flowing stream of energy. All streams have oscillations. All oscillations follow differential equations. In my mind, the old butler's energy membrane was decomposed into a 3D function graph.
"It has a frequency... An amplitude... A phase..." I darted my eyes continuously along the ripples on the shield's surface. The energy distribution wasn't uniform. To maintain a continuous spherical shape, the system had to constantly compensate for mana at intersecting points. This meant there would be nodes where the oscillation amplitude reached a minimum, and the structure became the most rigid, probably for about 0.02 seconds.
"You may begin."
"Time to act," I thought to myself.
I didn't even bother raising my hand to chant. The barren bits of mana in my core were squeezed out, running through the conversion algorithm in my brain. I didn't create a giant ice boulder to pierce the shield—that was energetically impossible. I drained the particle kinetic energy of the water vapor in the surrounding air, dropping the localized temperature below zero instantly.
Thousands, no, tens of thousands of microscopic ice dust particles formed and hovered around me. It consumed a ridiculously small amount of mana because their mass was almost zero.
"Ice dust?" Aiselin raised an eyebrow, looking disappointed. "Do you plan to use that to scratch Sebastian's itch?"
"No. I am using it to test the resonance frequency, My Lady."
I snapped my fingers. Instead of rushing straight at Sebastian like a storm, the cloud of ice dust split into dozens of small streams, zigzagging along non-linear trajectories. I was applying spatial kinematics, programming their flight paths to precisely calculate the lag of air resistance.
Tick. Tick. Tick.
The first ice dust particles hit the surface of the shield and immediately vaporized, absorbed without leaving a trace. Sebastian kept smiling.
But I smiled, too.
"Found it." The colliding ice particles sent back feedback regarding the membrane's vibration. The angular frequency of this shield was not perfect.
"Time to end this," I murmured.
The entirety of the remaining ice dust suddenly accelerated. But they no longer struck randomly. They aligned into a perfectly straight line, plunging into a single coordinate, with a time period that absolutely matched the shield's oscillation rhythm.
The first particle hit. Absorbed.
The second particle hit exactly at the moment the shield's energy was undergoing a phase shift. A microscopic ripple appeared.
The 10th particle... The 36th particle... The 67th particle...
I turned the dirt-cheap ice dust into a train of impulses continuously striking a blind spot in the oscillation equation. The force wasn't large, but the resonance was growing exponentially. It was like an army marching in lockstep that could collapse a sturdy steel bridge.
Sebastian's eyes widened slightly. The polite smile vanished. He felt his magical structure falling out of rhythm.
I channeled every last remnant of my mana into a slightly larger ice fragment, launching it along the final trajectory just as the resonance point's amplitude reached its maximum.
CRACK CRACK.
A piercing sound rang out.
Right in the middle of the butler's flawless flowing mana membrane, a small crack suddenly appeared for a brief moment. It didn't take long for Sebastian to patch it up, but it was long enough for Aiselin to see. It didn't shatter, but the structure had been disrupted for a single beat.
Sebastian froze, his eyes wide open as he stared at the small crack on his shield, then looked at me as if he were looking at an alien. He then turned to the young lady and gave a slight nod.
I let out a breath, wiping the bead of sweat on my forehead, feeling a splitting headache from running too many calculation programs simultaneously. I looked at Aiselin, who was standing petrified in her spot.
"I have completed the test, My Lady." I bowed my head, keeping my voice as calm as possible despite trying to endure the headache and my body trembling from mana depletion.
In Aiselin's eyes right now, all skepticism had cleanly evaporated. Instead, it blazed with a fanatical light, the light of a genius who had just discovered a new technological marvel that she absolutely had to grasp at any cost.
End of Chapter 4.