The Yandere villainess loves the useless engineer

By the time Lillith and I returned to the manor that evening, she could barely hide how exhausted she was becoming.

Which was honestly terrifying.

Not because she looked tired.

Because this was the first time in a while I seen her tired.

The moment we entered my room, she immediately collapsed onto the bed before dragging me down with her. Both her arms wrapped tightly around my waist while she buried her face into my chest like she intended to fuse with me before falling asleep for the night.

Meanwhile my brain was still focused on the engine.

Pressure control.

Valve timing.

Boiler reinforcement.

The piston system still needed improvements before summer ended—

Summer.

My thoughts abruptly stopped.

Then slowly I looked down toward the black-haired menace currently attached to me.

"...Lillith."

"Mhm..."

Her voice came out muffled against my shirt.

"When are you supposed to go back to the academy?"

Lillith remained silent for several seconds.

Then casually—

"About two days ago."

I blinked.

"...What?"

"I was supposed to return two days ago."

I pushed myself upward slightly.

"You’re already late?!"

"Mhm."

"That’s bad!"

Lillith looked completely unconcerned.

"Not really."

"Yes really!"

I stared at her in disbelief.

"You’ll get into trouble!"

"I don’t care."

"What about graduation?"

Still completely calm, Lillith tightened her grip around me slightly before answering:

"I’m not going back."

The room became quiet.

"...What?"

"I decided after rescuing you."

Her voice remained soft and casual like she was discussing the weather.

"I’m staying with you forever instead."

I stared at her for several seconds trying to determine whether this was another joke.

It wasn’t.

She was completely serious.

"...Lillith."

"Mhm?"

"You can’t just abandon the academy."

"Why not?"

"Because you’re the heir to the Nightbane Duchy!"

"I’m still the heir if I leave."

"That is not how noble society works!"

Lillith sighed tiredly before looking up toward me.

"My father always keeps talking about how graduation is integral for incorporating yourself into high noble society."

"And he’s right!"

"I don’t care about high noble society."

Then quietly—

"I care about you."

That sentence alone probably would’ve sounded romantic under normal circumstances.

Unfortunately this was Lillith.

Which meant it sounded vaguely threatening instead.

I rubbed my forehead tiredly.

"...Your father is going to be furious."

"Probably."

"And what happens if he tries forcing you back?"

Lillith’s eyes narrowed faintly.

"Then we’ll fight."

The way she said it made my stomach drop immediately.

Not because she sounded emotional.

Because she sounded calm.

Completely calm.

I suddenly remembered the state of the capital after she found out about the war.

The destroyed buildings.

The shattered streets.

The fear.

Right.

A fight between these two was not a family argument. 𝚏𝕣𝐞𝗲𝐰𝕖𝐛𝐧𝕠𝕧𝚎𝚕.𝐜𝚘𝗺

It was a natural disaster.

That night I fell asleep deeply worried.

The next morning somehow started even worse.

Mostly because I woke up trapped beneath a sleeping Lillith.

Again.

One arm wrapped around my chest.

One leg across my waist.

Her face buried directly into my neck.

And despite supposedly being asleep—

The moment I tried moving, her grip immediately tightened.

"...Don’t leave."

"You’re unconscious."

"Mhm."

"Then stop reacting."

"No."

It took nearly twenty minutes of negotiation before she finally loosened her hold enough for me to escape the bed.

And once she fully woke up—

That was it.

Another entire six straight days of terrifying alertness had begun.

Unfortunately—

I barely even got through breakfast before disaster arrived.

The entire manor suddenly grew quiet.

Not naturally quiet.

The kind of quiet caused by fear.

Servants stopped moving.

Guards straightened instantly.

Then from outside the manor—

A pressure rolled across the estate.

Heavy.

Cold.

Overwhelming.

Even before stepping outside, I already knew who arrived.

Duke Rosthwall Nightbane stood at the front entrance of the manor with his usual composed posture, dark noble attire flowing lightly in the wind behind him.

Several Nightbane knights stood farther behind him, though none dared approach too closely.

Because standing directly in front of him—

Was Lillith.

The moment she saw her father, her expression immediately cooled.

"...Father."

"Lillith."

The duke’s voice remained calm.

Too calm.

His eyes slowly swept across her before stopping briefly on the way she was still standing close beside me.

Then finally—

"You’ve caused quite a lot of trouble."

Lillith looked completely unapologetic.

"Ok and?"

A faint twitch appeared near one of the duke’s eyes.

Small.

But noticeable.

"I’ve received reports that you destroyed military property inside another kingdom."

"They kidnapped Leo, and we are at war with them so I helped the kingdom."

"You also haven’t returned to the academy."

"I hated it there."

"And ignored direct summons from them."

Lillith shrugged lightly.

"They were boring."

The duke slowly exhaled.

Then finally his voice hardened slightly.

"You are returning to the academy."

"No."

The answer came instantly.

The air around the courtyard seemed to tighten slightly.

"I wasn’t asking."

"I wasn’t agreeing."

For several moments the two simply stared at one another.

Father and daughter.

Two monsters pretending to be civilized.

