Not Just Physical Strength
Resentment—what is it? Some call it the intense consciousness of the human mind focused like a drill on a single point. Others say it's a phenomenon where excessive fixation on one emotion manifests into reality. The common thread in both theories is that the human spirit concentrates like a spike, piercing the barrier between the mental world and reality to emerge into the physical plane.
"I'm screwed...."
The black energy pouring from Kim Sung-tae's body right now was one such form of resentment. His heart was currently shrouded in profound darkness. A cocktail of utter frustration at the impossibility of success no matter what he tried, mixed with anxiety over a future devoid of hope. The result had transformed into pure, unrelenting despair and descended upon the world.
"I thought coming to this isekai would be fun. But I'm too strong. At this rate, I can't even get a girlfriend. I can't do anything...."
"Guh! What the hell is this power?!"
Normally, for resentment to manifest into reality, a person had to endure unimaginable mental torment—like being tortured to death or struck with fear so intense their mind went blank. But this was a lower dimension. Sung-tae transcended the isekai's average not just in body, but in the very waves his spirit emitted.
"It's finally weakened a bit, but I still can't take it off. Can't even enjoy my happy time. If I could at least do it solo... Nah. What's the point of solo? The moment I try that shit(?), everything around me would get wrecked. And if I actually fired(?), who knows—some random nobody might take it to the face and die. Heh. Does that mean every time I bust one, someone's life snuffs out?"
"My body's so heavy... My soul's syncing with his despair."
"Ughhh...."
The defining trait of resentment was its contagious emotion. The Demon Kings, exposed to this black resentment, were barely resisting but gradually succumbing to despair. If they were ordinary people instead of Demon Kings, they'd have collapsed like Sung-tae the instant it hit, mumbling the same crap.
"I should've just stayed on Earth. At least there was the internet—I could pick whatever I wanted, whatever my taste. But here? What the hell is this place? Nothing but dudes everywhere. No succubi in sight. Just stinking guys... This ain't the army or something... Even the army has female officers...."
"Ugh... My strength... It's fading... I wanna lie down...."
"Why did I even fight all this time...? It's all pointless...."
"Blood...? What am I, a kid...? Blood...? Why was I so obsessed with blood...?"
The Demon Kings, each regretting their past actions, were denying their very identities—the core of their existence. Amid this, only Demitrian, strolling unscathed through the resentment, let out a sigh.
"Pathetic, all of you. Demon Kings, swayed by someone else's resentment."
He scooped up a handful of the resentment. It dripped from his fingers like sticky liquid.
Resentment this dense... He'd seen human resentment before, but nothing like this.
Even the hero's wasn't this potent.
A youthful mistake. The hero he'd fought back then was truly strong; victory had been pure luck. That hero had been desperate, pouring out resentment to the end, worrying for his loved ones even in death.
"Well, the nature's totally different, but resentment's resentment."
"Why even become a Demon King, then? Shouldn't there be hot, young demon babes? But nah—one old geezer and one werewolf. The only 'women' are skeletons and minotaurs...."
"His dark desires manifested as resentment. Fitting for one who wields the sword."
Eliminating the source would only amplify the resentment. And Demitrian had no confidence in killing Sung-tae, who possessed near-infinite life force. So there was only one way: heal the mental culprit behind it.
"I'll die a virgin...."
"A shame. Our group's lady Demon Queens were due to visit soon."
"Isekai sucks...? Huh? What'd you just say?"
In an instant, the resentment blanketing the forest and mansion vanished. Sung-tae shot upright, staring at the old butler.
"What? There are... female Demon Kings?"
"Yes. They all quit after your reply got them tangled in the uproar, though."
"Kuh... Then it's no different!"
"No? How could it not be?"
"What's different?"
"Just call them back. Once they learn it's not Ignis, but you—Kim Sung-tae—they'll return. With someone as strong as you in the group, they'll feel safe."
Demitrian adjusted his monocle—a habit in serious moments. And this invitation was a crucial decision for him, the current members, and the Demon Kings' very survival.
"Will you join our group?"
＊＊＊
"Ugh. My head's still ringing."
In a grand chamber inside the mansion—not the dining setup from before, but a round table room for discussions—a single flickering candle illuminated the Demon Kings' faces.
"Hmph. So the conclusion is he'll join our group?"
"Watch your tongue. Didn't you lose to our lord?"
"Lose? Bullshit!"
Demoniac bellowed at Garba's words, but the other Demon Kings at the table were still reeling from the resentment's aftereffects.
"I wanna lie on the floor.... Become the earth.... Become ore...."
"Ice and such... It all melts in summer... I'll live pointlessly and melt away too...."
"Snap out of it, you idiots! What the hell?!"
"Kekeke. See that? That's our lord's power."
Garba glanced at Sung-tae. She'd thought his strength was purely physical, but he was a magic prodigy too? And magic potent enough to reduce Demon Kings to that? Regrettably, being far off, she hadn't heard Sung-tae's mutterings—only Demitrian had.
"Yeah. I wanna join this group."
"What's your goal? If you think it's just a casual club, you're dead wrong. Our purpose is..."
Demoniac's red eyes gleamed in the candlelit shadows.
