The War Hero Is a Transmigrator
"Pffah—!"
Coffee streamed down his chin, and Lethe didn't even think to wipe it away. He simply stared through the newspaper clutched in his hands.
What the hell is this? A ceasefire? Peace talks? None of this was supposed to happen.
Weren't the demons the kind of bastards who'd scream "War! Never again—war!" until every last one of them was dead?
Something's wrong. No—something has gone completely, catastrophically wrong. Everything started unraveling the day I saved those kids. You absolute idiot. Why did you have to mix up the dates?
What, exactly, is a transmigrator? Someone who knows the future and intervenes to carve out a place for themselves—or, conversely, someone who knows what's coming and pretends not to, sidestepping trouble before it starts.
Lethe fell firmly into the former camp. If you were going to get dumped into another world, you might as well eat well and live well—otherwise, what was the point of the injustice? Intervening in major events wasn't optional. It was mandatory.
The world he'd landed in was Lucid Saga, a collectible gacha RPG. The premise was painfully ordinary: raise Heroes, fight Demon Kings.
That was it. Heroes. The keyword was Heroes. You raised them, and you fought the Demon Kings with them.
You needed a connection to the Heroes. Any connection. That was how you stacked the odds in your favor.
And whether you wanted a quiet life or a meteoric rise, you would eventually have to face the Demon Kings head-on. Fail to do so, and they would come for you instead—and turn the world into a living hell.
So when Lethe inserted himself into the event known as the "Rescue of the Future Heroes," it was the most natural decision in the world. Put them in his debt, and the dividends would pay out forever. That was the plan.
He'd received a transmigrator's perks, after all. He drew up a strategy and got to work at once. Save them, make a strong first impression—hell, maybe even become their master.
Those stories were everywhere, weren't they? Transmigrators who ended up as the Heroes' mentors.
And if you happened to save them in their hour of need? Nothing could be more perfect.
That was exactly what Lethe was aiming for when he successfully ambushed the carriage.
The problem was that, for a transmigrator, he was a little—no, a lot—sloppy.
He'd gotten the month of the Heroes' capture right. He'd just mixed up the day. The twelfth, not the twenty-first.
And so, instead of Heroes, he rescued something else entirely. And that something else just happened to be the future Demon Kings.
As for the actual Heroes? They'd already been dragged off, suffered every kind of torment, and eventually escaped on their own.
If they'd at least looked different, he might have noticed something was off the moment he freed them. They didn't.
In the end, Lethe only realized who they really were after everything was already over.
Demon Kings. Future Demon Kings. The cunning architects of evil who stood in the Heroes' path. Why the hell did they have the exact same hair colors as the Heroes? Lethe cursed the developers a hundred times over.
Now what? Kill them? But they're just demons who haven't done anything yet. I've seen every kind of horror this world has to offer, but hurting someone who bears no hostility is still hard. Killing them… yeah, no.
And if their own kind was already dragging them around like slaves—doesn't that leave room for a "what if"? Transmigrators are supposed to change fate, aren't they?
"Come with me."
"…"
"I won't hurt you. Look, not all humans are bad."
And so began the Fate Rewrite—or Rehabilitation—Project for the future Demon Kings.
Surprisingly, it wasn't difficult. Fortunately, it wasn't too late. The four girls were less Demon Kings and more like terrified puppies and kittens, bristling with wariness.
Lethe could only hope his choice would leave a moderately positive mark on the future. Maybe, just maybe, when they became Demon Kings, they'd be the ones advocating for peace with humanity.
If things went well enough, his wish might even come true—and this war story could turn into an academy slice-of-life.
"Mister. I'm hungry."
"Just a little longer, Ashu. A nice dinner's almost ready. Though, uh, about calling me 'mister'…"
"Then… Master?"
"…Sitri. Please just stick with mister. Never call me that. Especially not in front of other people."
"Big brother."
"Aigoo! My adorable little Mar. Yes—big brother is perfect. Just perfect!"
All things considered, it wasn't a bad stretch of time. Heroes would have been better, sure—but so what? They weren't Demon Kings yet. And that meant there was still every chance to change things.
One year passed. Then two. Time flowed on, and then one day—
"Kids?"
The future Demon Kings were gone. All four of them, vanished in a single instant.
It was a bittersweet relief. Twisting human necks had been their original destiny, but maybe—just maybe—that was no longer true. He'd grown attached, and right when he was wondering what to do about that…
And then, one year later, word arrived that every one of those girls had become a Demon King.
A sigh escaped him on its own. He'd chosen those children over the Heroes, hoping to rewrite fate. He'd reasoned with them, built good memories with them, dared to hope they might grow into kind-hearted demons.
"I guess fate really can't be changed."
It left a bitter taste. Some things, it seemed, simply could not be helped.
And that was when the real suffering began.
