The Yandere villainess loves the useless engineer

She stood in front of me, only half a meter away, staring directly into my eyes.

Those eyes did not feel like they belonged to a child.

It felt as though an endless void existed beneath those crimson irises.

Duke Rosthwall stood opposite my father, silently observing our interaction before briefly coughing to break the cold awkwardness filling the air.

"I didn’t know you had a child around the same age as my Lilith," the duke said calmly.

"Perhaps the two of them could entertain each other while we conduct our meeting."

My mother instinctively stepped forward as if about to object, but my father gently placed a hand on her shoulder and whispered something into her ear.

Although I could not hear their conversation, I could clearly see the worried look on her face.

"I’m sure that would be an excellent idea, Sir Rosthwall," my father replied respectfully.

A servant was then called over and instructed to lead the two of us inside.

With every step I took, the nervousness inside me only grew stronger.

————

I stood alone inside one of the manor’s guest rooms.

In front of me was a child who, in the future, would bring unimaginable destruction and terror to the continent.

Yet all I saw now was a quiet little girl standing awkwardly while twirling her fingers together and occasionally glancing up at me.

To break the suffocating silence, I walked toward the corner of the room and rummaged through my toys before pulling out a small ball.

Holding it above my head, I asked, "Do you want to play catch?"

Lilith lowered her gaze toward the floor and quietly shook her head.

I tossed the ball aside with a sigh as realization slowly dawned on me.

What stood before me was not the terrifying Void Witch.

It was simply a lonely little girl.

Maybe the best way to stop her future destruction was not to avoid her...

But to help her.

For the next ten minutes, I tried introducing different games and toys, yet every attempt ended the same way.

A quiet shake of the head.

Until suddenly—

An idea struck me.

"Wait here," I told her.

I hurried toward the door and forced it open with all the strength my small body could muster. As I slipped outside, I glanced back through the slowly closing doorway.

Lilith stood exactly where she had been before, staring down at the floor.

But this time, I noticed something different.

Her face looked empty...

Yet strangely sad.

I ran through the manor’s halls toward my mother’s greenhouse garden. Outside, snow continued to fall gently from the sky as cold winds swept across the estate grounds.

I rushed through the rows of plants before arriving at a small storage shack near the edge of the garden.

Inside, I found exactly what I was looking for.

Fertilizers.

Well—not the fertilizers themselves, but the materials inside them.

I grabbed three different jars before hurrying back toward Lilith.

As I ran, memories from my old high school chemistry classes surfaced in my mind.

Sure, it was nowhere near as impressive as introducing advanced technology to a fantasy world...

But it should be more than enough to entertain a child.

————

Lilith stood alone in the room, silently staring at the floor just as she had after Leon left.

’Why is everyone afraid of me?’

’I didn’t mean to do it...’

’The maids avoid me. The servants refuse to speak to me. Even when Papa tries to introduce me to other children, they always find excuses to leave.’

The memory of the incident that isolated her from everyone else still lingered vividly in her mind.

But before she could sink deeper into her thoughts, the door slowly creaked open.

Leon peeked inside while carrying three jars.

"Psst. Follow me."

Lilith blinked in confusion.

’Why is he still talking to me?’

Before she could say anything, Leon suddenly grabbed her hand.

"You’ll like this," he said confidently.

————

I ran toward one of the manor’s unused fireplaces while holding Lilith’s hand with one arm and carrying the jars with the other. Slung over my shoulder was a small sack of copper dust I had "borrowed" from one of the weapon repair workshops.

We stopped in front of the fireplace.

Lilith looked around curiously before focusing her attention entirely on me.

Perfect.

I placed the jars down dramatically before turning toward her.

"Lilith, want to see a magic trick?"

She stared at me with visible confusion.

"Magic rainbow!" I shouted proudly.

I grabbed a small pinch of fertilizer from the first jar and tossed it into the flames.

The fire immediately shifted into a bright yellow color.

Lilith’s eyes widened slightly.

Then I threw in another powder from the second jar, causing the flames to turn orange-red.

Finally, I grabbed some copper dust from the sack and scattered it into the fire.

The flames instantly transformed into a glowing emerald green.

And for the finale—

I tossed in the final powder.

The fire burst into a deep lilac-purple color that illuminated the entire room.

Honestly...

Who would have guessed a dumb little chemistry experiment from high school would actually become useful in another world?

Most of the necessary materials had been hidden inside the fertilizers from my mother’s greenhouse. Sodium, potassium, calcium—

The copper had been easy enough to find as well.

Feeling rather proud of myself, I turned toward Lilith, expecting a shocked reaction.

Instead, I saw something far different.

Awe.

Pure awe.

Her deep purple reflected the shifting colors of the flames as she stared at them in complete fascination.

After several long seconds, however, her expression slowly became nervous.

Then, in a quiet voice, she asked,

"Why are you not scared of me?"

I stared at her blankly.

Confused.

Sure, she could look a little intimidating sometimes...

But nothing about her was actually frightening.

"Why would I be?" I asked honestly.

Lilith opened her mouth slightly as if trying to answer—

But before she could speak, the sound of approaching footsteps echoed through the hallway.

Crap.

I immediately grabbed the jars and shoved them behind a nearby curtain before rushing back to Lilith’s side just as the doors swung open.

"So this is where you two have been?"

Duke Rosthwall stepped inside alongside my parents.

My mother visibly relaxed the moment she saw me unharmed.

"It seems the two of you have gotten along surprisingly well," the duke said.

"However, Lilith, it is time for us to return to our territory."

Lilith slowly looked back toward me.

For a brief moment, the usual emptiness in her crimson eyes seemed weaker.

"...Can I come back someday?" she asked quietly.

The entire room went silent.

Even Duke Rosthwall looked mildly surprised.

I, meanwhile, felt my soul nearly leave my body.

My father awkwardly cleared his throat while my mother stared at me in disbelief.

The duke’s gaze shifted toward me before a faint smile appeared on his face.

"That," he said calmly, "will depend on Baron Aldric and his family."

Every instinct in my body screamed danger.

But as I looked at Lilith standing there nervously clutching the edge of her sleeve...

I couldn’t bring myself to reject her.

"...Sure," I answered carefully.

Lilith blinked.

Then, for the first time since arriving at the manor—

She smiled.

It was small.

Almost unnoticeable.

But the moment it appeared, the cold atmosphere surrounding her seemed to disappear entirely.

And somehow...

That terrified me even more.

————

Not long afterward, the Nightbane carriage departed from the Aldric Territory beneath the falling snow.

The black-armored knights rode ahead while Duke Rosthwall sat inside the carriage across from Lilith.

For most of the journey, silence filled the interior.

Then suddenly—

"Papa."

The duke glanced down at his daughter.

"Yes?"

Lilith hesitated for a moment before quietly asking,

"When can we visit Leon again?"

Rosthwall’s eyes widened slightly.

Because for the first time in years—

His daughter actually sounded happy.