The air in the lab was heavy and thick, reeking of chemicals and burnt metal.

It was strangely quiet now, except for the faint sound of machinery humming softly.

Aestrea stood amidst the chaos, his frame tense and alert as he looked at the old man standing across from him.

The man grinned, his crooked teeth yellowed with age. His wild gray hair framed a face that was half-mad with excitement.

And in his hand was clasped around a staff, its head aglow with pulsating dark energy.

“So,” the old man said in a voice that was raspy yet steady, “a rat sneaks into my lab and thinks he can stop me?”

Aestrea didn’t reply.

His expression was calm, blank even, but his sword was already raised, glowing faintly as a silver mana pulsed through it.

The old man tilted his head as his grin widened.

“No words? Fine, let’s see how long you can stay silent.”

With a wave of his staff, a bolt of dark energy shot toward Aestrea.

BOOM!

The explosion rocked the lab, scattering debris across the floor as Aestrea dodged to the side, his movements fluid and precise.

He didn’t waste a second, charging forward with mana-enhanced speed.

SWISH!

His blade sliced through the air, aiming straight for the old man’s chest.

CLANG!

The man blocked the strike with his staff, and the clash sent sparks flying.

“You’re quite fast…”

The man said with a small smile as he parried Aestrea’s sword back.

“But, it still isn’t enough!” he grinned.

Aestrea ignored his words, and instead, he pulled back his sword and swung again, this time aiming for the man’s legs.

The old man jumped, avoiding his sword and retaliating with a downward strike of his staff.

BANG!

Aestrea ducked, narrowly avoiding the blow as the staff hit the floor, cracking the reinforced metal beneath it.

『 First Move! (✦ Ice Lotus Bloom ✦)』

Aestrea’s sword glowed brighter as a faint silver aura enveloped it, and in a flash, he cut upwards.

An ice lotus formed mid-air; its petals spun rapidly before shooting toward the old man.

CRACK!

The ice crashed into the hastily erected barrier, freezing it upon contact. Shards of frost scattered across the room, and the man stumbled back, his grin faltering for a moment.

“Damn it… you fucking brat!”

He raised his staff again, calling upon a wave of black spikes to erupt from the floor and go towards Aestrea.

SHHHHKK!

The spikes tore through the air, but Aestrea was faster. He leaped into the air, flipping nimbly and landing behind the old man.

CLANG!

Their weapons clashed once more, their sparks flying as Aestrea pressed on.

The old man grunted, his movements were no longer fluid as struggled to keep up.

“Damn you!”

THUD!

Aestrea’s shoe connected with the man’s stomach, sending him flying backward. He coughed, clutching his side as he stared daggers at Aestrea.

“YOU FUCKING BRAT!”

He insanely slammed his staff into the ground, and the dark energy surrounding it pulsed outward in a massive shockwave.

‘Shit…!’

This time, even Aestrea couldn’t dodge.

BAM!

The force sent Aestrea flying, his back hitting the wall with a sickening breaking bones sound.

“A-agh… this… I broke a rib?”

Blood dripped from the corner of his mouth as he staggered to his feet, one hand clutching his side.

Pain radiated from his ribs, but he kept his calm.

The old man laughed loudly, the sound echoing across the lab.

“Hurts, doesn’t it? That is what happens when one goes up against a more powerful being!”

Aestrea wiped the blood off his mouth and looked at the man. He clenched his sword tightly and then took a step forward.

‘Alright, I got the hang of it now…’

‘He’s only an A+ ranker because his mana is desperately powerful. So, it should be even easier than dealing with a C+ rank demon beast.’

The old man’s laughter faltered.

“What’s with that fucking look, you brat?!”

Aestrea didn’t respond, instead, he lifted his sword once more, the blade shining brighter as his silver mana coursed through it.

『 First Move! (✦ Ice Lotus Bloom ✦)』

“That move again? Do you think it will work once again?”

The man scoffed as he quickly raised a dark barrier around himself.

