/* "This story draws inspiration from the 'system' in Solo Leveling while taking place in the Fate/Extella Link universe. The narrative follows the structure of Fate/Grand Order's Singularities as its setting." */

Happy Reading!

The underground chamber was dimly lit, illuminated only by the flickering glow of a few scattered torches. The air was thick with the scent of stone and steel, a quiet yet heavy reminder of the war still raging above. It was a rare moment of stillness, a fragile calm before the storm.

Ren stood near the edge of the chamber, his back against the cold wall. His eyes were fixed on the distant torches, though his mind was elsewhere—turning over the events that had led him here, into the ranks of the Vanguard. He was still processing it all. SERAPH, the Moon Cell, Karl's invasion, and now, this mission to rescue Jeanne and her group, the lost members of the Vanguard. Their fate was still uncertain, but if there was a chance to bring them back, he had to take it.

A sigh left his lips as he flexed his fingers, rolling his shoulders. This wasn't like the heists he once led. The stakes here were far greater, and failure meant more than just retreating into the shadows. He had always carried responsibility before—leading the Phantom Thieves, guiding those who put their faith in him—but here, it felt different. He wasn't just fighting against injustice. He was fighting for survival, for people who had already lost so much.

Footsteps echoed against the stone as Charlemagne approached, his usual grin somewhat subdued. "So, partner, how are you holding up?" His voice was light, but there was an undertone of genuine concern.

Ren exhaled softly, crossing his arms. "I'd say I'm fine, but that'd be a lie."

Charlemagne chuckled, leaning against a nearby column. "Honest answer. I like that. You've been thrown into a battlefield with no warning, yet here you are." He gave Ren a sideways glance. "Not bad for a rookie."

Ren smirked faintly at that but didn't reply. He knew Charlemagne meant well, but there was still a lot to prove. Before he could dwell on it further, two more figures approached—the gunman and the brawler. Unlike Charlemagne, they hadn't been as openly friendly, but they hadn't been hostile either. They were simply watching, evaluating.

The gunman adjusted his hat slightly as he leaned against a crate. "Gotta admit, kid, you're handling yourself better than expected." His sharp eyes assessed Ren with an unreadable expression. "Most people in your position would've turned tail or gotten themselves killed already."

The brawler folded his arms, casting a long shadow in the dim torchlight. "Hmph. Doesn't mean much yet. He hasn't fought with us." His voice was rough, skeptical—testing. "Talk is cheap. When the battle starts, we'll see if you're worth trusting."

Ren met the brawler's gaze without flinching. He understood the weight behind those words. Trust wasn't given—it had to be earned. It reminded him of his early days in LeBlanc, how Sojiro had once watched him with that same guarded skepticism. It had taken time to prove himself then, and it would take time now.

Charlemagne clapped his hands together, breaking the tension. "Well, that's why we're here, isn't it? To see how well we work together before we dive into the real fight." He turned toward the gunman and brawler with a knowing look. "But this one's not their fight. It's ours."

The gunman exhaled through his nose, shifting his weight. "Yeah, yeah. We know. Doesn't mean we can't make sure you two aren't walking into a death trap."

The brawler grunted in agreement. "Especially him." He jerked his chin toward Ren. "You're the one going in alone, right?"

Ren nodded. "That's the plan. I infiltrate, find Jeanne and the others, and signal Charlemagne to move in when the time's right."

The brawler scoffed. "Bold. You sure you can handle that?"

Ren didn't hesitate. "I don't have a choice."

The gunman clicked his tongue, his expression unreadable. "He's got guts, I'll give him that."

Charlemagne grinned. "That's why he's my partner."

There was a pause, then the brawler let out a low chuckle. "Fine. Just don't get yourself killed."

The gunman tipped his hat slightly. "And don't screw up."

Ren nodded. He could feel it—their words weren't quite approval, but they weren't dismissal either. They were starting to acknowledge him, even if just a little.

A set of lighter footsteps approached, and Rin stepped into view. She crossed her arms, her sharp gaze shifting between Ren and Charlemagne. "This mission isn't just about proving yourselves." Her voice was firm, carrying the weight of leadership. "Jeanne and the others are depending on you. If we lose them, we lose what's left of the Vanguard."

Ren met her gaze, feeling the weight of the responsibility settle over him. Rin didn't fully trust him yet—he knew that. But the fact that she was sending him meant that she was willing to take a chance. That alone spoke volumes.

She reached into her pocket and pulled out a small, faintly glowing gem. "Take this." She handed it to Ren, her tone serious. "It's a Code Cast similar to what we're using at Astolfo. Once activated, it'll deploy a magical field that briefly disrupts Karl's surveillance in the area. That means you can take down a target or extract someone without triggering an immediate alert—at least for a short time."

Ren turned the gem over in his fingers, feeling a faint pulse of mana within. "How does it work?"

"The gem is pre-loaded with a burst of high-density mana," Rin explained. "When crushed, it releases a temporary interference field that scrambles Karl's detection systems. He won't immediately notice a missing unit or a sudden fight breaking out. But the effect is short-lived—maybe a minute or two at best. Once it fades, he'll start piecing together that something's wrong."

Charlemagne let out a low whistle. "So, a magical smokescreen. Enough to get in, do the job, and get out before the alarm rings."

Rin nodded. "Exactly. But you only get one shot. If you waste it, Karl will notice the moment you make a move."

Ren clenched the gem in his palm, feeling the weight of its importance. "Understood."

She sighed, running a hand through her hair. "Look, I won't sugarcoat it. The odds aren't in your favor. But you two are our best shot at pulling this off."

Charlemagne gave a confident smirk. "You wound me, Miss Tohsaka. It's almost like you doubt me."

