Manhattan Project (2)
The Manhattan Project. Though it shared no real connection with the actual place called Manhattan, it was a project that could only be seen as having left an absolute impact on humanity's fate. Born from fears during World War II that Germany might develop nuclear weapons, it bore fruit with the success of the first atomic bomb test, Trinity.
It wasn't coincidence that Jeong-jae had named the new scroll he was writing after Oppenheimer's masterpiece.
"Two people would be enough to activate it. But mana... we need to supply that massive amount of mana. Where the hell are we supposed to get that much mana?"
According to the search results from Walter and Rose, the Karmic Fire flames hadn't even killed the Gargoyle Queen. She'd escaped the castle in a hurry to the north, badly wounded but alive—that much was confirmed.
Yeah. Even the ultimate Karmic Fire magic, something no one else could replicate, had failed to decisively slaughter a single Demon King executive. With so few weapons humans could wield against the mighty demonkin, how were they supposed to turn the tide of war? How were they going to land a real blow on the Demon King?
Walter H. Hellhound was known for single-handedly eliminating dozens of mid-level Demon King officers, but there were still no confirmed kills on upper-level executives. Walter didn't fall short in raw power against them, but he lacked that decisive finishing strike. And if you failed to kill a Demon King executive, it would always return stronger, leading an army to threaten the Audrich Empire.
This vicious cycle couldn't be allowed to repeat. It couldn't repeat.
"Even pouring in all my mana, it's impossible. And I can't dial down the power either."
If the scroll Jeong-jae had devised worked as intended, the projected explosive yield would be around 150 megatons. Paired with location-tracking magic and used when high-ranking Demon King executives gathered in one spot, it would possess absolute power to wipe them all out.
That kind of force was about three times the yield of the most powerful hydrogen bomb in human history. Sure, there were spells that could cause earthquakes or typhoons, so in pure energy terms, stronger magic might exist. But no spell had ever concentrated this level of heat and explosive power into a confined space, melting everything on the surface with ultra-high temperatures.
At least, not according to Jeong-jae's research as an Earthling.
Of course, since it didn't use radioactive elements, there was no risk of fallout either. If they could just activate the scroll, they could deal a massive, clean, and certain blow to the enemy.
Due to the nature of mana circuit-style magic, 150 megatons was the minimum yield—it could be amplified, but not reduced. But the mana required even for that minimum was the real problem; there were almost no viable sources to supply it.
It was like the scientists in the Iron Man movie who'd successfully replicated arc reactor tech but were struggling because they couldn't miniaturize it.
"I'm not Tony Stark..." Jeong-jae muttered self-deprecatingly.
Of course, for spells requiring excessively large mana, there was always the option of multiple mages channeling into one scroll for joint activation. But not all spells worked that way—some did, some didn't. This was firmly in the "doesn't" category.
Activation might succeed, but if the mana purity was compromised, the spell's coordinates would randomize. Using something this devastating with scrambled targeting? That was a catastrophe. Not even worth considering.
"A way to handle this firepower with the pure mana of just one person..."
Sighing heavily toward the ceiling, Jeong-jae turned back toward the bookshelf. His eyes caught a book with an intriguing title.
"Research on Converting Life Force to Mana..."
Jeong-jae instinctively withdrew the hand he'd reached out for it. He'd been fascinated by this topic before. He'd devoured it all day, stamping his feet in frustration because he couldn't actually experiment.
The theory from that book was etched firmly in his mind. Converting lifespan to mana wasn't that hard—it was like trading longevity for a bargain-bin substitute. Even humans with low aptitude could generate massive mana this way.
But would it be enough? Could he use that theory to precisely deliver 150 megatons exactly where he wanted, without issue?
Jeong-jae wasn't suicidal. He had no intention of throwing his life away like a disposable rag for nothing. Even if something truly important was at stake, there weren't many things worth staking his life on.
"But if it's possible..."
Yeah, let's just check if it's feasible, he thought. No point dwelling if it wasn't.
He wouldn't feel at ease without crunching the exact numbers and seeing how much strain it would put on his life force.
Pulling out scroll paper and a quill, Jeong-jae deftly dipped the nib in ink and jotted down the formulas he'd memorized.
Park Jeong-jae. Age 27, height 176 cm, weight 65 kg... More precise data would be better, but this was enough for now.
Scritch, scratch, swish-swish-scratch.
Only when the nib's scraping stopped did Jeong-jae feel the pain in his writing hand. In his intense excitement, he'd gripped the quill so hard his nails were digging into his palm, threatening to draw blood.
"It's possible."
But a thrill and tremor overrode any pain, dominating his body. Cold sweat beaded on his forehead; his free hand shook uncontrollably. It was razor-thin.
