The medical section of the library was not visited frequently. I knew this because the dust on the shelves was considerably thicker than in other areas. Texts on bodily diseases and ailments were apparently not a priority for cultivators who believed that absolute power was the answer to every problem.

  Idiots.

  I had spent three days designing the basis for Xiao Yue’s technique. Three days of reading about meridians, energy flows, and accumulation patterns. Now I needed something different: something that traditional masters would never consider. I needed to study what goes wrong.

  I took the first text from a shelf that clearly had not been touched in years. The title was promising: Diseases of Qi: Diagnosis and Treatment. The author was a man named Physician Shen, who had apparently dedicated forty years to documenting rare medical cases.

  I opened the book and began to read.

  The first section described a condition called Rebel Meridian. The symptoms were clear: the cultivator’s own Qi attacked their meridians from the inside, causing intense pain and eventually partial paralysis. Treatment required the intervention of a specialized alchemist and an experienced physician.

  Interesting.

  I continued reading. There was another condition called Elemental Rejection. It occurred when a cultivator with a natural affinity for one element tried to force techniques of an opposite element. For example, someone with a strong affinity for ice attempting to master fire techniques. The body literally rejected the foreign Qi, causing fever, vomiting, and in severe cases, permanent damage to the meridians.

  My brain began to make connections. This sounded incredibly similar to the autoimmune diseases of my previous world: lupus, rheumatoid arthritis, Crohn’s disease. They all followed the same basic pattern: the body’s defense system attacking its own tissues. I was not a doctor, nor did I have deep knowledge of immunology, but I had read enough business articles about pharmaceutical companies to understand the basic concept: the body gets confused; it identifies something of its own as a threat and attacks it.

  And if that principle applied in a world with Qi...

  I kept reading with renewed interest. I found more cases: Corrupt Qi Poisoning, Fractured Meridian Syndrome, Auto-Induced Foundation Collapse. All followed similar patterns. The cultivator’s Qi, for one reason or another, stopped functioning correctly. Instead of strengthening the body, it damaged it.

  An idea began to form. If I could understand how these diseases worked, I could artificially replicate the effect. Not the full disease, as that would be too complex and dangerous, but the basic principle: confuse an opponent’s Qi, make it unstable, and interrupt its natural flow.

  I pulled out my notebook and began to take notes.

  Three hours later, I had pages full of diagrams and annotations. My hand ached from so much writing.

  The technique I was designing was theoretically simple but practically complex. It was based on introducing a small amount of foreign Qi into the opponent’s system. Not enough to cause direct damage, but enough to confuse the enemy’s meridians. The result would be that the opponent’s body would start treating its own Qi as a threat: momentary interruptions, continuous drainage, and an inability to execute techniques correctly.

  And the beauty was that the stronger the enemy cultivator was, the more powerful the effect would be. Their own Qi would work against them. It was perfect for Xiao Yue, whose style favored control and precision over brute force.

  But there was a problem: I had no idea if this would actually work. It was pure theory based on analogies from a completely different world. It could be brilliant or it could be completely useless. There was only one way to find out.

  I closed the book and tucked away my notes. It was time to find Xiao Yue.

  I found her in the pavilion’s training garden. She was practicing basic forms, moving with that fluidity she had developed since she started using my manual. Liling was sitting under a nearby tree, watching with a critical eye.

  "Kenji," Xiao Yue said as she stopped her practice upon noticing my presence. "Have you managed to finish the draft?"

  "I have something we can consider an initial outline," I replied as I approached the center of the garden.

  Her eyes showed a spark of genuine interest that wiped away any trace of previous fatigue.

  "Is it ready already?" she asked with a mix of surprise and expectation.

  "It is an experimental proposal. It is very likely that it will not work on the first try," I warned to moderate her expectations.

  "You always maintain that characteristic optimism of yours, young Kenji," Liling commented with a smile that suggested a bit of friendly teasing.

  "I am a realist. There is an important difference between negativity and the objective evaluation of risks," I replied while looking for a place to set my notebook.

  Xiao Yue walked toward us. She wore her usual training robe, which left her back partially exposed due to the design we had agreed upon previously. She had grown accustomed to practicing that way since our first detailed observation sessions; she claimed that this lack of coverage allowed her to be much more aware of her skin temperature and the direction of her internal Qi flow.

  "Show me what you have designed," she requested firmly.

  I opened my notebook and proceeded to explain the energy flow diagrams I had traced in the library.

  "I have decided to call this technique Withering Flame. The central idea is to introduce your own fire Qi into the opponent’s circulatory system following a specific frequency. The goal is to irreversibly confuse their meridians during combat," I explained while pointing to the pressure points in the drawing.

