The smell of sand. 　When Takano Yuto woke, he noticed it immediately. Until last night, that stone chamber had reeked only of mold and stone, but now a faint haze of dust drifted through the air. There were no windows. Where was it coming from? 　Knock. Knock. 　Someone was rapping on the door. Not once or twice. A steady, rhythmic knocking that continued without pause. 　(What is this?) 　Yuto pushed himself up on his elbows. His body felt heavy. The events from yesterday inside Nazarick—the sensation of Arbedo's fingers closing around his neck, the oppressive weight of Ainz's crimson eye sockets—lingered somewhere in his muscles as residual tension. 　The door opened. He'd locked it, yet it swung open from the other side without resistance. 　What entered was not human. Bone. Two skeletal warriors clad in armor stood silently in the room, their eye sockets glowing red, fixed on Yuto alone. 　"[serious]…Are you calling for me?" 　There was no answer. But one of the skeletons turned toward the corridor's depths. Follow, it seemed to say. 　Yuto reached for his thin blade—then stopped. Sharutia had taken it yesterday. His hands were empty. In this state, he could neither flee nor fight. 　(No choice but to go.) 　He pulled on his boots and followed the skeleton. --- 　They led him to the depths of Nazarick. 　The Sixth Floor—as they descended via an elevator-like magical mechanism, the air transformed. The stone corridor ended, and before he knew it, he'd emerged into a vast space. The ceiling soared impossibly high. Far above, magical light sources lined the expanse like an artificial sun, illuminating the entire chamber. The floor was sand. Fine, pale yellow sand filled a massive circular arena. Tiered seating rose on all sides, occupied by monsters—the undead, the grotesque, things that bore no human shape. If someone had built an ancient Roman colosseum underground, it would look like this. 　An arena, Yuto realized immediately. 　Standing at its center was a silver-haired woman. 　Sharutia Bradford. 　She wore the same outfit as yesterday—pale skin, crimson eyes, bat wings folded against her back. But now she sat perched on a railing, examining her claws with evident boredom. Genuine, profound boredom. 　The moment Yuto's feet touched the sand floor, those crimson eyes turned toward him. 　"[cold]You came. Making me wait, you—do you possess courage or merely dullness?" 　"[serious]I was summoned. If you have complaints, don't summon me." 　Sharutia's lips twitched slightly. Not quite a smile—more like confirmation of something. 　"[cold]I merely wish to see how well you can fight. That is all." 　"[serious]Can I refuse?" 　"[cold]You cannot." 　Sharutia dropped from the railing. She landed soundlessly on the sand. She carried no weapon. Her hands were bare. Though nearly 185 centimeters tall, her presence was overwhelming—not just the air, but gravity itself seemed to shift. Around this woman alone, the laws of physics bent slightly. 　He'd felt it yesterday. But today, it was closer. Heavier. 　"[serious]…Understood. No choice but to do this." 　Yuto remembered belatedly that he had no thin blade. But when Sharutia flicked her hand, a blade came flying from nowhere and embedded itself in the sand. The one she'd taken yesterday. 　He picked it up. The grip felt familiar in his palm. A small comfort. 　Kendo stance—seigan. Blade pointed at the opponent's throat. Weight balanced evenly. Eyes never wavering. 　Sharutia didn't assume any stance. Both arms hung loosely at her sides as she watched him. The way one might observe an insect. --- 　He lunged. 　Following kendo fundamentals, he closed the shortest distance. The blade's tip aimed for Sharutia's throat— 　One finger. 　Sharutia's index finger touched the blade's flat. That alone completely altered its trajectory. Yuto's body was carried along by the recoil. He crashed onto his back in the sand. 　All the air left his lungs. His vision blurred. 　Sand spread across his entire body. 　He stood up. 　"[cold]First attempt. Well, that is what I expected." 　Her voice held no emotion. She was scoring him. The score was low. 　He lunged again. This time, he changed the angle. Not straight on, but slightly from the right. Faster. As fast as possible. 　Again, one finger. This time it flicked his wrist. The blade flew into the sand. His body soared through the air. He hit the ground hard. This time he fell face-first, and sand filled his mouth. He tasted blood. His lip was split. 　He stood up. 　Third attempt. This time he moved low, retrieving the blade while spinning his body to come at Sharutia's flank. 　She grabbed him. By the scruff of his neck, with one hand. 　She slammed him into the sand floor. His back screamed. Something cracked. Not bone—probably. But his lungs ached. 　He stood up. 　"[cold]Third attempt. Tedious. You are too weak." 　She spat the words. Boredom was creeping into her voice. 　Yuto remained on his knees, breathing heavily in the sand. His mouth was full of blood. His right arm tingled slightly. His back burned like fire. 　(Too fast. I can't react.) 　He replayed all three exchanges in his mind. Where he'd been deflected, the angles of approach. Kendo forms were useless—the opponent wasn't moving at human speed, so all his calculations of distance were wrong. 　But. 　He stood up. 　On the fourth lunge, Sharutia's eyes moved slightly. A flicker of acknowledgment—still coming? Her expression was pure observation, nothing more. Yet something shifted. 　He was deflected. Thrown down. 　Fifth attempt. 　Thrown down again. This time his leg was swept and he rolled across the sand. His right knee screamed. It took longer to stand. His legs were shaking. 　Still, he retrieved the blade and assumed his stance. 　Sharutia watched silently. She said nothing. She'd been calling him weak moments ago, but after the fifth attempt, she was silent. 　"[cold]…Enough. Stand down." 　