If his base mana pool as a Grand Archmage had been even slightly smaller, it would have been impossible. But no matter how many times he double-checked, the pristine mana equations confirmed it: with aggressive life force conversion, he could cast this grand magic.
Mana devices? No. Cooperative casting? No. Only life force conversion—and only if the world's strongest mage poured everything in.
This... this was...
"Fucking awesome."
That was Jeong-jae's first reaction.
Power was guaranteed. The insane mana consumption alone ensured absolute destructive force.
No more Demon King forces targeting the imperial palace. No more hordes of vampires and succubi knocking on ordinary folks' doors every night, spreading terror.
If this magic worked. If they could activate the Manhattan Project when executives gathered for an advance.
"No, wait, that's insane. I'd still have to die. That's not right, is it?"
Snapping out of his excitement, Jeong-jae regained his senses and shoved the calculations away with a trembling hand.
Suddenly, it felt wrong. Too extreme. The Empire hadn't collapsed yet; the palace wasn't in flames. Why should he, an outsider Grand Archmage, sacrifice his life?
He wasn't resentful about sacrificing—he just felt his talents could be used better elsewhere. Like faithfully following Walter's orders and racking up merits as he had before.
But he couldn't erase the image from his mind. The flames. Karmic Fire devouring the castle.
He'd never intentionally aimed his magic at civilians before. Walter had implied it might happen again. Jeong-jae understood. Those who died inside were unavoidable sacrifices. Noble. Honorable.
But with the human-elf alliance visibly faltering—even to a three-year-old—how many more sacrifices would this world endure?
"We can stop it."
Jeong-jae said it aloud. He wasn't a tactical genius, but he knew the basics.
This magic wouldn't just shatter enemy leadership; timed and positioned right, it could vaporize hundreds of thousands of troops at once.
Hundreds of thousands? Child's play. Push it, and it could casually erase millions of orcs.
Earth's modern militaries wouldn't cluster millions fearing counterstrikes, but this world was different. It could uproot the Demon King's forces from the core—a trump card.
Why hesitate with this in hand? What bigger deed could he accomplish alive?
Jeong-jae's resolve stirred. Escapism from letting more innocents die in battle. Pride in leaving an indelible legacy over quitting. And as an Earthling, a lingering detachment from this world fueling a strange determination.
"Let's do it. Fuck it, just do it."
With a quavering voice, Jeong-jae picked up the scroll.
There were no structural flaws. Using duplication magic, he made a copy of "Manhattan," pocketed it, and locked the original in the safe.
This wasn't a solo spell. The massive magic circle required someone with basic knowledge to assist, ensuring it didn't warp.
For maximum efficiency, the hero party needed to herd executives into one spot.
That meant aggressive pushing, absorbing losses to force the enemy into a tight defensive perimeter.
Jeong-jae's plan: Walter launches a massive offensive, targeting all executives at once. Even upper-level ones would struggle against Hellhound's onslaught, forcing them to cluster for mutual defense.
The Empire commits fully, mobilizing all forces to envelop from multiple angles, creating maximum pressure.
It might cost tens of thousands, but success would corral vast numbers of executives and monsters.
Then, on Jeong-jae's signal, the "encircling" imperial forces withdraw en masse. Once clear of the danger zone, drop "Manhattan" on their heads before they react.
This would start the battle on enemy turf, minimizing civilian risk. Walter's all-out push would draw their full response, packing them dense for maximum evaporation.
With luck, even the Demon King himself might get caught—a jackpot. Worst case, Walter's command ensures irreparable damage.
The more he thought, the more ambitious and advantageous it seemed.
At some point, forgetting his own death, Jeong-jae pondered who to ask for the "assistant" role.
Top choice: Walter himself. But they'd grown close. Walter called him "friend" genuinely. A hero's nature might make him balk at sacrificing Jeong-jae, strategic merits aside. No need to get labeled a suicidal nut.
Jeong-jae scratched Walter off.
"If not Walter, then..."
A university student? Talented mages, sure, but kids. They might panic at the sheer scale of the circle.
Jenis's face flashed, but no—that wouldn't fly. For reasons he couldn't pinpoint, she'd hate this plan.
Then, a brilliant idea struck.
Margaret. Princess Margaret the high elf could be persuaded.
She pitied all innocents, a fairy of compassion. But she also harbored deep resentment toward mages who burned forests with fire.
She wouldn't eagerly accept his sacrifice, but with diligent explanation—for the greater good, saving countless lives—he could convince her.
Her mouth might run harsh, but Jeong-jae knew her character was noble.
Elves' mana affinity made her perfect for stabilizing the circle too.
How hadn't he thought of her first? Trusted in the hero party, she could nudge Walter toward the strategy Jeong-jae wanted.
"Perfect! I'll talk to Margaret!"
And this was exactly three hours before Jeong-jae witnessed the rare explosion of Princess Margaret's tear ducts.