The sun was bright overhead, the sand irritatingly warm beneath him, and Luceris had one pressing problem.
He was naked.
Well, not completely. His new merman body had done him the courtesy of coming with scales below the waist, but now that his tail had transformed into legs, he was decidedly lacking in clothing.
"This is fine," he muttered to himself, trying to sound calm. "I'm a genius. I've built interstellar mechas with duct tape and caffeine. I can handle one minor wardrobe malfunction."
Spotting a nearby palm-like tree, he yanked down one of its absurdly large leaves and gave it an appraising look. With some strategic wrapping, knotting, and more muttering, he managed to fashion something that resembled a toga made by a drunk gardener.
He eyed his handiwork in the reflection of a puddle. "Not bad. Not great either. But hey—tropical chic."
Satisfied enough not to terrify locals with his indecency, Luceris brushed sand from his ridiculous outfit and set off. His legs wobbled dangerously at first, but after several graceless stumbles, he managed something resembling a walk.
It didn't take long before he heard voices. Curious, he followed the sound until the trees parted into a small lagoon.
There, half in the shallows and half lounging on rocks, sat a group of mermen and mermaids. Their scales shimmered in a range of colors, and like him, they wore large leaves knotted clumsily around their torsos.
Luceris blinked. "Oh. So the salad-wrap fashion trend is a cultural thing. Good to know I'm not just insane."
The group was clustered around a large stone platter piled high with freshly caught fish. Freshly caught—and very much uncooked.
He watched in fascinated horror as one mermaid picked up a wriggling silver fish, bit its head clean off, and chewed with visible delight.
Luceris's stomach lurched. "…Sashimi. Extra fresh. Right. Fantastic."
Still, if he was going to figure out what nightmare world he'd landed in, these people were his first lead. Straightening his leafy garment, Luceris strode confidently toward them, plastering on the brightest smile in his arsenal.
"Hello, fellow aquatic fashion models!" he announced.
The group froze, mid-bite. Dozens of golden, green, and silver eyes turned toward him. Some blinked in recognition, others frowned in suspicion.
"…Luceris?" one older merman said uncertainly. "You finally crawled out of your cave?"
Luceris tilted his head. Oh great. This body had acquaintances. I have no idea who they are, but they know me. Fantastic.
Time to bluff. He beamed wider. "Yes, it's me! Luceris… in the flesh. Or, uh, in the scales. Long time no see, right? Hahaha."
A few exchanged glances. One young mermaid whispered, "He seems… different."
Another muttered, "Less grumpy. More… sparkly?"
Luceris decided that was a compliment.
He plopped himself down on a flat rock near them, folding his legs with exaggerated grace. "So, friends, what's for lunch? Ah, raw fish, I see. A classic. Very… primal."
A merman offered him one, scales still glistening.
Luceris froze. The fish twitched weakly in his hand. Its glassy eyes stared at him accusingly.
"Ahaha… delicious, I'm sure, but unfortunately, I'm on a—uh—special diet! Doctor's orders." He set it down quickly. "But please, enjoy on my behalf."
The group shrugged and continued munching happily, while Luceris forced himself not to gag at the squelching sounds.
"By the way," he began casually, "where exactly is this fine establishment? Lovely lagoon, great ambiance. Just curious where I… we… live."
A younger merfolk, no older than fifteen by appearance, perked up. "You're in the Demon Realm, of course!"
Luceris blinked. "…Excuse me?"
The boy nodded enthusiastically. "The Demon Realm! Didn't you know?"
Luceris forced a laugh. "Oh, I knew, I knew. Just… testing you. See? You passed!"
Internally, his thoughts were a screaming mess. Demon Realm? DEMON Realm?! Did I seriously transmigrate straight into a discount underworld?
"So," he tried again, leaning forward with interest, "tell me more about this Demon Realm of ours. How's the, ah, economy? The nightlife? The democracy?"
The group laughed bitterly. "Democracy?" one scoffed. "We're lucky to survive lunch without getting caught in a raid."
Luceris blinked. "A raid? On lunch?"
The young merfolk piped up again, voice earnest. "There's no Demon King right now, so everyone's fighting. It's terrible. Every day some lord attacks another. Whole villages get burned. Sometimes we can't even fish safely."
Luceris frowned. "No Demon King? Isn't that, like, the one job requirement for a place called the Demon Realm?"
The boy nodded sadly. "It used to be better, but now it's chaos. There are two really strong lords—everyone says they're the strongest in the realm. The Vampire Lord and the Dark Elf Lord. Because of them, nobody else can rise up, but neither can beat the other. So the wars go on and on."
Another mermaid added, "And then you've got the smaller lords—imps, demon beasts, lycans, succubi, werebeasts—they fight for scraps, tearing the realm apart. We're stuck in the middle."
Luceris's brows arched higher with every word. Vampires? Dark elves? Succubi? What is this, a gothic theme park?
Still, the picture was clear: the so-called Demon Realm was unstable, fragmented, and desperate. The people lived day to day, waiting for the next disaster.
Luceris tapped his chin thoughtfully. "So… no stable government. No centralized power. Frequent wars. Daily suffering. Hm."
The young boy nodded miserably. "It's hopeless."
But Luceris's golden eyes lit with an altogether different emotion.
Hopeless? For them, maybe. But for him…
Oh, this is perfect.
The corners of his lips curled. In his past life, he had been the unrivaled genius of mecha engineering, his mind sharper than any blade. And now, transplanted into a body humming with new power, he could feel it—raw, unrestrained energy coursing through him.
Back in the interstellar world, he had SSS-ranked mental power: the ability to fold space, crush simulations, outmaneuver any opponent before they blinked. That alone made him untouchable.
But this new body came with something else: hydro affinity. Not just ordinary magic—no, this was S-rank elemental control. The water itself obeyed his will, trembling at his fingertips, promising untold destruction and beauty alike.
Luceris's grin widened into something feral. "So… no king, huh? Just chaos?"
The boy nodded again, looking gloomy. "Yeah. We're doomed."
Luceris leaned back, laughing softly. "No, kid. You're saved."
The merfolk blinked. "Huh?"
Golden eyes gleamed, sharp as the sun. Luceris stood, his leafy makeshift toga fluttering dramatically in the breeze.
"Because congratulations, everyone—you're looking at your brand-new Demon King."
The lagoon went dead silent.
Then one merman dropped his half-eaten fish. "…What?"
Luceris spread his arms wide, as if presenting himself to an adoring crowd. "It's obvious, isn't it? You're suffering. You're desperate. You need someone brilliant, ruthless, dazzlingly handsome, and slightly unhinged to bring order. Lucky for you, I tick all the boxes!"
The merfolk exchanged baffled glances.
"…Is he serious?" a mermaid whispered.
"He's… definitely sparkly," another admitted.
Luceris ignored their doubt entirely. He stared at the horizon, eyes blazing with manic determination.
Vampire Lord. Dark Elf Lord. Imps, beasts, succubi, lycans—come one, come all. This realm doesn't know it yet, but I'm about to flip the board. In one day, I'll unify the Demon Realm. And after that? A scientific revolution.