The Demon King's History

My new official-unofficial mission was to be a decoy, and I was taking to it with the dedication of a lifelong professional. For the past two days, while Justus prepared for his grim undercover mission to the Holy Kingdom, my own mission had consisted of a grueling schedule of activities. First, a thorough, hands-on inspection of the nap-worthiness of my office sofa. This was followed by a high-stakes investigation into whether a deck of playing cards could, in fact, be used to build a structurally sound, five-story tower. The results were inconclusive but required extensive, repeated testing.

It was the best job I’d ever had.

The rest of the team, however, was ruining the atmosphere with their relentless competence. Eliza and Edgar were practically buried alive under a mountain of Marie’s intelligence documents, their low, intense muttering about financial ciphers and shipping routes a constant, annoying buzz in the background. My office no longer felt like a sanctuary; it felt like a library where I was the only one not studying for finals.

Just as my card tower reached a record-breaking sixth story, the door opened, and Princess Marie walked in, carrying a large, ancient-looking book bound in cracked, black leather. It looked heavy. It looked important. It looked like work.

“I was in the restricted section of the Royal Archives,” she announced, placing the dusty tome on the one small, evidence-free corner of my desk. “I believe I found something relevant.”

Eliza looked up, her eyes sharp. “Does it pertain to Alistair’s finances?”

“No,” Marie said, her expression serious. “It pertains to his motivation. If we are to understand what the Slime Dai Maō Karuto wants, we must first understand the so-called ‘glorious age’ they are so desperate to bring back.” She looked around at all of us. “We need to talk about the Demon King.”

I groaned, my card tower collapsing from the sheer psychic weight of the impending lore dump. “Oh, great. A history lesson. Is there a summary on the back? Maybe a movie adaptation I could watch instead?”

Marie ignored me, opening the book. “The public story everyone knows is a gross oversimplification. They believe the ‘Demon King’ is a singular, immortal monster. That is a lie, designed to create a simple narrative of good versus evil.”

She paused, letting the weight of her words settle. “The truth is, ‘Demon King’—or more accurately, ‘Maō’—is a title. A specific classification for a being, human or monster, that has achieved an immense level of magical power. There have been many Demon Kings throughout history. Likewise, the ‘Hero’ is also a specific class of being, one who manifests immense holy power and is almost always a summoned individual from another world.”

My blood ran cold. A summoned individual from another world? She’s talking about me.

“The last great conflict, 120 years ago, was not a simple war,” she continued. “It was the culmination of a cyclical holy war. And the Demon King at the center of it was an entity unlike any before. Their name was Rumiri Tempest.”

Wait a damn minute. Rumiri Tempest? Isn't that the guy who's reincarnated as a fucking oozes or slime or mucus, right? That's a straight-up copyright violation. This damn author is just asking for trouble. We haven't even gotten our story published yet! You can't just go around using names from other series. Come on, man, why are you doing this to me? 

“Rumiri Tempest was not a traditional Demon King bent on destruction,” Marie explained, her voice filled with a strange mix of reverence and sadness. “They were a reformer. A leader who sought to build something new: a grand federation of monsters, a nation where all races—goblins, orcs, lizardmen, and even humans—could coexist in peace and prosperity. This ideology was a direct threat to the bedrock belief of the Holy Kingdom: that all monsters are evil creatures to be subjugated or destroyed.”

Justus, who had been listening with a conflicted expression, finally spoke. “But… the hero of that age! The legends of his righteous struggle against the Demon King’s armies…”

“The hero of that age,” Marie said, her eyes flashing with a cold light, “was the Light Fast Hero Masayuka. A young man summoned from another world, just like our own Hero Sukebe. He was powerful, and he was idealistic. And he was tragically manipulated by the religious zealots of his time—the direct precursors to the Slime Dai Maō Karuto.”

My brain felt like it was short-circuiting. The names. The plot. It was all so familiar.

A pragmatic, nation-building Demon King named Rumiri Tempest. A summoned Japanese hero named Masayuka. A corrupt Holy Church pulling the strings. This isn’t just a revisionist history… this is a blatant, shameless, low-budget knock-off of my favorite light novel!

I could almost hear my inner monologue screaming. Author, you sly motherf...! You didn’t even file the serial numbers off! You just changed one letter in the name and called it a day! Good luck on being poor, you damn Author.

“The zealots couldn’t allow a peaceful monster nation to succeed,” Marie said, her voice dropping. “It would have shattered their power. So they painted Rumiri’s federation as a threat, a demonic empire in the making. They fueled Masayuka with propaganda, with lies, and sent him to destroy a dream of peace. The final battle wasn’t a clean victory. It was a tragedy. Masayuka, in a desperate final gambit, didn’t kill the Demon King. He used a forbidden technique to create a powerful, eternal seal, trapping Rumiri Tempest and their entire city in a suspended state between dimensions.”

“So the seal…” Eliza whispered, her analytical mind grasping the implications. “Its purpose wasn’t to contain a great evil. It was to halt a political and ideological rival.”

“Precisely,” Marie confirmed. “They couldn’t defeat Rumiri’s dream, so they put it to sleep and rewrote the history books to turn a visionary into a monster and their manipulated hero into a selfless martyr.”

The silence that followed was heavier than a mountain. Justus looked utterly broken. Eliza was furious at the scale of the historical manipulation. And I was having an existential crisis.

I hadn’t just been summoned to another world. I’d been summoned into a cheap imitation of a story I already knew. The bad guys were a cult named after a parody of the protagonist, and I was the new hero who was supposed to… what? Finish the job of the last hero and destroy the guy who was actually the good guy all along?

This was a narrative, ethical, and legal nightmare.

Then, Marie dropped the final bomb, and she dropped it right in my lap.

“The summoning ritual that brought you here, Hero Sukebe,” she said, her voice soft but heavy with meaning. “The Grand Summoning Circle in the castle. It doesn’t just pull a hero from another world. It draws its immense power from that very seal on Rumiri Tempest. The two are intrinsically, magically linked.”

And there it was. The final, damning connection.

My path to a lazy life and my potential path home were now tangled up in a century-old political scandal that was also a blatant act of plagiarism. I wasn’t just a character in a story anymore. I was a character in a bad fanfiction. And I had a sinking feeling the author was about to make things more absurd than they currently are.