The date. The Heroes had originally been kidnapped on the twelfth of January, Imperial Year 212.
The day Lethe showed up was the twenty-first of January, Imperial Year 212.
Putting the Heroes in his debt had failed. The life where he swaggered around as their guardian and patron had flown off into the sunset.
So what options did that leave? War hero, obviously.
He already knew the broad strokes of every major event, and his own abilities were nothing to sneeze at. Going around declaring, "I'll just live peacefully and quietly, thanks," would have been the same as quitting the transmigrator gig and settling for Extra Number One in Another World.
Fighting the Demon Kings' armies. Cutting down traitorous humans. Smashing in the skulls of backstabbing elves and dwarves. Day after day of nothing but blood and death—a nightmare without end.
Until the Heroes finally stepped onto the stage in earnest, Lethe tore across every battlefield he could find.
And that was how he'd ended up here: holding a reasonably high position in the Empire.
Being held up as a war hero, in particular, was something he quietly enjoyed.
He'd worried, now and then, that he might get betrayed—cast aside by the Empire and forced into some revenge or regret arc—but thankfully, that hadn't happened.
Then the Heroes finished growing, finally appeared on the battlefield, and prepared to hunt down the Demon Kings in earnest. And the world's current shifted in a direction even Lethe had never seen coming.
"Sir Lethe. May I come in?"
A knock at the door, followed by the Academy headmaster's voice.
Lethe hastily wiped away the coffee he'd spat out, shoved the newspaper aside, and called for him to enter.
"I'm truly sorry to impose on your day off like this."
"Not at all. I'm sure you have your reasons, Headmaster."
Lethe waved both hands dismissively and quickly offered the headmaster a seat. Then he prepared a cup of tea just as quickly and set it before him.
"Thank you, Sir Lethe."
The headmaster smiled as he regarded the man sitting across from him.
A war hero who had fought the demons with everything he had for the sake of the Empire. Though he had stepped back from the front lines, he remained the Empire's famed blade—ready to return to the battlefield at any moment.
And yet he harbored no particular hunger for power, content to serve as an instructor at the Academy.
The headmaster was thoroughly fond of this man. A figure every student could look up to without reservation.
He had no doubt that one day, Lethe's name would be written into the annals of the Empire's great figures.
"I would love to chat with you at leisure, but time being what it is, allow me to get straight to the point. I trust you've heard the news—that they have proposed a ceasefire agreement and peace talks."
"I have. Them—the Four Heavenly Kings, you mean."
Not long after the Empire and the allied non-human races had sworn to fight the Demon Kings to the bitter end, several Demon Kings had suddenly banded together and forged a power base of their own.
Four beings whose true names, ages, genders, and combat strength were all shrouded in secrecy.
The astonishing part was that they advocated not for war, but for peace with humans and the other races alike.
No more fighting. From this day forward, anyone who resorted to violence would not be forgiven—even if they were fellow demons.
The other Demon Kings' response, of course, had been a collective don't make us laugh. True to their nature, they had diligently prepared for war.
And not long after, a merciless great purge began.
The four did not tolerate a single Demon King—or subordinate—who opposed them.
They crushed and pulverized every whisper of dissent so thoroughly that not even a murmur of protest remained. Utterly, brutally thorough.
More Demon Kings had died at the hands of the Four Heavenly Kings than had fallen in the entire war. That said everything.
"Those four Demon Kings have reportedly sent a confidential letter to the Empire."
"…A letter?"
Two questions surfaced in Lethe's mind, one after the other.
First: why had the four Demon Kings—the Four Heavenly Kings—suddenly sent a confidential letter?
And second: why on earth did the Academy's headmaster know about it?
"Wait a second. Don't tell me—"
The moment the thought clicked into place, Lethe arrived at the most reasonable conclusion.
"This has something to do with the Academy, doesn't it?"
As expected of a war hero, the headmaster thought, and nodded.
"As proof of their commitment to peace, those four have declared that they will personally enroll at the Imperial Academy."
"…I assume they aren't joking with the Empire. They actually said that?"
"They said they would keep their escorts to a minimum and live as ordinary students."
"After everything that's happened—what about the hostile stares the students are going to throw at them?"
"They say they'll endure that as well. If they truly want peace, it's only right, apparently."
"…"
Demon Kings really are all unhinged. Not just crazy—certifiably, spectacularly insane.
Proposing a ceasefire and peace talks is one thing. But why the hell are they coming to the Academy?
Don't tell me… is this the flow of fate?
Heroes and Demon Kings. Beings destined to collide no matter what.
The Heroes, suddenly unemployed, had ultimately decided to enroll at the Academy.
And now the four Demon Kings who had purged every warmonger were coming to the Academy as well.
I'm going to lose my mind, Lethe thought, and could only press a hand to his forehead.