"To exterminate the heroes and seize the world. That's our goal."
The other Demon Kings, fresh from despair mode, perked up at "heroes"—or maybe "seize the world." Probably both.
"Exterminate humanity. Claim their lands."
"Enslave humans. Raise and manage them like livestock."
"Fight humans. Keep fighting until none remain."
All goals screamed human extinction. Why did they hate humans so much? Curious, Sung-tae asked.
"Why wipe out humans?"
"Just 'cause. Humans suck."
"Weakest things, yet the most numerous. Not even pretty. Some are okay... but not sculpture material."
"Fine by me. Endless tools to fight."
No reasoning with them. Like humans squashing ants out of blind disgust? The Demon Kings loathed humans uniformly.
"I'll explain that."
Demitrian, the only reasonable one, adjusted his monocle and spoke gravely on why Demon Kings despised humans.
"Demon Kings are beings of immense power. We've endured endless ages, observing the world. Our strength let us achieve desires, live as we wished."
"What’s that got to do with hating humans?"
"We didn't start out hating them. Some lived among them, others observed. But it always ended the same."
The windless room's candle flickered under the heavy mood.
"Touching humans directly. Observe or coexist amiably—they end up fearing our power. My observations suggest humans instinctively reject what they can't comprehend or surpasses their cognition. As humans turned hostile one by one, we discovered a new pleasure."
"What?"
"The thrill in long, meaningless lives. Conflict."
Coexisting or observing humans had limits—endless repetition. Girl becomes mother, grandmother; her grandson repeats the cycle to old age. To near-immortals like Demon Kings, it was eternally dull.
"Humans change drastically under stimulus. Wars pepper human history, yet each is unique. The desperation, despair, screams, and struggles for hope therein revealed new facets of humanity to us Demon Kings."
"Mm-hmm."
"That's why I can't quit war."
"The faces humans make turning to ice sculptures!"
So they tormented humans to escape boredom.
"Why bother? No guilt?"
"Because you're human. Tell me—observe an ant colony, step on some ants, do you apologize to them?"
Sung-tae had no answer. Squashing ants might spark brief pity, then forgotten. Most humans felt nothing.
"To us, humans are mere ants. No guilt. Though I still enjoy observing."
"Ants, huh."
Sung-tae eyed the Demon Kings, deciding they couldn't roam free. Exiled by heroes or not, they'd invade humanity again. That'd make carefree travel impossible. Heroes might stop them eventually, but not before countless deaths.
Beautiful isekai girls I haven't seen might die.
War was cruelest to the weak—elderly, kids, women hit hardest. Still dreaming of world travel, Sung-tae resolved to stop them.
"You say it's because humans are weak—like ants?"
"Obviously. Without heroes, I'd have them all as livestock—"
Demoniac shut up mid-sentence. All Demon Kings felt a chill down their spines and scattered. Unlike the prior negativity, this was inexpressible fury from Sung-tae—unprecedented even in their long lives as Demon Kings.
Amid that fury, Sung-tae glared at each one.
"Then this works too. I'm unconditionally stronger than you, so no invading the human world."
"What?! Without that weird aura, you'd be—"
"That was just venting. No attack."
Sung-tae's black armor rustled. His heartbeat terrified theirs. They'd felt no fear or defeat against multiple foes, but pre-battle tension was inevitable.
"All of you, kneel. From today, you're my subordinates."
＊＊＊
Demon King bodies always stayed in peak condition. Immune to illness or fatigue. Only heroes or fellow Demon Kings could wound them.
"What... did you say?"
Feeling an unknown power from Sung-tae, they doubted their own states. He wasn't a hero, no mana detectable—just a normal human. Why fear? To those like Demitrian who couldn't sense his life force, Sung-tae seemed an oddity using strange power.
"Deaf? You said you mess with weak humans like ants. From my view, you're the ants—so I'll do as I please."
"Arrogant fool, deluded by cheap tricks. Human scum begging to die."
"A warrior knows courage from bravado. You're no warrior—just full of bravado."
"Fine! Decided. You'll be a tombstone in my garden. A reminder of human folly."
The Demon Kings unleashed killing intent at Sung-tae—enough to shatter Garba's will instantly. But also to forget the fear he'd instilled.
Clap!
"Fight if you must, but outside. Destroy the house, and I won't forgive you."
Demitrian clapped, lightening the mood. His gloved hands smacked crisply, dissipating the intent filling the room. The Demon Kings glanced at the old butler, gesturing Sung-tae outside.
"Follow. I'll teach you your place."
"I fight first. Step back."
"Forget fighting—his hide's mine."
Sung-tae and the Demon Kings exited. Last out, Demitrian gathered mana at his fingertip, sweeping it over the house. It seeped in, flashing briefly before vanishing—a protective spell for contingencies.
"Hmm. Hope they don't hit the mansion."
He wasn't worried about the Demon Kings' attacks. Just Sung-tae's. As he stepped out, he waved lightly; the candles went out. But he lingered, staring into the dark, eyes gleaming as if searching.
"My imagination?"
Maybe age. With a click, the door shut.
Unseen even by Demitrian's eyes, a small child left alone in the dark slumped over the table, murmuring softly.
"I'm hungry...."