Me and God of Wibu

I tossed the black bag, which contained a ghoul named Rize Kamishiro, into the trunk of the car. A dull thump echoed, and the car shook slightly as the weight settled. Tanjiro stepped out of the building, now dressed in modern clothes that matched the current era.

He hesitated as he approached the car, his hand resting lightly on the door. "Are you sure it's okay to keep her alive?" he asked, his tone cautious. "She's dangerous, isn't she?"

I nodded, leaning against the side of the car. "She's weak right now. Probably hasn't eaten in days. Whoever is keeping her alive is only feeding her enough to sustain her. She's not a big threat at the moment."

Tanjiro's brow furrowed, but he didn't press further. With a soft sigh, he opened the car door and slid into the back seat, carefully tucking his sword between the seats to hide it. In this age, openly carrying a weapon could attract more trouble than it was worth.

I started the car and adjusted the rear-view mirror, catching a glimpse of him. He sat silently, his hands resting on his knees, his expression thoughtful.

"Tanjiro," I began, breaking the silence. "Let me properly introduce myself. My name is Sakura Matou, and I'm the temporary guardian of this world."

Tanjiro's gaze lifted, his head tilting slightly in acknowledgment.

"To better understand the threats we're dealing with," I continued, "you need to know how I classify them. There are two parts: level and number."

He leaned forward slightly, listening intently.

"Threat levels are ranked from E to S," I explained. "E means it's as strong as a normal adult. D can handle ten armed soldiers. C can wipe out a city. B threatens entire countries. A could destroy a planet. S… well, S is a threat to the universe itself. Then there's SS, which is unknown."

Tanjiro's eyes widened slightly. "That's… a huge range. And the numbers?"

"The numbers are a multiplier," I said, glancing at him through the mirror. "For example, the woman in the trunk is a D1. That means she's as dangerous as 10 armed soldiers. You, Tanjiro, are currently an E8."

His lips pressed into a thin line. "I see."

I chuckled softly. "Don't feel bad. These rankings can change. Take Muzan, for example. At his baseline, he's a C2—capable of destroying two cities. But if he uses his full power, he's closer to a C8 or even a C9. Over time, he could reach B1, but he'll never break into A."

"Why not?" Tanjiro asked, his curiosity piqued.

"Origins matter," I said simply. "Muzan's just a human who gained his abilities through funny accidence. That limits him."

Tanjiro nodded slowly. "Then… what kind of creature reaches A level?"

"Beings from advanced civilizations, or sometimes ancient entities tied to the Earth," I replied. "There's one such creature nesting on an isolated island. Don't worry—it's not causing trouble for now."

"And S-level threats?" he asked, his voice quiet.

"Gods, interstellar beasts, or entities from dark dimensions," I said. "But those are incredibly rare. You're unlikely to encounter one."

As we talked, I pulled the car into the driveway of a modest house. I turned off the engine and stepped out. "We're here."

Tanjiro followed me to the house, pausing to take off his shoes at the door. "This is… your base?"

"Part of it," I said with a grin, leading him to the kitchen. I gestured to a heavy wooden table. "Push this aside."

He stepped forward and gave it a try, but the table didn't budge. He strained, his muscles tensing, but it was no use.

"Am I really that weak?" he muttered, slightly embarrassed.

I smirked, placing a hand on the table and sliding it aside effortlessly. "Yes, you're weak. Luck played a big part in your victory against Rize."

Tanjiro stared at me, speechless. Before he could respond, I opened the hidden hatch beneath the table and tossed the bag containing Rize into the well. Then I jumped in, motioning for him to follow.

He hesitated only for a moment before leaping in after me. As he fell, he caught a glimpse of bright light below. Moments later, he landed on a soft pile of cushions.

"This… this is incredible," he breathed, taking in the sprawling underground base. Robots worked tirelessly, constructing what seemed to be an endless series of levels.

"This base currently has 200 floors," I said. "And I'm working on an underground train system that will connect to all of Japan."

Tanjiro's jaw dropped. "This is beyond anything I've ever seen."

"Follow me," I said, leading him toward a steel-reinforced cabin. Once inside, I dumped the bag containing Rize onto the floor. She tore her way free and lunged at Tanjiro, but I quickly shut the door, locking her inside.

"Don't worry," I said as Rize's crazed attacks echoed through the steel. "She can't get out."

Tanjiro watched silently as I activated a wall screen, displaying Rize's frantic movements inside the cell. I gestured to a tray of meat being delivered to her room. "She's starving, but this will calm her down."