Rin shot him a flat look. "I don't doubt your skill. I doubt your ability to stay serious."

Ren exhaled through his nose, suppressing a small smirk of his own. Despite everything, Charlemagne's energy was oddly reassuring.

Rin turned back to Ren, her expression serious once more. "Just… don't take unnecessary risks. We need results, not reckless heroics."

Ren nodded. "Understood."

She lingered for a moment longer, then glanced toward the gunman and the brawler. "You two might not trust him yet, but for now, you have to. If we start doubting each other, we've already lost."

The gunman adjusted his hat again, glancing at Ren. "Hmph. We'll see."

The brawler folded his arms but didn't argue. Still, there was something less rigid in his posture now, as if the walls between them weren't quite as high.

Rin inhaled, casting one last glance at them both. Despite her strict words, she wasn't sending them off with indifference. There was something else—something unspoken in the way she looked at them. She wasn't just giving them a mission. She was putting her faith in them, however reluctantly. And that meant something.

Charlemagne clapped a hand on Ren's shoulder. "Well then, I guess that's our cue. Time to go play hero."

Ren took a final breath before following, the weight of the mission pressing down on him. No room for hesitation. If he wanted to prove himself—to the Vanguard, to SERAPH, and to himself—he had to be ready for whatever lay ahead.

No matter what it took.

The underground base's dim lighting flickered behind them as Ren and Charlemagne stepped into the open. The war-torn ruins of Fuyuki stretched before them—crumbling buildings, twisted metal, and the distant hum of Karl's patrols. A cold wind swept through the streets, carrying the scent of scorched earth. The only sources of light were the eerie blue glow of surveillance drones scanning the area and the occasional flicker of fire from collapsed structures.

Ren instinctively stuck to the shadows, his movements precise and controlled. Even without his Phantom Thief attire, he embodied stealth itself, slipping between cover like a ghost. Charlemagne followed, his usual flamboyance subdued, though a quiet confidence still radiated from him. His footfalls were light, not as soundless as Ren's, but impressively fluid for a knight.

They moved in tandem, navigating through the ruins with careful steps. Ren would signal with a subtle hand motion, and Charlemagne followed without question. A slight nod from Charlemagne indicated a clear path ahead, while Ren's quick glance toward a patrol meant they had to stop. Their silent coordination spoke volumes—despite their contrasting styles, they were quickly adapting to each other's presence.

Karl's mechanical soldiers patrolled in synchronized patterns. Some moved in groups, others stood as sentries on higher ground, their glowing eyes sweeping over the streets. Among them, corrupted Servants—once-proud warriors now stripped of their free will—stood as enforcers. A single misstep would bring disaster.

Ren crouched behind a collapsed wall, scanning the patrol routes. Charlemagne knelt beside him, fingers lightly tapping against the hilt of his sword, the only sign of his impatience. He muttered under his breath, "We take one wrong step, and it's game over. Any bright ideas, Partner?"

Ren analyzed the routes and pointed toward a narrow alleyway where the patrols were thinner. Charlemagne smirked and gave a quick nod. "Smart. Lead the way."

They moved swiftly but carefully. Ren took point, his steps light and measured, slipping through the ruins like a ghost. Charlemagne followed, less practiced in stealth but adapting quickly. The tension thickened as they neared their destination.

A sudden drone whirred above, casting a bright scan over the street. They froze instantly. Charlemagne's fingers twitched toward his sword, but Ren subtly raised a hand—wait. The tension stretched. The drone hovered, its scan sweeping dangerously close. Ren controlled his breathing, steady, unmoving.

After what felt like an eternity, the drone drifted on. Charlemagne let out a slow breath. "Damn. I was half a second from cutting that thing down."

Ren shot him a pointed look. "And risking the mission?"

Charlemagne grinned. "Relax, I said 'half a second.' I wouldn't actually do it… probably."

They continued forward, the ruined city growing eerily silent as they neared their target. The enemy stronghold loomed ahead—a fortified structure, heavily guarded. The air itself felt heavier, tainted by Karl's influence. A faint mechanical hum buzzed through the air, unnatural and unsettling.

Ren's sharp eyes picked out the best entry points, quickly forming a strategy. "There's an opening with the supply crates. If I slip in with the cargo, I can bypass the outer defenses."

Charlemagne nodded, crossing his arms. "And I wait outside as backup. If things go south, I cause a distraction."

Ren adjusted his gloves, gaze steady. "That's the plan. Just don't jump in too early."

Charlemagne chuckled, patting his shoulder. "I hope you're as good as you look, Partner."

Ren smirked faintly. "You'll find out soon enough."

Charlemagne sighed, watching as Ren moved, his form blending into the shadows.

As he approached the crate, footsteps echoed nearby. A guard turned unexpectedly, heading straight toward the container. Ren barely had a second to react, slipping into the shadows beside a stack of discarded supplies. The moment stretched, the guard lingering, eyes scanning the area. Ren controlled his breathing, willing himself to remain unseen.

Charlemagne, still at a distance, tensed. His fingers tapped impatiently against his sword hilt, his stance shifting slightly. He looked ready to intervene at a moment's notice, but he held back, trusting Ren's instincts.

The guard finally moved on. Without wasting another second, Ren slipped inside the cargo container just as it was sealed shut. Charlemagne exhaled slowly, watching intently as the crate was transported into the enemy base. His grip on his sword tightened.

Now, all he could do was wait for Ren's signal.

Charlemagne leaned against the cover of the wreckage, arms crossed as he muttered to himself, "You better not make me bail you out, Partner."

With that, the transport began moving, carrying Ren deeper into the enemy's stronghold.