Fuel

Winter nights in Di'an were freezing cold. There was no starlight, no moon, only a deathly stillness. Emerging from the kitchen, Xu Yuan carried a steaming meal of three dishes and a soup through the cold winter night, his thoughts wandering aimlessly. Though the culinary arts seemed ill-suited to a cold, aloof overbearing executive type like Xu Changge, the truth was that his eldest brother genuinely knew how to cook, and made good food to boot. He remembered that back after their mother passed away, their father and uncle had disappeared for a long time, leaving the four children confined to the inner courtyard. To prevent any mishaps, before leaving, the old man and uncle had set up numerous precautions within the Prime Minister's Manor's inner courtyard, forbidding anyone from entering or leaving. As the only child old enough to understand what was going on, had Xu Changge, the eldest, not cooked, the other three little ones wouldn't have even needed an assassin—they would have starved to death on their own. As his thoughts wandered, Xu Yuan unconsciously tightened his grip on the meal tray as he passed the gate to Xu Changge's courtyard. Though he was reluctant to admit it, Xu Changge really was a good elder brother. Aside from disliking using his mouth to speak, he was a good brother in every sense of the word. After all, just before being confined, he had watched with his own eyes as their mother was killed right in front of him... And even so, barely more than a child himself, he had never shown the slightest crack before his three younger siblings. "Hoo..." With a soft sigh, Xu Yuan walked past Xu Changge's door, composing his emotions before carrying the food back to his wing room. Tonight's dinner seemed a bit too lavish for Xu Xinyao alone. Five meat dishes, two vegetable dishes, and a soup. Usually, this was the spread reserved for family dinners when all of them gathered. Xu Changge had prepared so much, presumably intending a share for Xu Yuan as well. Yet Xu Yuan had no intention of picking up chopsticks, merely sitting quietly to the side, watching. As a quintessential lady of a noble house, Xu Xinyao's dining manners remained as gentle and poised as ever. She chewed slowly and swallowed quietly, making no sound. The faint clink of bamboo chopsticks against porcelain bowls became the only sound in the room. "Third Brother, are you really not going to eat?" Having swallowed a tender piece of spiced fish, Xu Xinyao looked up across the table at Xu Yuan. Snapping back to the present, Xu Yuan cast a glance over the sumptuous, tempting dishes spread across the table and shook his head with a faint smile. "Cultivators below Body Integration need food to sustain bodily functions, but at Body Integration, Source Qi can already substitute for nourishment." Xu Xinyao burst into a giggle. Glancing at Xu Yuan's slightly smug tone, she tapped the rim of a porcelain plate with her bamboo chopsticks. "Third Brother, the real reason you're not eating is because of the Source Qi contained in the demonic beast meat and spiritual greens, isn't it?" Xu Yuan fell silent for a moment, then nodded rather helplessly, glancing down at his own palm. "My body can't digest these ingredients right now." The ingredients kept in the inner courtyard's kitchen were all premium spiritual foods meticulously selected by servants. While the Source Qi contained within could not compare to breakthrough pills, they had the virtue of being harmless to the body, and regular consumption could strengthen the physique of even a mortal. The problem was that Xu Yuan's current constitution was separated from ordinary cultivators by a thick barrier. One man's elixir was another man's poison. His current constitution could not absorb Source Qi at all; the black Source Qi inside him would even reject it. Small amounts could still be expelled through his cultivation method, but consuming large quantities carried the risk of qi deviation. Over this period, Xu Yuan had felt fortunate more than once that he had broken through to Body Integration in his sleep. Without the Body Integration realm, he might have been reduced to feeding on humans to survive, just as he had back in Huizhou County. Yet this was no long-term solution. With expenditure and no intake, the Source Qi within him would inevitably be drained dry one day. At that thought, Xu Yuan tapped lightly on the table, glanced at the newly carved formation patterns in the room, and asked with a hint of anticipation, "Is the formation finished?" Finished with her meal, Xu Xinyao gently set her bamboo chopsticks aside. "Only half-finished, and it requires you to test the results in person, Third Brother." Hearing this, a flicker of disappointment crossed Xu Yuan's eyes before giving way to understanding. Developing an entirely new formation was typically measured in years. For Xu Xinyao to have cobbled something together within two months was already no small feat. Just as the thought crossed his mind, Xu Yuan suddenly felt the surrounding light dim abruptly. Looking up, he saw that a faint mist had drifted into the room at some point. White and deceptively thin, it blocked light with remarkable intensity. Xu Xinyao sat barely a meter across from him, yet her slender figure had already vanished from sight. Xu Yuan's brows instinctively furrowed at the sudden change, but an instinctive sense of affinity felt by his body immediately made him realize that this was the "half-finished" formation Xu Xinyao had mentioned. "Brother, try breathing in this mist and see if you can cultivate with it." Xu Xinyao's voice drifted through the fog. She was operating the formation. Seeing this, Xu Yuan did not hesitate. After a long absence, he began circulating his cultivation technique. Once the Source Qi in his body completed a full heavenly circuit, everything cloaked in the mist instantly turned crystal clear. Like a fish returning to water or a dragon to the depths, his perception seemed to merge with the fog. Yet this clarity was not visual. Instead, it was like the omniscient perspective he had experienced when moving through the Inter-Abyss in the form of an aberrant ghost—even a single speck of dust in the room could be distinctly perceived. Realizing this, Xu Yuan let his cultivation technique disperse. He ran his fingertips lightly through the white mist drifting in the room and asked softly, "How is this mist generated?" Xu Xinyao's laughing voice came from across the table. "Yin origin, life origin, and Source Qi are all formless things, but after I fused the three through the formation, this mist inexplicably formed." "No, I mean how did you achieve it? This shouldn't be a formation that could be developed in just two months, right?" "Mm..." Hearing this question, Xu Xinyao let out a hesitant hum, seemingly searching for words Xu Yuan could understand. After a while, the mist dissipated, and Xu Xinyao reappeared across the table. Resting her slender fingertips lightly upon a teacup, she said softly: "The path I initially tried would have, at most, achieved the extraction of yin origin from yin ghosts within two months. But later, Master gave me a hint, and I suddenly realized this could be tackled directly from the root." "The root?" Xu Yuan asked in mild surprise. Xu Xinyao's eyes curved in a smile as she countered, "Brother, how do you think life origin and yin origin are produced?" "..." Hearing that, Xu Yuan fell into thought. "You thought of it too, didn't you, Brother?" Xu Xinyao gently lifted the porcelain cup, swirling it in her hand as the fragrant tea rippled. "Source Qi. "No matter how unique yin ghosts and aberrant ghosts are, at the end of the day, they still need to absorb Source Qi to strengthen themselves. "Once that thought struck me, I asked Master to have a hundred yin ghosts and over a dozen aberrant ghosts brought in for live research. "Originally, I wanted to compare the difference between cultivators absorbing Source Qi and these monsters doing so. But with the aid of a specialized formation, I discovered that they are just like cultivators." At this point, an excited gleam appeared in Xu Xinyao's lovely eyes. "After refining Source Qi, they actually undergo 'qi return' as well. What's more, this 'qi' that hasn't entered a 'dantian' is completely free of impurities!" "..." Hearing this, Xu Yuan understood completely. Qi return was an academic term in cultivation. The process of directing spiritual qi, fully refined through meridians and cultivation methods, into the dantian was known as qi return. With that thought, Xu Yuan instinctively cast his gaze downward at the floor beneath his feet and asked: "In other words, those hundred yin ghosts and dozen-odd aberrant ghosts have now become the fuel for my cultivation?"