  "In what exact way am I supposed to confuse them?" Xiao Yue asked while frowning, trying to understand the logic behind the scheme.

  "We will make their own Qi be identified as a biological threat by their defensive system. Their body will react by rejecting its own energy. This will cause interruptions in the flow of their techniques and a constant energy depletion that the enemy will not be able to explain," I detailed calmly.

  Xiao Yue studied every line of the diagrams with a concentration that seemed to isolate her from the rest of the world.

  "That structure seems incredibly complex to execute under pressure," she finally admitted.

  "It is; I am not going to lie to you about that. But from a theoretical standpoint, it should work without errors. The longer the confrontation lasts, the weaker your opponent will become while you maintain your physical integrity," I added to motivate her.

  "What is the exact process for physical execution?" she wanted to know.

  I turned to the next page of the notebook where I had drawn the detailed sequence of necessary body movements.

  "First, you must accumulate Qi at your central point, right here," I said, pointing to the base of her spine on the diagram. "Then you must force it to circulate following a spiral pattern that creates an unstable resonance. When your fire attack makes contact with the opponent’s skin, that vibratory instability will automatically transfer to their meridian system."

  "That sounds almost as if I were poisoning their internal energy," she commented with a pensive tone.

  "It is a similar process in result, but very different in mechanism. Poison is an external agent that damages tissue. What I am proposing uses the enemy’s own defense system to destroy them from within," I corrected precisely.

  Liling had stood up from her spot and approached to look at the drawings over Xiao Yue’s shoulder.

  "Where on earth did you get such a twisted idea?" Liling asked curiously.

  "I spent my time studying documented medical diseases in the ancient archives," I replied simply.

  "You studied diseases to create a combat technique?" Xiao Yue inquired with surprise.

  "There are medical conditions where a cultivator’s Qi attacks their own energy channels. I thought that if I were able to replicate that effect in an artificial and controlled way, I would have a definitive weapon in my hands," I confessed.

  "That makes you a terrifying person at certain times, Kenji," Xiao Yue concluded as she closed the notebook.

  "I will accept that as a recognition of my work," I said with a slight nod of my head.

  "I am not entirely sure it was a compliment," Liling added while letting out a nervous laugh.

  "I am not certain either," Xiao Yue admitted. "But I recognize that the idea is interesting enough to try."

  She handed the notebook back to me and adjusted her training robe with determination.

  Unauthorized duplication: this tale has been taken without consent. Report sightings.

  "When do we start the practical tests?" she asked.

  "Right now, if you feel you have the necessary energy," I replied as I looked around the garden for a testing target.

  "I am always ready to move forward," she stated.

  We walked toward a corner of the garden where a young bamboo with a thick, vibrant green stalk was growing. It was the perfect specimen for our initial tests. It was sturdy enough to withstand the physical pressure of an impact, but it possessed the biological sensitivity necessary to show visible effects if the Withering Flame managed to activate correctly.

  "Listen carefully," I said as Xiao Yue positioned herself in front of the bamboo trunk. "The process is as follows: start by accumulating Qi in your central point following the method you have already mastered perfectly."

  She nodded in silence and closed her eyes to concentrate. After a few seconds, I could perceive the characteristic golden glow emanating from the area between her shoulder blades.

  "Well done. Now, instead of allowing the energy to flow naturally toward your arms, I want you to force it to circulate following this specific pattern," I said while tracing the design in the air with my index finger. "It is a counterintuitive movement. It is very likely that you will feel a strange sensation in your channels."

  "What kind of sensation should I expect?" she asked without opening her eyes.

  "Something like trying to write a long letter with the hand you do not usually use," I exemplified.

  "That sounds wonderful for my patience," she joked.

  Xiao Yue tried to force her Qi to follow the new circulation pattern. I watched closely as her energy began to move across her back, reached her shoulder, and then stopped abruptly before reaching her elbow.

  "It has completely dispersed," she reported with a note of frustration in her voice.

  "It is a normal result for a first attempt. Try again more calmly," I asked her.

  She tried five consecutive times over the next ten minutes. In each of those instances, the Qi lost its cohesion and dispersed in her system before completing the resonance cycle I had designed.

  "This seems like something impossible to achieve," she muttered as she opened her eyes and looked at me with weariness.

  "It is not impossible. It is simply a task of high difficulty. Your body has spent years circulating energy in a specific way, and now you are asking it to break its established habits," I explained to reassure her.

  "Do you think you would be able to do it if you were in my place?" she challenged me with a defiant smile.

