Rui arrives at the prestigious Kandrian Martial Academy entrance exam as an unassuming thirteen-year-old, instantly drawing skepticism and condescension from older, physically superior competitors who view him as a weak, black-haired anomaly. The first round unleashes the oppressive, terrifying bloodlust of elite Martial Seniors, a raw psychological trial designed to exploit evolutionary instincts and weed out those lacking absolute resolve. While hundreds of arrogant applicants collapse in primal terror, their legs turning to jelly as they flee the stage, Rui draws upon his childhood memory of surviving a near-fatal kidnapping to steel his mind, stepping forward with calm defiance to claim his pass and shock the examiners. The second round drastically escalates the physical danger, locking the remaining candidates in a massive hemisphere with a hundred lethal, fast-moving bouncing slimes while forcing them to wear weighted fluid suits that constantly shift their center of mass. Rather than relying on raw reflexes like the rest of the desperate crowd, Rui leverages his deep knowledge of fluid dynamics and classical mechanics, calculating the exact angles of reflection to predict the chaotic trajectories of the slimes. He forms a brilliant tactical alliance with the young prodigy Kane Arrancar, navigating the omnidirectional onslaught to score an astonishing nine-hundred and nine points, securing a spot in the coveted top ten. This spectacular display of analytical genius completely flips the script on the older candidates who mocked his small stature, proving that intellect can match raw physical talent. Yet, his triumph is cut short as the third round is revealed to be a brutal battle royale where his high-value badge makes him the ultimate target for every desperate competitor in the arena, forcing him to defend his life against the ruthless onslaught of Fae Dullahan. Fae, a monstrously strong sixteen-year-old wielding the devastating Outer Convergence technique, relentlessly pummels Rui, forcing him to execute a desperate, high-stakes takedown gamble. Although he is brutally knocked unconscious by her One-Inch Palm, his tactical performance throughout the trials so deeply impresses the legendary Headmaster Master Aronian that he is granted a miraculous admission. This shocking reversal sets the stage for his entry into the academy, but his journey has only just begun as he must now survive the cutthroat hierarchy of the student body.

Entering the academy as a novice, Rui is subjected to the grueling physical and performative trials of the Foundation Stage, where his extreme work ethic quickly earns him a reputation as an absolute training demon among both peers and instructors. While normal teenagers require extensive sleep to recover from the crushing fatigue of physical conditioning, Rui exploits his unique physiological anomaly, consuming multiple mental rejuvenation potions successively without experiencing any psychological backlash. This allows him to train for over twenty hours a day, effectively condensing years of physical conditioning into a mere five months, a feat that defies the established medical models of the academy. Despite his rapid physical growth, Rui faces a critical existential crisis during the subsequent Exploration Stage as he struggles to discover his Martial Path, finding the standard, specialized techniques in the library to be intellectually unfulfilling and stagnant. The breakthrough arrives not through physical sparring, but during a feverish dream of his past life's greatest failure, the aborted Project Water and the incomplete Variable Objective Inverse Deduction algorithm. He realizes that his true Martial Path is not to specialize, but to integrate his scientific research into a fluid, adaptive combat style that can evolve to counter any opponent in real-time by reading center of gravity, range, and breath. This profound epiphany of adaptive evolution triggers a soul-shaking breakthrough, instantly elevating him to the rank of Martial Apprentice and shocking his instructors, who have never witnessed a novice master their path through pure, logical deduction. Armed with his newly realized VOID path, Rui enters the Apprentice library, eager to select advanced techniques that will serve as the building blocks for his revolutionary combat style. However, his rapid rise draws the attention of the academy's elite geniuses, who are eager to test the limits of this unprecedented, self-taught prodigy in the upcoming sparring trials, threatening to derail his momentum before he can even solidify his foundations.

The Apprentice sparring arena becomes a crucible of intense rivalry as Rui tests his newly acquired techniques, Collision Optimization and Damage Mitigation, against the academy's established prodigies. He witnesses a thrilling, brutal duel between the feral, beast-raised topper Nel and the skilled wrestler Felix, where Nel showcases terrifying physical attributes by shrugging off a devastating, high-impact German suplex to instantly incapacitate his opponent with a single, lightning-fast strike. This display of raw, monstrous power highlights the massive physical gap that Rui must close, prompting him to push his tactical application and physical conditioning to their absolute limits. During the high-stakes group spars, Rui engages in a chess-like battle with the elite stamina specialist Milliana, using his VOID algorithm to analyze her weight distribution, range, and subtle muscle twitches to predict her strikes before they even manifest. By executing a flawless, highly optimized counter-offensive strategy, Rui secures a stunning victory over Milliana, proving to the skeptical onlookers that his adaptive, scientific style is a force to be reckoned with. His success sparks a fierce, cyclic rivalry between his close friend Kane Arrancar and the icy Fae Dullahan, who constantly rejuvenate themselves with high-grade potions to trade brutal defeats in a petty display of familial pride. To further refine his combat arsenal, Rui dives back into the library to master complex techniques like Mirage Dive and Helical Breathing, preparing himself for the ultimate test of his first academic year. He coordinates a daring, high-level tactical plan with Kane during a special exhibition match against the formidable Martial Squire Kyrie, aiming to achieve the impossible by forcing a vastly superior officer to exert her true power. The resulting clash pushes both boys to the brink of physical collapse, leaving them unconscious in the medical wing but earning them the profound respect of the entire academy leadership.

Having completed his first full year of intense training and earned his learner's license, Rui transitions from the safe, controlled environment of the academy to the unpredictable and lethal reality of the open market. He browses the Martial Union's mission board, carefully evaluating the different classes of commissions, ranging from domestic hunting tasks to high-stakes defense operations. Seeking to test his adaptive VOID style in a real-world scenario, he accepts a low-grade bodyguard mission to protect Bella Hier, the daughter of a wealthy merchant who has suddenly become the target of ruthless syndicates following her father's mysterious death. Armed with standard Union gear, including a concealing mask and specialized uniform, Rui steps into the chaotic streets of Hajin, immediately realizing that real-world combat lacks the safety nets of the academy rings. He is forced to make split-second executive decisions under pressure, refusing to protect Bella's slow-moving attendant to ensure they can escape the hostile district before the enemy forces can coordinate a massive blockade. As they navigate the dangerous, narrow alleys of the city, Rui detects the presence of highly organized, armed mercenaries sent by the ruthless Feron Lowminer to capture Bella at all costs. This tense pursuit forces Rui to constantly run the VOID algorithm under extreme psychological pressure, knowing that a single miscalculation will result in their immediate demise. He must utilize his mastery of Balance Direction and Collision Optimization to protect his client while neutralizing the incoming threats in brutal close-quarters encounters. With the enemy closing in from all sides and the shadows of the city hiding lethal traps, Rui prepares to unleash the full, unbridled power of his adaptive martial arts in a desperate bid for survival, marking his true descent into the savage and unforgiving world of Gaea.