Chapter 73: Chapter 73 - Using The Serum

Not long after, Zack stripped off his shirt and walked toward a sleek, state-of-the-art injection pod tucked in the corner of the lab. Unlike the crude setups used on the test subjects, Zack’s station was a fortress of precision and safety. “Prepare the injection,” he commanded, lying down in the pod and securing his limbs in the designated restraints.

The pod’s hatch closed automatically, sealing Zack inside. “Start the injection,” he ordered.

Thin needles pierced Zack’s arms, neck, and other points on his body, delivering the super-soldier serum into his bloodstream. Outside the pod, the advanced serum flowed through sterilized tubes, entering his body in controlled doses.

“Injection complete,” Ego announced.

“Activate the rays,” Zack said, his voice steady despite the sharp tingling spreading through his body.

A dazzling light filled the pod, stimulating Zack’s cells and triggering rapid division and reorganization. The pain was immediate and intense. “Ahhh!” Zack groaned, his teeth clenched. The rays gradually intensified, amplifying the serum’s effects.

“Ego,” Zack gasped, “why does this feel different?”

“Sir, your energy levels are spiking,” Ego replied urgently. “They’ve already surpassed super-soldier thresholds! Should I stop the process?”

“No!” Zack barked. “Increase the power! I can handle it!”

The rays reached maximum intensity. Zack’s vision blurred as the searing pain tore through his body, but he refused to falter. He endured, pushing past the limits of human resilience. Finally, the rays dimmed, and the pod’s systems powered down. “Serum injection complete,” Ego reported. “All body functions are stable. Brain activity is within normal parameters. Congratulations, sir—the process was a success.”

As the machine emitted a steady beep, Zack gradually regained consciousness. “Open hatch…” he murmured. The door of the injection pod responded, sliding open with a soft mechanical hiss.

A burst of white steam poured out, swirling in the cool air. As the mist dissipated, it revealed Zack’s transformed figure. His once-athletic build had been reshaped into something extraordinary. His body, now a striking shade of light copper, was lean yet powerful. Unlike Lao Gou and the others, who bulked up after their injections, Zack's muscles were perfectly proportioned, every sinew suggesting immense explosive strength. Standing at 195 centimeters now—15 taller than before—Zack stretched, flexing his fingers as if adjusting to this new form.

“This… feels incredible.” His voice carried equal parts awe and disbelief.

He stepped out of the pod, and instantly, the world seemed different. Colors were sharper, sounds crisper, and even the air felt alive. The faint chemical tang from the lab's equipment and a metallic hint of blood registered as clearly as if they’d been pointed out to him. Overhead, the whir of the ventilation fan was now unmistakable. Every detail, once mundane, was now vivid.

Testing his newfound strength, Zack grabbed a wrench from the workbench. Holding it in both hands, he applied a fraction of his strength. With a sharp screech, the solid metal twisted into a spiral. He stared at the misshapen tool, astonished. “Ego, are the scan results ready?” he asked, still inspecting the ruined wrench.

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“Sir, the serum has integrated flawlessly. Your physical capabilities have increased to over six times that of an average human—and they’re still improving,” Ego’s voice chimed from the lab’s speakers.

“Still improving?” Zack raised an eyebrow. “Isn’t the serum supposed to be a one-time boost?”

“Normally, yes,” Ego replied smoothly, “but your body has always exhibited unusual patterns of improvement. Have you forgotten that?”

Zack paused, realization dawning. “Wait… You’re saying the serum enhanced my natural growth process?”

“Precisely, sir. To put it simply, the serum has optimized your body’s adaptation mechanisms. Your improvements are now tied to external stimuli—primarily physical activity. In short, the more you train, the stronger you’ll get.”

“Like working out but on steroids?” Zack smirked.

“An apt comparison, sir,” Ego confirmed.

Zack nodded thoughtfully, slipping into his clothes from the bench. Or at least, he tried to. The shirt stretched awkwardly over his broader chest, and the pants were several inches too short. “Guess I’ll make do for now,” he muttered, rolling his eyes.

He stepped out of the lab and into the sunlight. The warm rays kissed his skin, and Zack took a deep breath. His enhanced senses picked up the earthy smell of grass and distant sounds of chirping birds. Without warning, he started running.

At first, it was a casual jog. Then, his pace picked up. Within moments, Zack was sprinting at a speed most people could only dream of. In under three minutes, he’d completed a lap around the neighborhood. “Sir, you’ve surpassed the speed of a cheetah—115 kilometers per hour!” Ego informed him.

Zack grinned, pushing himself harder. His movements blurred, leaving faint afterimages as he streaked past parked cars and startled pedestrians. He lapped the area again, this time in under two minutes. “That’s Zack, isn’t it?” Sophia’s voice drifted from the porch.

“Looks like him,” Annie replied, squinting to follow his movements with her enhanced vision.

“Has he turned into some kind of mutant?” Erza asked, returning from the steel mill just in time to witness Zack’s superhuman display.

After several laps, Zack finally slowed to a stop, his breath coming in controlled gasps. He glanced down at his shoes, the soles worn completely smooth. “What was my top speed?” he asked, his heart still hammering.

“Sir, you hit 150 kilometers per hour,” Ego reported.

Zack let out a low whistle, shaking his head in disbelief. “This is insane…” Even at rest, his heart was pounding at an ultra-high frequency, pumping blood through his enhanced organs. Everything about him had been fine-tuned—like a high-performance engine paired with equally advanced components.

“This is even better than those superhero I watched before,” Zack muttered to himself. His eyes landed on a beat-up SUV parked nearby. Curiosity sparked, he approached the vehicle. Planting his feet, he balled his fist and struck the A-pillar—a reinforced part of the car designed to withstand heavy impacts.

BANG!!!

The metal crumpled inward like tin foil, bending into a sharp V-shape. Zack examined his hand. Not even a scratch. “This is wild…” he murmured, a faint grin tugging at his lips.

With one hand, he grabbed the side of the SUV and flipped it onto its roof, the two-ton vehicle landing with a heavy thud.

“At this rate, the only thing I can’t do is fly,” he joked, brushing his hands off.

“Sir, additional scans show a 0.5-times improvement in your strength and speed,” Ego reported.

“Wait, I’ve already gotten stronger? But I only ran for, what, ten minutes?”

“Indeed, sir. The serum’s effects are remarkable. With just a short burst of exercise, your capabilities have already increased significantly.”

Zack’s mind raced. He could barely grasp the extent of his potential. A bold idea struck him.

“Ego… what if I designed a suit? Something lightweight, maybe even non-powered, that not only boosts my combat effectiveness but actively stimulates my body to keep improving. Like a nanosuit from that favorite game people love to test pc on.”

“An intriguing concept, sir,” Ego replied. “It’s theoretically feasible.”

“Perfect.” Zack’s eyes gleamed with determination. “Let’s get to work.” Without wasting another second, he bolted back to the basement, his mind buzzing with ideas.