Seven Sins System Chapter 857. Successful Experiment

Seven Sins System Chapter 857. Successful Experiment

My jaw tightened. “This place…”

I looked around again, memory flashing.

The necromancer’s mind.

Broken images.

Old room.

Crystals.

A seller in gloves.

“It’s the same.”

Mamon stopped. “What?”

“The place I saw in the necromancer’s mind.” I slowly turned. “A bit different. But it’s here.”

Luci’s bird eyes narrowed. “So the seller used this place?”

“Or met here.”

Mamon walked toward the center. “The school above may have been built later to conceal it.”

“Or they chose the school because it gave them access to children,” I said.

That possibility landed hard.

Luci’s voice sharpened from my shoulder. “Just work.”

I slowly turned my head toward him. “You better help us.”

He ruffled his feathers. “I don’t do peasant work.”

I stared. Then one tentacle lifted behind me, curling close to his tiny bird neck. “Work or I will choke you with my tentacles.”

Luci tched. “Bad temper. No patience.”

“You just described my personality as Wrath. Thank you very much.”

“You’re welcome.”

He jumped from my shoulder.

Midair, violet light wrapped around him. The bird shape stretched, unfolded, turned back into Luci’s human form. He landed gracefully on the stone floor, mask still on, coat untouched, expression deeply offended by physical labor.

He dusted his sleeve. “If this place ruins my clothes, I will destroy it.”

“We’re probably destroying it anyway.”

We searched.

Mamon handled the residue lines and transaction traces. Luci inspected walls, symbols, crystal alignments, and hidden pride signatures because apparently pride residue had a specific arrogance pattern. I checked the floor, machines, soul stains, and anything that smelled like Wrath or Envy contamination.

Nothing obvious.

No hidden doors.

No cage.

No creature.

The large aura we felt above was gone.

Or worse… Distributed.

That thought crawled under my skin.

We searched longer.

Five minutes.

Ten.

Mamon was now visibly pissed.

A quiet Greed anger where numbers failed to balance and someone somewhere was about to lose everything.

Then he stopped near an overturned cabinet.

His fingers brushed against a loose panel.

-Click!

A drawer slid open from inside the stone wall.

Mamon reached in and pulled out a book.

Old. Black cover. No title.

But the moment it touched his hand, the room’s temperature dropped.

“I found a book.”

“Read it.,” I said.

He opened it.

The pages flipped fast under his fingers, too fast for mortal eyes. Gold light reflected in his glasses as he scanned formulae, names, procedures, charts, diagrams.

One page.

Ten.

Fifty.

His face changed.

Not much.

But enough.

The color drained slightly from his expression.

Mamon did not go pale easily.

Luci noticed too. “What?”

Mamon kept reading. “This book contains what they did with the residues.” His voice was quieter now. “And the experiments.”

I walked closer.

“And?”

He didn’t answer right away.

That silence was bad.

I looked at the diagrams over his shoulder.

Artificial blessing.

Artificial sin tolerance.

My stomach twisted.

Mamon finally closed the book. “The experiment was successful.”

I stared at him. “Where is that creature then?”

Mamon looked at me.

Then at Luci.

His voice went flat. “Those children are the successful experiment.”

Silence.

Absolute silence.

Luci’s hands curled slowly into fists. His mask hid his face, but his aura said enough.

Mamon stared down at the book like it had personally robbed him. “They didn’t create one creature,” he said.

“They created a system.”

The words stayed in the air like poison.

For one second, none of us moved.

Three devils who had seen wars, betrayals, divine massacres, demon rebellions, soul pits, corrupted saints, fake gods, and Asmo’s stupid decision-making.

And we looked at each other.

Then, almost at the same time, said, “Oh no.”

The ceiling above us trembled. From resonance.

Like hundreds of small heartbeats suddenly syncing into one massive pulse.

My blood went cold. “Puriel.”

Luci’s face sharpened. “Lumira,” he said at the same time.

Mamon snapped the book shut so hard dust exploded from the cover. “We need to warn them.”

Luci’s jaw tightened. “I hope those kids still remain kids.”

Mamon muttered, “See? I hate kids.”

We teleported at the same time.

The underground chamber vanished.

The surface hit us like a punch of sunlight and schoolyard noise.

We appeared near the yard.

And everything was wrong.

The children had gathered around Puriel and Lumira.

Their little faces tilted upward toward the angels with innocent eyes and small smiles. Some clutched backpacks. Some held stuffed toys. One boy still had a juice box in his hand. A little girl with pigtails stood nearest to Puriel, arms lifted like she wanted to be carried.

And Puriel had picked her up.

The girl sat in her arms, cheek near Puriel’s shoulder, tiny hand gripping the cloth near her collar.

Puriel’s face showed softness.

A softness even I never got.

That gentle, protective warmth angels gave naturally to children, like every small life was something sacred.

Lumira stood nearby, surrounded by more kids, one hand lowered to calm them, golden light wrapping gently around their shoulders.

My stomach dropped.

The three of us rushed forward.

I yelled before I even realized I was moving. “Puriel! Get her off!”

Puriel looked at me. Shock flashed across her face. She didn’t understand yet.

The girl in her arms giggled. A sweet sound. Then her arm changed.

Bone, flesh, and shadow twisted together into a thin spear-like limb, dark and glossy, pulsing with residue.

It drove straight into Puriel’s chest.

Into her core.

Puriel’s eyes widened.

The world slowed.

Her wings flared violently behind her, silver-white light bursting outward in panic. The girl smiled up at her, face splitting into something that still looked like a child and somehow not a child at all.

“Angel…” the girl whispered.

Her voice was hoarse.

Layered.

Like something huge spoke through a tiny throat.

Behind them, Lumira cried out.

I turned just enough to see another child strike her too. A boy this time, arm warped into a jagged blade. Lumira twisted at the last second, golden wings snapping inward. The strike missed her core by a breath but tore across her abdomen.

Not deep enough to kill.

Deep enough to corrupt.

A black-gold hiss rose from the wound like acid touching sunlight.

Lumira gasped, one hand pressing to her side.

Then the children smiled.

All of them.

At once.

I teleported.