I Transmigrated Into the Game as the Luckiest Extra

"Alright!" His triumphant shout echoed through the chamber, bouncing off the ancient walls. "It worked!"

Not only had the insane procedure succeeded, but he had even unlocked a historical achievement something most master Creators, even those with decades of experience, never achieved in their entire lifetimes.

"The procedure was absolutely insane, but… it came out successful. And I even got a title out of it." Kael's lips curled into a wide, unrestrained grin. "This… this could be my path forward. My way to rise above everyone else."

His mind was already racing ahead, plotting and scheming. If he played this right, his reputation would soar to legendary heights. But if he misstepped, the consequences could be catastrophic.

Kael shook his head, forcing his surging excitement down into a manageable simmer. "Hay, explanation."

Ding. "Affirmative. I am Hay, Master Kael Vi-rel's AI assistant. Beginning analysis of the procedure and object created."

The familiar, cheerful tone rang in his mind, but this time there was an uncharacteristic weight to it almost as if the AI itself understood the sheer magnitude of what had just been accomplished.

"First, the basics," Hay began, its voice crisp and clear. "What Master has done is forcibly seal a volatile, distorted piece of space inside a mundane container. The best analogy? Think of it as stuffing a raging hurricane into a teacup. As long as the teacup remains perfectly intact, the storm is quiet and contained. But the moment it cracks…"

Kael frowned, a sliver of unease cutting through his triumph. "…It bursts out?"

"Exactly!" Hay said brightly. "The isolation magic inscribed onto the box is the only thing holding that distortion stable. If the box is broken, shattered, or even carelessly opened, that containment field will vanish in a nanosecond. The distorted space will then attempt to return to its original, unstable size in an instant. That means… a violent, explosive burst of raw spatial energy, or worse, a chain reaction that tears apart the very fabric of everything in its vicinity. Imagine a balloon filled with far too much air, only the 'air' is raw space itself. Pop! Goodbye chamber. Goodbye Master."

Kael grimaced, a cold knot forming in his stomach. "You really know how to make me feel safe about my new invention."

Hay ignored the sarcasm, its tone shifting seamlessly into that of a patient lecturer speaking to a particularly gifted student.

"Now, here is where it becomes truly interesting. The box, as it is, is not just storage. It is a stage. A vessel. Whatever magic you feed into it becomes the main performer in a spectacular, and potentially lethal, play."

Kael's brows lifted, his curiosity piqued.

"For example: if you incorporate water magic into the contained space, it's like cramming an entire lake into a single wine bottle. Smash it open, and whoosh! The full volume and pressure of that lake bursts free all at once, creating a deluge capable of drowning anything nearby.

If you infuse fire magic, it's like hiding a raging, sentient bonfire inside a delicate matchbox. Break the matchbox, and a tidal wave of flames will roar out, consuming everything in a fiery vortex.

If you add healing or revitalization magic, the opposite happens. Instead of cataclysmic destruction, the box blooms with an explosion of pure recovery. Wounds close in an instant, fatigue vanishes from weary bones, and life force spreads outward like the first rays of sunlight after a long, dark storm. A single box, prepared correctly, could heal an entire army in a matter of seconds."

Kael's heart pounded faster and faster as he pictured each incredible scenario. The images played vividly in his mind's eye: entire legions of enemies consumed by an instantaneous inferno, his allies snatched from the jaws of death by a sudden wave of healing light, impenetrable fortresses crumbling under the sheer kinetic force of a space-detonated flood.

"And," Hay continued, its voice full of intellectual fervor, "this method surpasses direct spellcasting in several crucial ways. A mage must chant, focus, gather ambient energy, and then release their spell. That takes precious time. In the heat of battle, a second too slow can mean the difference between life and death. But a box like this? It is already charged. Already primed. Just break or open it instantaneous effect. It is faster, more efficient, and potentially exponentially stronger than any conventional casting."

Kael let out a low, shaky whistle. "So it's basically… weaponized, on-demand magic."

"Precisely," Hay replied. "The applications are nearly limitless. With careful preparation, you could wield this as a devastating weapon, a revolutionary tool, or an unparalleled support device. But remember this, Master: what you have created is not merely an item. It is a concept. A new category of possibility that will change the known rules of magic. In the right hands, it can save countless lives. In the wrong hands… it could erase them from existence."

Kael stood frozen, the profound weight of Hay's words settling on his shoulders like a physical cloak. He glanced at the simple wooden box on the pedestal. A moment ago, it had looked like his greatest achievement. Now, it looked like a ticking bomb.

He chuckled weakly, a humorless sound. "Great. I've made history, and now I have to worry about surviving long enough to enjoy it."

Hay's tone lightened again, a sudden burst of cheer after the heavy, existential explanation.

"Well! That concludes my explanation for today. Until next time, dear readers."

Kael blinked, his train of thought derailing. "…Readers? What readers, Hay?"

But the AI's voice faded from his mind, leaving only a profound and ringing silence.

Kael shook his head with a wry, bewildered smile. "Unbelievable. Even my AI assistant's lost its marbles."

Still, the truth was undeniable. The box was powerful. It was dangerous. It was world-changing. And he, Kael Vi-rel, was the one who had made it.

"I'll need more preparation before I can even think of using this," he muttered to himself, his gaze hardening. "A lot more. And far better resources too."

His eyes sharpened with a new, unshakeable determination.