Then calmly Lillith spoke again.

"I’m staying with Leo until I die."

Every servant nearby visibly froze hearing that sentence.

The duke’s expression remained controlled.

Barely.

"Lillith."

His tone lowered slightly now.

"Your graduation is essential for inheriting the Nightbane Duchy one day."

"That useless place teaches me nothing."

"You know that isn’t true."

"All my teachers are weaker than me."

Her voice suddenly sharpened.

"They can’t teach me anything useful."

Then suddenly—

Pressure exploded outward from her body.

The temperature across the courtyard dropped instantly while purple mana spread around her like mist.

Servants collapsed to their knees immediately.

Several guards physically stumbled backward.

The sheer force pressing against the area made breathing difficult.

And through all of it—

The duke didn’t move an inch.

Not even slightly.

Instead he looked directly at her and calmly answered:

"The academy teaches far more beyond magic."

Then his own aura erupted outward.

The difference was immediate.

The pressure from Lillith already felt monstrous.

Her father’s felt absolute.

The entire courtyard shook violently beneath the force colliding between them.

I nearly collapsed instantly.

Every instinct in my body screamed danger.

This wasn’t an argument anymore.

It was becoming the same terrifying atmosphere from the capital incident all over again.

And if these two actually fought—

The Aldric manor would not survive it.

Lillith remained completely focused on her father.

The duke remained completely focused on Lillith.

Neither of them even noticed the damage already happening around them.

I desperately tried thinking.

How the hell was I supposed to stop this?

Nothing logical would work.

Nothing normal would work.

Then suddenly—

One idea appeared.

A horrible idea.

A terrible idea.

But...

It was the only one I had.

While enduring the crushing pressure around me, I forced myself forward slightly.

Then shouted.

"LILLITH!"

Her eyes immediately snapped toward me.

And before I could lose my nerve—

"If you graduate from the academy..."

I hesitated briefly.

Every survival instinct in my body screamed at me to shut up.

"...I’ll marry you."

Silence.

Instant silence.

The pressure vanished completely.

Lillith turned toward me so quickly it almost looked unnatural.

Her purple eyes widened slightly.

Behind her, even Duke Rosthwall looked caught off guard for the first time since arriving.

Now every single person in the courtyard stared directly at me.

I swallowed slowly.

Too late to back out now.

Lillith suddenly appeared directly in front of me before grabbing both my shoulders tightly.

"...Say that again."

Her voice sounded dangerously quiet.

I stared directly at her.

"If you graduate..."

My soul was actively trying to escape my body.

"...I’ll marry you."

Several seconds passed.

Lillith’s brain visibly stopped functioning.

Then suddenly—

She grabbed both sides of her head before dropping directly onto the courtyard floor.

"I DON’T KNOW WHETHER TO STAY OR GO—"

She rolled around onto her sides dramatically while clutching her hair in frustration.

"THIS IS SO UNFAIR—"

Every servant stared in complete disbelief.

Meanwhile I rubbed my forehead tiredly.

"...Lillith."

She immediately sat upright again before pointing at me accusingly.

"You can’t just suddenly propose to me!"

"You’ve been asking me for years!"

"That was different!"

"How?!"

"BECAUSE I DIDN’T EXPECT YOU TO ACTUALLY DO IT!"

I sighed heavily before stepping slightly closer.

"It’s less than three years until graduation."

Lillith visibly twitched.

Then I added carefully:

"And after asking me to marry you all these years..."

I paused briefly.

"...You’re really going to reject my one and only proposal?"

I deliberately emphasized only.

Lillith froze instantly.

Critical hit.

For several moments she simply stared at me with pure emotional agony written across her face.

Then finally she stood again before pointing directly at me.

"...Fine."

The word came out full of frustration.

"But if anything goes wrong—"

She stepped closer aggressively.

"Anything at all—"

Purple mana flickered faintly around her eyes.

"Then I’m dragging you back with me permanently."

"...Reasonable."

"It’s not a joke."

"I know."

Lillith narrowed her eyes at me for several more seconds.

Then suddenly—

She grabbed the front of my shirt and kissed me directly on the lips.

Hard enough that my brain completely shut down again.

Several servants immediately looked away.

Then finally Lillith pulled back before looking deeply into my eyes.

"...You better not die before then."

"...That is a very concerning response to a marriage proposal."

She ignored me completely before turning toward her father.

The duke still looked mildly stunned beneath his composed noble expression.

Then casually Lillith spoke:

"Let’s go."

And just like that—

The crisis somehow ended.

A while later the Nightbane carriage finally began departing from the manor.

Lillith leaned out the carriage window the entire time staring directly at me without blinking once.

The horses had already started moving before she suddenly shouted:

"DON’T DO ANYTHING DANGEROUS!"

"I LITERALLY ALWAYS DO DANGEROUS THINGS!"

"I’LL KNOW IF YOU DO!"

"That DOESN’T HELP!"

Then quieter—

And somehow more serious—

"I’m counting the days."

The carriage slowly disappeared afterward down the road.

And for the first time in weeks—

I realized Lillith was actually gone.

The silence afterward felt strangely unnatural.