However, something changed…

『 Reversal! (✦ Bloom of the Ice Lotus✦)』

The icy petals formed once again, spinning violently in mid-air.

However, they didn’t shoot directly toward the man’s barrier this time. Instead, they split apart, circling the room like a whirlwind of frost.

The old man’s confidence wavered.

“What the—?”

CRACK!

The frost began to creep up from beneath him, where his barrier didn’t cover. The swirling petals coalesced into sharp shards of ice, piercing through the weak spots in his defense.

“ARGH!” he screamed, the ice slicing into his legs and forcing him to his knees.

The attack didn’t stop.

The ice crawled over the barrier, creeping inward as the petals closed in.

Each shard shattered upon contact, releasing more frost and creating a web of cracks across the dark barrier.

CRACK!

The barrier broke, sending icy shards flying throughout the lab.

“NO!”

The old man roared angrily., his staff slamming into the ground once more to send another shockwave out.

BOOM!

The force sent the shards flying, but the strain was evident in the trembling of his hands. His breathing turned labored as he struggled to stand.

Aestrea didn’t give him a moment to recover.

His sword came down in an arc, aiming for the man’s exposed shoulder.

CLANG!

The staff met the sword, but the man’s grip faltered.

“You’re just a child! How are you—”

THUD!

Aestrea drove his knee to the man’s stomach, automatically cutting off his words and making him gasp in pain.

The man stumbled back, coughing violently as he tried to raise his staff again.

『 Judgement Eye (✦ S-Level Skill✦)』

A faint glow danced in Aestrea’s red eyes, analyzing the man’s weaknesses.

‘Left side exposed. Weak point at the ribs.’

He didn’t hesitate.

Swing!

The blade cut through the air, slicing deep into the man’s side. The blood spattered across the floor, and the man yelled in pain.

“AGGGHH! You… you little bastard!”

He screamed, desperation filtering in his voice.

A whirlwind of dark mana surrounded him, making Aestrea take a few steps back.

“I can’t lose to a brat like you,” he muttered.

His voice was trembling, his body was quivering.

“I’ve worked too hard for this… I won’t let it end here!”

He raised his staff one last time, the dark energy gathering into a massive orb at its tip. The air grew heavier, and the ground beneath them cracked under the pressure.

However…

Seeing this, Aestrea remaining calm expression, suddenly… smiled.

He reached out to his waist and pulled something out of it.

“T-this… I-I… n-no!”

The man immediately tried to revert his spell which had quite a long time to be launched.

But, Aestrea only smiled.

『 Ice Bullet (✦ Gunslinger Ice Magic✦)』

Tzing!

A bullet was shot towards the old man, making a hole in his chest before his body started turning into an ice statue at the speed of the naked eye.

The giant dark orb that he was about to launch disappeared into wisps, and those wisps quickly came back to him, unfreezing him.

“Too late.”

Aestrea, who was now in front of him, muttered to him in a cold tone.

“A-ah…”

The man fell to his knees, blood dripping from his mouth as he clutched at the shards of ice embedded in his body.

His staff clattered to the ground, the dark energy fading.

“You… you monster…!”

He muttered, trying to back away from Aestrea.

With each meter he crawled back, Aestrea also took a step forward, his blood-red eyes glowing ominously in the dim light.

The man’s breath hitched as he looked into those ominous eyes, his body trembling with nothing other than fear.

“Stay back!”

He cried, his voice breaking.

“You’re not human… You’re a demon!”

Aestrea raised his sword.

Sweep!

The blade came down in a quick, merciless arc, severing the man’s head from his body.

SPLURT!

THUD!

The headless corpse slumped to the floor, with blood pooling beneath it. The only sound in the room now was the soft hum of machinery somewhere in the distance.

Aestrea stood over the body, his chest rising and falling as he caught his breath.

His blood-red eyes clouded slightly as he cleaned his blade and turned toward the capsule containing the slime girl.

It still wasn’t over yet.

Source: Webnovel.com, updated by NovelKeep