"That's…" Tanjiro sniffed the air, his expression tightening. "Human meat?"

"Not exactly," I said. "It's 3D-printed meat. No humans were harmed."

His tension eased slightly, though he remained wary. "You've put a lot of thought into this."

"I have to," I said, meeting his gaze. "I'm here to protect this world, Tanjiro. And I need your help to do it."

After a moment of silence, he nodded. "I'll help. But if I find out you're lying…"

I smiled faintly. "If that day comes, you're welcome to kill me."

Tanjiro's serious expression softened slightly, though a glint of determination remained in his eyes. He folded his arms, glancing once more at the screen showing Rize, who was tearing the artifact meat into many pieces.

"What happens to her now?" Tanjiro asked.

"For now, she stays here," I replied. "I'll monitor her behavior and decide whether she's worth rehabilitating or not."

"Rehabilitating?" Tanjiro's brow furrowed. "You believe someone like her can change?"

"It depends," I admitted, leaning against the console. "Ghouls like her are driven by hunger and nature, not malice. If we can find a sustainable way to satisfy that hunger without harming others, there might be hope for her." I trailed off, letting the implication hang in the air.

Tanjiro's lips tightened, but he didn't argue. He'd seen enough in his own world to know that some facts were unavoidable. Still, his compassion wouldn't allow him to give up easily. Just like when he protected his demonized sister.

"I'll help if I can," he said quietly. "If there's a chance to save her, I want to try."

I smiled faintly. "I expected nothing less from you, Tanjiro Kamado."

Turning away from the screen, I led him out of the cabin and into a sprawling corridor. The hum of machinery echoed around us as we passed rows of storage units, training rooms, and research labs.

"This base is more than just a containment facility," I explained. "It's also a training ground. If you're going to fight alongside me, you'll need to adapt to this world's technology and its threats."

Tanjiro's gaze darted around, taking in the advanced equipment and bustling activity. "What kind of training?"

"Combat simulations, tactical analysis, and, most importantly, learning how to identify and neutralize threats without unnecessary casualties," I said. "Your instincts are good, but you're still relying too much on raw power and intuition. Against foes in this era, that won't always be enough."

He nodded, his determination unwavering. "I understand. When do we start?"

"Right now," I said, stopping in front of a large, reinforced door. It slid open with a hiss, revealing a vast room filled with holographic projectors and automated drones.

"This is the simulation chamber," I said, stepping inside. "Here, we can recreate any environment and opponent you might face. It's the safest way to test your skills and improve without risking your life."

Tanjiro stepped inside, his eyes wide with wonder. The room seemed to stretch endlessly, its walls lined with gleaming panels that pulsed with energy.

"Let's start with something simple," I said, activating the console. The room shifted around us, transforming into a dense forest bathed in moonlight. The air grew cooler, and the sound of rustling leaves filled the space.

A humanoid figure emerged from the shadows, its glowing red eyes locking onto Tanjiro. It raised the gun and shot at Tanjiro. Swiftly, Tanjiro dodged the bullet.

"This is an E9 threat, modern soldier," I said. "Equal to your current level. Let's see how you handle it."

Tanjiro didn't hesitate. He drew his sword in a fluid motion, his stance steady and focused. The soldier switched to the knife and lunged at him, and he met it head-on, his blade flashing as he struck. The simulation adjusted dynamically, forcing him to adapt to the soldier's speed and strength.

As they fought, I observed from the control panel, analyzing his movements. His technique was impressive, but I could see areas where he could improve—his timing, his footwork, his ability to anticipate the enemy's next move.

After a few minutes, the soldier dissolved into particles, and the forest faded away. Tanjiro stood in the center of the room, breathing heavily but victorious.

"Not bad," I said, walking over to him. "But you're still too reactive. You need to learn to control the battle, not just respond to it."

He nodded, wiping sweat from his brow. "I'll work on it. What's next?"

I smirked. "You're eager. Good. But don't push yourself too hard. Rest for now, and we'll pick up tomorrow. There's a lot to cover, and I want you at your best."

Tanjiro's determination didn't waver, but he gave a small nod of agreement. "Thank you, Sakura. For everything."

"Don't thank me yet," I said with a grin. "We've only just begun."

"Beside"

I took out a book from my clothes.

"Learn this. This kind of technique can help you defeat Muzan more easily."

"Hamon."

"Yes, Hamon. This is a technique using sun energy. Similar to your breath technique but it's more advanced."