  "I lack the capacity to circulate even a drop of Qi, so my failure would be absolute and much faster than yours," I admitted honestly.

  That response managed to draw a small laugh from her, which eased the tension in the atmosphere.

  "You have a good point there," she conceded.

  She kept trying for the next twenty minutes. Liling watched the process in absolute silence, but I could detect the concern growing on her face as she saw her mistress's effort.

  After half an hour of failed attempts, Xiao Yue showed evident signs of exhaustion. She was sweating profusely and her breathing had become erratic. Her back glistened under the sunlight due to the accumulated moisture. I took a linen towel that Liling had brought with her and approached her.

  "It is necessary for you to rest for a few minutes, Young Mistress," Liling suggested with a firm tone.

  "I have the strength to continue," she insisted while trying to catch her breath.

  "You will not be able to continue if you end up fainting from excessive depletion of your reserves," I countered.

  Xiao Yue finally stopped and let her shoulders drop. I approached from behind and proceeded to gently wipe the sweat from her back with the towel. I could feel the intense heat radiating from her skin, a heat that was not just physical but came from the agitation of her internal energy. She was working with a dedication that bordered on stubbornness.

  "Thank you," she said in a very low voice as she felt the contact of the towel.

  "Do not let frustration defeat you now. This is a new process for both of us. I never expected us to get positive results on the first day," I reminded her as I finished my task.

  "Then why do I feel like I have failed in my duty?" she asked bitterly.

  "You feel that way because you possess a perfectionist nature. That is one of your greatest virtues as a warrior, but it also means you tend to be too hard on your own learning processes," I analyzed as I stepped back a few paces.

  Xiao Yue turned to look me directly in the eyes. Her face was flushed from the effort.

  "What will happen if the technique does not work at all? What will we do if your theory turns out to be completely incorrect?" she inquired with a vulnerability she rarely showed.

  "If that happens, we will simply have learned something new about what does not work and we will look for a different path. That is how human knowledge progresses. We fail, we make the necessary adjustments, and we try again with more information," I replied calmly.

  "It is not a feeling I enjoy. I do not like failing at what I set out to do," she confessed.

  "No one likes failure. However, it is an inevitable part of any innovation process," I concluded.

  Xiao Yue nodded slowly as she processed my words. She drank a generous amount of water from a ceramic jar that Liling handed her promptly.

  "I will try one more time," she announced after five minutes of rest. "Just one more time for today."

  Another hour passed.

  Xiao Yue repeated the cycle of the technique over and over with admirable tenacity. In each attempt, she managed to advance a little further in the spiral circulation pattern, but some error always arose in the final stage. The Qi would disperse before contact or lose the resonance frequency necessary to become unstable.

  My notebook was filling up with additional notes. I wrote observations about the exact points where the flow broke, made potential adjustments to the design of her hand movements, and tried to calculate the relationship between her heart rate and the stability of the Qi.

  Despite my analysis, frustration continued to grow in the garden. I could see it in the excessive tension in Xiao Yue’s shoulders and in the way she clenched her fists between each failed attempt.

  "I think it is better to leave it for today and resume practice tomorrow," I suggested finally, seeing her physical state.

  "I said no," she responded with a tone of voice I had never heard from her before. It was a mix of absolute determination and a frustration that threatened to overflow. "You are going to be here watching my every move, enduring the sight of my constant failures without complaining, so I also have the obligation to endure this practice until I obtain something concrete."

  I was left speechless by such a declaration of principles. She returned to her position in front of the bamboo trunk. She closed her eyes tightly. She took a deep breath that expanded her ribcage to its limit. And she tried again, putting every ounce of her will into it.

  This time, something in the garden's atmosphere seemed to change subtly. I saw how the Qi accumulated in her central point and began to circulate following the spiral pattern fluidly. The first stages of the technique were completed without the energy dispersing.

  "Come on, Young Mistress, you can do it," Liling whispered at my side, almost breathless.

  Xiao Yue’s Qi flow now emitted a golden glow that vibrated with unusual intensity. It looked like a liquid substance struggling to stay together despite an internal force trying to tear it apart. Finally, she extended her right hand toward the bamboo trunk with a slow and controlled movement.

  During the first few seconds, nothing perceptible occurred. Xiao Yue kept her hand a short distance from the wood. The Qi continued to flow according to the planned pattern; the unstable resonance remained constant in her arm. However, the bamboo showed no signs of damage.

  She let her hand drop with a gesture of total defeat.

  "I have failed again," she stated with disappointment.

  "You have not failed at all," I intervened quickly. "You managed to complete the circulation pattern for the first time. That represents enormous progress."

