Became Pregnant With the Demon King’s Child

By the time they arrived at the snow-covered territory, it was midday.
“Wow.”

What unfolded before Lowell’s eyes was a scene completely opposite of the capital, Phoebos. The wind scattered flurries of snow, and all around them stretched endless snowy mountains.
So this is a place where it’s winter all 365 days.
Even Felix’s castle, rising tall among the peaks, looked nothing like what Lowell had seen in the capital. The high walls were topped with slitted windows, and the entire structure radiated a dark hue. It looked more like a fortress—or a prison—than a castle.

Of course. It’s right near the border, so the security has to be tight.
The guards standing near the castle stood at stiff, full attention. They bowed so low to the returning Felix that it made Lowell feel awkward just watching.
Are there more guards stationed because something might have happened while Felix was away?

Neighboring countries and nomadic groups were all well aware that Haloan nobles participated in the Blessing Month festivities. Because of that, border territories like this one often had to double or triple their security to prepare for potential invasions. Felix’s domain had long been a hot zone, with frequent wars breaking out along its borders. For the first few years, it had even been exempt from participating in Blessing Month altogether.
Whether that was an act of goodwill or not, who knows.
After Felix had proven once and for all the vast difference in power and ensured no one dared to violate the border again, the wars had nearly stopped. And recently, he’d even eliminated the battle-nomads—so things should be relatively safe now.

Since the peace is still fresh, it makes sense that the castle still looks like a fortress.
Lowell tried to talk himself into understanding the ominous exterior. But that was where his tolerance ended.
“Let’s go in.”

After accepting the knights’ greetings, they entered the castle—and Lowell was stunned.
“What… What is this…?”
Lowell's jaw dropped the moment he stepped inside. Not because it was beautiful. On the contrary, only a handful of attendants had come out to greet Felix. That wasn’t something that bothered Lowell personally. The interior design was rather sparse, but it wasn’t bad. Magical tools emitting fire-element magic kept the place warm enough to forget it was winter.

The problem was…
“Why are all the curtains drawn? It’s the middle of the day, but it’s pitch dark in here. Is it because of the cold?”
The entire castle felt less like a dim room and more like a sealed chamber. The curtains weren’t ordinary—they were blackout-level, plunging the interior into near-total darkness. Only a few soft lights—candle flames and glow spells—illuminated the space. Most of the furniture was in muted tones, giving the impression the place had been cursed and robbed of color.

Felix didn’t pick up on Lowell’s shock and started explaining casually, even with a hint of pride in his tone.
“The windows are enchanted with fire magic, so the temperature isn’t an issue. I’m a rare mage who uses dark-element magic. Since I train and conduct my research in this castle, it’s better without sunlight. The dark is more compatible with my magic.”
Lowell’s stomach turned. That explanation didn’t sit well with him at all.
“What does that even mean? So do fire mages train by sitting inside a bonfire?”

“There was a grand mage who did that, actually.”
Lowell was momentarily at a loss for words. Honestly, he didn’t care if some other grand mage wanted to live inside a fire, underwater, or hugging trees for life—that had nothing to do with him. But Felix shutting himself up in the dark to train? That wasn’t something Lowell could let slide.
This whole environment is a disaster! And no one ever objected to this? Do they think they’re children of darkness or something?

First, he had to change this depressing atmosphere. Even a healthy person could develop depression here. Felix was already more than powerful enough—he didn’t need more training. What he needed was emotional peace.
And this is how he ends up turning into the Demon King! Leaving things as they are is basically preparing a ritual for his descent. It’d be better if he had less magic!
Lowell had no intention of just sitting by now that he was inside the castle. He was going to overhaul everything from top to bottom. Fired up in a way that wasn’t like him, he swept his eyes across the dreary hall.

I’m changing all of it.
For the first time in a while, determination burned in him. Meanwhile, Felix was starting to grow visibly anxious. He finally realized that Lowell didn’t like his castle.
“You don’t like the castle?”

Felix asked the question with extreme caution. The attendants nearby flinched hard, then quickly lowered their heads. Several had to bite back screams at the unfamiliar sight of Felix nervously gauging someone’s reaction.
Lowell considered offering his usual gentle reassurance—but changed his mind. Some situations called for shock therapy. And this was definitely one of them.
“Yes.”

Lowell replied flatly. Felix’s pupils dilated wide, then slowly narrowed again. His eyes darted back and forth as if he couldn’t focus.
“I designed it to be the most suitable environment for my research. It’s not the glamorous capital. If you don’t like it, you’re free to cancel the engagement and leave.”
But even as he said the words, Felix looked like the world would end if Lowell actually left. He already seemed to regret saying it.

“So… what exactly don’t you like about it?”
Judging by his timid voice, Felix seemed willing to change anything. The attendants buried their heads even deeper. Ignoring everyone else, Lowell delivered his verdict.
“It’s too dark. The most important thing for a home is sunlight. First, sunlight. Second, sunlight.”

Lowell had been about to say “depression patients,” but changed it to “home” instead. He wasn’t sure if the concept of depression even existed in this world—and even if it did, Felix wouldn’t understand.
“As I said, this isn’t Phoebos. Sunlight is rare here. You have to adapt to that to live here.”
“Exactly!”

Lowell became even more agitated. Felix raised a brow as if asking what Lowell was trying to say.
“Since sunlight is rare here, why block it out with blackout curtains?! You’re shutting out the precious little sun you do get! The mood is already heavy, and this is bad for your health.”
The moment Lowell mentioned health, Felix visibly faltered. He didn’t know much about the relationship between sunlight and well-being, but since the word “health” had ★ 𝐍𝐨𝐯𝐞𝐥𝐢𝐠𝐡𝐭 ★ come out of Lowell’s mouth, he couldn’t ignore it.

“Then… we can change the curtains. Would that fix it? Let the sunlight in?”
Hearing that, Lowell realized that asking Felix to change the atmosphere of the castle himself would be pointless.
He didn’t even realize this environment was strange. What good would that do?

Which meant it had to be him.
“No. Leave the interior to me.”
“You’re pregnant. You need to rest. Let someone else handle it.”

Lowell shook his head immediately, leaving no room for argument.
“It needs to be an environment where I can rest. As it is now, there’s no way to feel comfortable.”
Felix closed his mouth. Lowell was normally gentle and accommodating, so when he pushed back forcefully, Felix had no idea how to handle it. He could only be dragged along by the current.

“Alright. Fine.”
In the end, Felix had no choice but to agree.
“But first, let’s eat. You didn’t have lunch, did you?”

Felix led the way toward the dining room, pulling along a still-fuming Lowell who kept eyeing the castle like he was mentally redecorating it already. When Lowell refused to budge, Felix even threatened to revoke his earlier permission if he didn’t eat something. Though reluctant, Lowell could tell he wasn’t bluffing and quietly followed.
This could be a problem.
Only then did something start to bother Lowell. His morning sickness had worsened again. The mere sight of food now made him gag. He’d already vomited several times after forcing himself to eat just a bit.

“Ugh.”
This time was no different. Even the appetizer, which had almost no smell, made him clamp his hand over his mouth the moment it hit the table. Felix stared at him with dim, unreadable eyes.
“Didn’t you say you were getting better?”

Lowell had lied in his last letter before leaving for the territory, claiming his morning sickness had improved and that he was eating well. It had been a foolish impulse, triggered by guilt over how much Felix had been worrying.
Some naive part of him had even hoped his symptoms might magically disappear once they arrived in Nyx.
Of course, that had been a hopeless fantasy.

“Th-That was…”
Felix’s eyes, locked on Lowell now drenched in cold sweat, were cold.