The mock battle ended with those words. --- 　When Yuto returned to his chamber, he collapsed onto the floor, still covered in sand and blood. 　He couldn't muster the will to clean himself. His right knee was beginning to swell. Blood still seeped from his lip. Somewhere in his back, a dull ache persisted. 　But his mind was still working. 　(What's the problem?) 　He replayed today's five exchanges one by one. The first lunge. The angle change on the second. The flanking maneuver on the third. All deflected. All processed before he could even read his opponent's movements. 　Kendo's concept of distance assumed a human opponent. Breathing rhythm, footwork, the direction of the gaze—all calculated within human reflex speed. Sharutia existed outside that framework entirely. 　He didn't need to abandon kendo technique. But he had to change the foundation. 　Not a blade that reads human movement, but one that adapts to speeds beyond human. Not distance, but gaps. A blade that hunts for openings. 　(I have to rebuild from the ground up.) 　As he thought this, something moved in the corridor. 　Battle maids—the six combat-specialized maids called the Pleiades—walked past. They didn't spare him a glance. As they passed his door, they looked through him like he was part of the wall. 　Three days in Nazarick. Every guardian he passed in the corridors emanated a low, constant killing intent. The only reason he wasn't erased was Ainz's orders, their attitude seemed to say. 　A soft knock. 　The door opened slightly, and a woman entered. 　She was short, with chestnut hair tied back, wearing Nazarick's maid uniform. Not a guardian, not one of the Pleiades—just a regular maid. She carried a tray with a single plate and a cup of water. 　Bread. Dark, hard-looking bread and a small portion of meat. 　The maid looked at him. She took in his blood-and-sand-covered state in a single second, then set the tray on the table. 　"[serious]You need to eat, or you'll die." 　That was all she said. Her tone was emotionless. A simple statement of fact. 　But that was everything. Not the guardians' killing intent, not Arbedo's disgust, not Sharutia's boredom. Just a single, businesslike, yet unmistakably human-directed command: eat. 　Sixus—that was the name he'd heard other maids call her yesterday. 　"[serious]…Thank you." 　Sixus was already facing the door. Whether she'd heard his gratitude was unclear. She closed the door quietly and left. 　Yuto bit into the bread. It was hard. The taste was bland. But he was hungry, so it wasn't bad. --- 　At the same moment, in Nazarick's Ninth Floor—Ainz's executive chamber—Arbedo arranged a stack of documents before him, her jet-black hair swaying. 　"[cold]Ainz-sama. I must respectfully reiterate: I see no justification for keeping that human alive." 　Arbedo's golden eyes were utterly composed. She wasn't appealing emotionally—she was laying out logic. That made it worse. 　"[cold]The emergence point of the black fog and that human's appearance coincide precisely, my lord. There is also correlation with the activity zones of Void Crow—the armed band that has repeatedly attacked surrounding villages. Coincidence seems unlikely. The human may be a spy, or perhaps bait." 　Ainz remained seated on his throne, saying nothing. His skeletal face bore no expression, but his fingers had stilled. He was listening. 　Then a subordinate undead official approached with a sealed letter. 　A report from the branch director of the Adventurers' Guild in E-Rantel—the capital of the Sorcerous Kingdom with a population of roughly ten thousand, the city Ainz had founded—was placed before Arbedo. 　She took it, scanned it, and laid it before Ainz. 　"[cold]Observe, my lord. A report from Pluton Ainzack, branch director of the E-Rantel Adventurers' Guild. An unfamiliar human was sighted near the black fog's emergence point—within Fazel's Hollow, near the Great Forest of Tob—walking toward the fog's residue." 　Fazel's Hollow. Where Yuto had been transported. That fifteen-meter-diameter circular area where grass had withered and soil had turned ash-gray. 　Arbedo's eyes narrowed. 　"[cold]The Adventurers' Guild has begun to take notice. If word of that human's existence spreads further, the situation could become far more troublesome. Now, while we still can—" 　"[serious]Wait." 　Ainz raised a hand, cutting her off. 　His voice was low. Heavy. 　Arbedo fell silent. Her golden eyes turned toward him. 　Ainz rose and walked to a shelf. He retrieved a small sealed container—a magical analysis vessel—containing silver-white metal fragments. 　"[serious]For three days, I have been analyzing the composition of that thin blade." 　Arbedo's expression shifted slightly—a rare occurrence. 　Ainz returned the container to the shelf. 　"[serious]I cross-referenced it against all Yggdrasil item databases. No match was found. Against all known metallic and magical materials of the New World—no match. The blade's composition exists in no world I know of." 　Silence fell. 　"[serious]I shall observe further. The decision to eliminate remains suspended." 　"[cold]But—" 　"[serious]Suspended, Arbedo." 　He did not repeat himself. That was enough. 　Arbedo bowed deeply. Her courtesy was flawless. But when she raised her head, her golden eyes remained as cold as before. The face of one swallowing her displeasure. 　The letter remained on the table as Arbedo withdrew. --- 　Yuto finished the bread and drank the water. 　The swelling in his right knee had diminished slightly. His back still ached. But not enough to prevent movement. 　Staring at the stone ceiling, he continued to contemplate the mock battle. 　Five times thrown down. Five times, utterly helpless. 　But five times, he'd stood up. 　That was the only thing he'd managed today. 　(It won't work. This blade won't work in this world.) 　Third-degree kendo. A source of pride. Ten years of honed technique. But by this world's standards, it wasn't even foundational—it w