The Daily Life of the Inventor in Another World

"We will see… I will be there as well."

"Hmm? Don't you have work?" Sona asked, her tone tinged with disbelief.

Snort

"One of his inventions reduced my working time by 80%. I finish most of my tasks before midday," Serafall responded smugly.

"Oh, now I remember! Brother was bragging about something similar. But he's quite tight-lipped about it too!" Rias recalled her older brother spending more time at home than ever, and acting smug about it as well.

"Yes, client confidentiality. Which you two will be signing," Serafall explained. With a snap of her fingers, two documents materialized.

"These will remain confidential until he's ready to reveal himself. You'll only need to keep quiet for a few years. After that, you can share this with anyone you like." She handed the documents to Rias and Sona, who quickly began reading them. The forms were basic and familiar, the kind they'd seen in devil school, and they understood what was required.

Without wasting any time, both signed the papers, and the documents vanished.

"You may reveal the information to your peerage, but under the condition that they cannot discuss it with anyone else," Serafall explained in a serious tone.

"I understand. Thank you," Rias and Sona both replied, acknowledging the gravity of the situation.

"Good. Then it's settled," Serafall said with a satisfied nod, though her watchful eyes remained on them. "For now."

"Umm... Sister… is he… well… you know..." Sona began, fiddling nervously with her dress.

She was still adjusting to the more serious, almost Satan-like version of Serafall.

"Know what?" The older Sitri glanced at her, clearly curious about her younger sister's line of questioning.

"You like... him?" Sona asked, her cheeks flushing slightly.

Serafall let out a small, amused giggle.

"You didn't hear this from me, but... yes, it would appear that I have a thing for men who can build wonders from scraps they find in a garage." She began to speak animatedly before sobering once more. "That's why you two will be on your best behavior. I've spent years building trust with him, and I'm not willing to lose it now."

"Sister... wouldn't it be easier for you to just say... that you like him?" Sona ventured, trying to make sense of her sister's rather complicated stance.

Snort

"I was summoned by him because I am Satan Leviathan. He summoned me to help set up pipes for his workshop—because of my expertise in water manipulation," Serafall explained with a roll of her eyes.

"I told you, didn't I? He's installed a pantheon-worthy security system in his hometown at the same age as you two."

"WHAT?!" Both girls exclaimed in unison, shocked by the revelation.

"He's the same age as us? And he summoned you for that?" Sona and Rias were both stunned.

"Which means I was qualified enough to be summoned," Serafall replied, not fazed.

"But... you're a Satan!" Sona pointed out, her voice thick with disbelief.

"And he single-handedly built a surveillance system out of nothing but a blob of clay. It'll last as long as the Earth rotates around the sun. What's your point?" Serafall replied with an eye roll, silencing both younger girls before they could voice any further objections.

"Creating things is much harder than destroying them. While my power is impressive, he's already found ways to outpace me."

"...He did?" Sona squeaked, astonished.

Sigh

"I already told you, he's a once-in-a-millennium genius. Do you really think I'd fall in love with someone average?" Serafall's frustration was evident. She had been growing tired of everyone looking down on Marcus. Sirzechs had learned better after seeing Signer's work; he was a fan now. And yet her sister still didn't fully understand the magnitude of Marcus's abilities. When she said "Pantheon-level security," she meant it.

"No... I mean... he's human..." Rias muttered, clearly trying to reconcile the idea of Marcus's genius with his status as a human.

"And what does that have to do with anything?" Serafall countered, raising an eyebrow. "Does being human mean he can't be smart?"

"How... does intelligence have anything to do with strength?" Rias asked, unable to help herself. This question drew several incredulous stares from the Sitri sisters.

Sona groaned. It seemed she had been too short-sighted.

"Simple enough," Serafall said with a smirk. "For example, he could build a weapon capable of killing an Ultimate-Class Devil."

"That's simply impossible," Rias said, shaking her head in disbelief.

"You want to bet on that?" Serafall challenged, her smirk widening.

Rias quickly shook her head. No, she wasn't about to bet on something like that, especially not with how serious Serafall sounded. Meanwhile, Sona was beginning to grasp the scale of the situation.

If her sister was willing to bet on it, then this human was indeed capable of extraordinary feats. This was very big. It meant Marcus was absurdly smart. Sona now found herself wanting to meet him.

"Wise choice," Serafall said with approval. "And since we're discussing him, I expect both of you to keep this information within your peerage. They're not to talk about it to anyone else."

"I understand, Sister. There's no need to threaten me so many times," Sona sighed, though she now knew her sister was only making sure she understood the gravity of the situation.

"I'm just making sure you two understand," Serafall replied with a knowing look.

""We do…"" Rias and Sona echoed in unison, both of them now fully grasping the magnitude of what they had just been told.

———

𝙅𝙤𝙞𝙣 𝙢𝙮 𝙥𝙖𝙩𝙧𝙚𝙤𝙣 𝙩𝙤 𝙧𝙚𝙖𝙙 𝘼𝙙𝙫𝙖𝙣𝙘𝙚𝙙 𝘾𝙝𝙖𝙥𝙩𝙚𝙧𝙨

-10 𝘼𝙙𝙫𝙖𝙣𝙘𝙚 𝘾𝙝𝙖𝙥𝙩𝙚𝙧

𝙋𝙖𝙩𝙧𝙚𝙤𝙣.(𝙘𝙤𝙢)/𝘽𝙡𝙖𝙢𝙚1

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