In just one day, the Demon King's Castle changed hands.
The old Demon King stepped down, demoted to one of the Demon King Army's executives, while the human who stormed the castle—or in the monsters' eyes, a genuine monster—became the new Demon King.
Though the position was seized by force, it was still a major event for the demon race. At the old Demon King's suggestion, Eiji reluctantly ordered a night-long banquet throughout the castle.
This was also meant to signal to the lower-ranking monsters that everything would continue as usual, helping to stabilize morale.
But the matter wasn't over yet.
Eiji was well aware of this.
Currently, only Sylvia and Serena among the executives had sided with him.
Excluding Beldia, who abstained, and Vanir, who resigned, the stances of Hans, Wiz, and Wolbach remained unknown.
Especially with the goddess Wolbach—just from Serena's proselytizing alone, it seemed Eiji had already offended her.
As for the old Demon King and his witch daughter, their attitudes were also unclear. On the surface, they appeared to have conceded, but they still seemed to have their own schemes, making it unlikely they would submit so easily.
Eiji had seized the Demon King's throne through sheer strength.
But to hold onto that position, power alone wouldn't be enough.
Nighttime.
In the bathhouse of the Demon King's Castle.
"That brat is soaking in the bath right now. Since he's human, humans have countless weaknesses!"
Outside the bathhouse, the old Demon King spoke gravely to his daughter.
"Next, we'll pump poison into the water through the inlet. This is a special toxin I obtained from Hans. As a Deathly Poison Slime, his venom can kill anyone who touches it instantly!"
"I see!"
The witch gasped in realization. "So that's why you pretended to submit during the day—to poison him tonight!"
"Airi, you're still too young to understand the art of deception."
The old Demon King nodded approvingly. "You should learn from me. I can run to Lord Vanir and Lady Wiz every day, crying and begging until they're so annoyed they agree to become executives. That's also a skill—just throw away your pride, and it becomes incredibly convenient!"
"I understand, Father!"
Airi Yasaka nodded in sudden enlightenment.
Father and daughter worked together to pour the Deathly Poison Slime's venom into the bathhouse.
Meanwhile.
Inside the bathhouse.
"Just got here and already tangled up in trouble!"
Eiji sank most of his body into the hot water, letting out a long, satisfied sigh.
After preparing supplies in the DanMachi world, he had immediately taken leave from Finn and the others and charged into the dungeon. Ais had been quite displeased, but he managed to coax her into staying behind.
The moment he entered the dungeon, he was transported to this new world—and the first place he landed was the Demon King's Castle.
Naturally, things had unfolded this way.
"But I brought this on myself... No point dwelling on it now. Time to relax in the bath!"
Eiji let his body go limp, his mind naturally emptying.
In this state of complete relaxation, his body floated effortlessly on the water's surface.
"Y-Your Majesty?!"
A familiar, booming voice echoed from the bathhouse entrance.
Beldia rushed in, clutching his head, his face filled with shock.
"Are y-y-you alright? Did someone poison the bathwater?!"
"I'm fine."
Eiji stood up with a gloomy expression.
"Huh? But you were floating like a corpse, and I thought since you're human, you might not have much poison resistance..."
Beldia was wrapped in a towel, his neck area conspicuously empty. The face cradled against his chest was that of a square-jawed middle-aged man, his muscular build completely obscured by armor during the day.
"I was just completely relaxed, not dead."
Eiji rolled his eyes.
"Relaxed... enough to float like a corpse?"
"Don't make a fuss. Your understanding is too shallow to comprehend this."
"Oh! Oh!"
Beldia thought back to Eiji's monstrous swordsmanship earlier that day and nodded thoughtfully.
"Stop standing there. You came to bathe too, right? Then sit down."
"May I? Then pardon my intrusion!"
Beldia was puzzled but happily settled into the water, still holding his head.
This new Demon King seemed surprisingly approachable and down-to-earth.
"But, Your Majesty, why did you come to this public bath?"
"Hmm? Can't I?"
"No, of course not! As ruler of the Demon King's Castle, you can go anywhere!"
Beldia scratched his chest-face awkwardly. "But this is the communal bath. Because you're here, none of the other monsters dare enter now."
"Communal bath? There's a private bath for the Demon King?"
"Naturally! It's slightly smaller but better equipped, with stunningly beautiful demon women attending to your needs. Truly enviable—I mean, an extraordinary experience!"
Beldia's expression turned dreamy.
Demon women attendants?
Eiji's face twisted with instant regret. He'd thought any bath would do, missing such an opportunity!
"...Maybe you could visit the Demon King's bath afterward?" Beldia cautiously suggested, noticing his expression.
"Right! Who says you can only bathe once a day?"
Eiji had an epiphany. He'd been too caught up to realize!
"You're brilliant, Beldia!"
"Oh, it's nothing..."
Beldia looked at him strangely. Was it possible—just possibly—that this seemingly cool Demon King was actually a pervert?
"There's also a succubus-run establishment in the castle, meant to reward the garrison troops. Most don't know about it..."
"?! Beldia, I think you're a truly wonderful person!"
"You flatter me, Your Majesty. I can see you're no ordinary individual either!"
They exchanged glances.
Soon, the bathhouse echoed with their conspiratorial snickering.
Beldia sighed in relief. As a knight, he'd struggled with switching loyalties so abruptly that day and had come to relax. But after this exchange, he felt this new Demon King was absolutely worth serving!
He was completely won over by His Majesty's charismatic personality.
Ten minutes later.
Eiji arrived at the Demon King's private bath.
Then he saw the demon beauty lying in the bathhouse in a very suggestive pose, utterly enchanting.
So enchanting that only bones remained.
Eiji fell silent.
He understood the reasoning.
But why drag an innocent, well-proportioned demon beauty into this?
"Damn it, I didn't expect him to go to a public bathhouse! What a miscalculation!"
"What should we do now, Father?"
"Don't worry, I still have another plan!"