  "But the technique has not produced the effect you described," she countered bitterly.

  "Perhaps the effect needs more time to manifest in a plant organism. Or maybe my theory about transfer is incorrect and we need to adjust the distance of..."

  "Kenji," Xiao Yue interrupted as she turned toward me. I could see tears of frustration in her eyes. "I sincerely appreciate your efforts, but we must be able to admit when an experiment simply does not work."

  "Grant me a moment to analyze the data from this last attempt," I asked.

  "Do it one more time, Young Mistress."

  Liling’s voice intervened unexpectedly. She had stood up and was walking toward the bamboo with an expression of absolute intensity.

  "Why should I?" Xiao Yue asked reluctantly.

  "Do it once more. But this time keep your hand much closer to the trunk. Almost brushing the surface of the bark, but without actually touching it," Liling instructed.

  "What difference do you think that can make, Liling?" the cultivator questioned.

  "Just do it, Young Mistress. Trust my intuition this once," her friend asked firmly.

  Xiao Yue hesitated but finally nodded and positioned herself again. She closed her eyes and initiated the process with a precision obtained through grueling repetition. Xiao Yue extended her right hand and, just as Liling had suggested, placed her palm barely a centimeter from the green surface of the bamboo.

  During three seconds of absolute tension, the silence in the garden was total. Then, the bamboo began to show an unsettling transformation.

  The change originated exactly at the point of influence. The vibrant, life-filled green color of the bamboo began to fade rapidly. The area turned a muddy brown and then, before our astonished eyes, changed to an ashen gray. The plant organism was withering at an unnatural speed. The grayish discoloration expanded throughout the stalk; the upper leaves lost their turgidity and began to fall. The surface of the stalk, once smooth, wrinkled visibly.

  "It is actually working," Xiao Yue whispered with awe and reverent fear.

  "Do not interrupt the flow now," I urged her as I began to take notes frantically. "Keep the vibration constant."

  The destructive effect accelerated. The bamboo now looked like a dead plant remnant that had been exposed to the elements for weeks. It was completely gray, brittle, and devoid of life. Xiao Yue finally pulled her hand away and took a step back. The withered bamboo remained standing by sheer structural inertia, but its life cycle had ended.

  Seconds later, Xiao Yue let out a cry of joy that broke the tension.

  "We did it! Kenji, it worked perfectly!" she exclaimed as she lunged toward me and threw her arms around me with an embrace full of strength.

  "I knew you would be able to achieve it, Young Mistress! It is an absolute success!" Liling shouted as she joined the group.

  "Technically, the key was Liling’s suggestion about the contact distance," I managed to say while trying to regain my personal space, though I was not bothered.

  "I do not care whose part of the idea it was," Xiao Yue declared without letting go of my shoulders. "The important thing is that the theory is a reality!"

  Liling hugged both of us at the same time, forming a small circle of celebration.

  "This is something truly incredible," Liling commented sincerely. "You have just designed a combat technique from scratch, young Kenji. That is something only the great masters achieve."

  "Well, it still requires adjustments," I began to explain automatically. "The activation time is too long and the effective distance is limited. We probably need to investigate how to project that frequency..."

  "Kenji," Xiao Yue interrupted with a soft smile. "Please stop analyzing every detail for a moment and accept that what we have just witnessed is surprising."

  I paused and looked at her. She was right.

  "All right," I conceded. "I admit that it is surprising."

  The three of us remained there, contemplating the physical evidence of our success. My mind, despite everything, was already calculating the next steps: reducing the charging time, extending the range with weapons, attacking the center of the Qi... The possibilities were infinite and terrifying.

  I opened my notebook to document the results.

  "So," I said as I prepared the pen, "the immediate adjustments I consider necessary are..."

  At that precise moment, I experienced a strange sensation. A sharp, piercing pain shot through my chest from one side to the other. It was not physical fatigue; it was a sensation of internal rupture that left me breathless.

  "Kenji," Liling’s voice sounded as if it were coming from the bottom of a tunnel. "Are you alright? You have turned very pale."

  "I..." I tried to articulate a response, but the words refused to leave my throat.

  The pain became unbearable. I felt a hot, thick wave rising from my lungs. I could not contain it. I began to cough violently.

  Blood.

  A considerable amount of blood was expelled from my lips, staining my hand and falling onto the dry ground. The bright red contrasted macabrely with the earth and the gray bamboo.

  "Kenji!" Xiao Yue’s scream was loaded with pure terror.

  My vision began to blur. The world transformed into a blur of confused colors as the circle of my field of vision closed.

  What has gone wrong?