The Reincarnate Became a Professor at the Academy

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The black flames were creeping out, expanding their territory.

Like black paint splashed on a canvas.

The place known as the boundary was changing.

Demon Realm.

Or so it could be thought.

A place that was hospitable to those wielding demonic power.

'A domain, is it.'

Releasing one's own Manifestation to make the surrounding space more friendly to oneself.

Domain.

The term meant exactly that.

It was about spreading a space around oneself that favored one's combat style.

Using it to strip away the opponent's advantages.

Such were the Domains of transcendents.

A power that could be used by those who stepped outside the laws of the stars.

However, if it was a Demon King, the story changed slightly.

-Kuhahahahaha!!

He laughed.

Everything around began to respond to the Black Flame Demon King.

The black flame took shape.

I had an instinctive feeling that those things possessed abilities.

'What could it be?'

It's not destructive power.

The black flame itself was a highly destructive magic.

Then.

'Something like unavoidable attacks or multiplication.'

In a Domain, every attack might hit its target, or attacks could multiply.

Even that would be quite bothersome.

'Above all, it used contagion.'

Contagion.

Everything that touched the black flame is infected by it.

It was not about being burned by fire.

As it was burned, its speed became absurdly fast.

It could flow through the air.

The ability could only be used for attacks, and its versatility was lacking, but…

It was strong in its own right.

No doubt, this creature was extremely dangerous.

"You're pulling some annoying tricks."

"How is it? Can you use it?"

"Manifestation of Thoughts is nothing special. However…"

The Duke of Extermination looked at me.

Her unfolding of the Manifestation of Thoughts.

It did not distinguish between friend and foe.

Her Domain, crafted solely to kill her enemies, granted her fearsome offensive power.

Was that the price?

If allies were within the range of her Manifestation of Thoughts, most would die.

"It's alright."

I said with a smile.

I could withstand at least one hit.

That transparent armor was more useful than I thought.

'But if I get hit once, can it be repaired?'

If it was in the place called the Boundary, there might be production transcendents.

I set aside that thought for now.

More than that, I needed to kill that pig.

I was considering my means.

'Divine Thunderbolt, Heaven-Surrendering Godly Technique.'

With the completion of three rings, the power of the Divine Thunderbolt became tremendous.

Along with it, the Heaven-Surrendering Godly Technique also grew stronger.

And the Limitless Soul.

He called it my Manifestation of Thoughts, but that's only half true.

'It's not completed yet.'

Using the kaleidoscope, the Limitless Soul became complete.

Are you afraid?

The Black Flame Demon King spoke suddenly.

It was a bit ridiculous to hear such words from someone who looked like Zhu Bajie.

I understand. Someone who just reached the boundary wouldn't know much about me.

The Black Flame Demon King smirked.

A smile that seemed steeped in a sense of superiority.

In truth, what he said was accurate.

The domain he created prevents us from doing anything amongst ourselves for now.

'The problem lies with us as a group.'

A hurried voice could be heard from outside.

Since the principal was here, reinforcements would come if we stayed like this.

What he aimed for was to finish us before that time.

That was why he unfolded his Domain.

But what to do?

I was quite experienced in playing hide and seek.

However.

'I don't like it.'

I didn't quite like the situation.

Black Flame Heaven.

Fwoosh.

The sky turned black.

I chuckled quietly.

'Selfish bastard.'

To use such a great technique so nonchalantly.

I charged forward swiftly with Wind God's Steps.

As I approached close to him, the Black Flame Demon King's eyes widened.

'As expected.'

When this guy got hit by the Duke of Extermination earlier, I felt it.

'He lacks combat experience.'

He wielded great power in battle.

He fought and won with such tactics.

It was blatantly obvious.

'An ignorant type.'

Then the strategy was simple.

"Hoo."

I took a deep breath.

At that, the Black Flame Demon King flinched.

-When did he?

The Wind God's Steps reached its peak.

It allowed me to move faster than the Duke of Extermination.

Behind me, the Limitless Soul formed seals.

Three rings spun fiercely.

An enormous amount of mana enveloped me.

Ultimate Art, Divine Thunderbolt.

Crackle.

A colorless lightning gathered in the hand of the Limitless Soul.

I wielded the Wind God's Spear.

Whoosh.

An ashen flame blossomed at the tip of the spear.

Heaven-Surrendering Godly Technique.

A power that could break anything.

Ssssst!

Lines appeared on the body of the Black Flame Demon King. And with a splat! blood burst out.

'Is it because he's using the black flame that burns his own body through contagion?'

It began to penetrate with the Heaven-Surrendering Godly Technique.

-Wh-why?

The creature known as the Black Flame Demon King started to panic.

This changed the story a bit.

'Should I kill him?'

The fewer Demon Kings, the better.

The more of them there were, the more harm they caused.

If they decreased, the entire demon race disappearing would be nothing but beneficial.

I moved while stepping on the Wind God's Steps.

Crackle!

A blue lightning struck the side of the Black Flame Demon King.

'The Duke of Extermination's attack isn't very effective.'

There was a significant difference in attack power between her and me.

The sky and the earth.

Though not to that extent, it was like the difference between the ground and a great mountain.

'Of course, the Duke of Extermination is stronger now.'

For some reason, his defense was pierced by me.

'Is it because of the flesh of the Demon God?'

It strangely seemed to invigorate me.

Well, it was the relic of the Demon God.

With a Demon King targeting it, it might be cooperating with me.

'I should look into this later.'

But more importantly.

'Should I try to kill him?'

I think I can do it.

Crash!

I aimed for the shoulder of the Black Flame Demon King.

The moment Han Seojin decided to capture the Demon King, the Demon King also moved.

He still considered Han Seojin and the Duke of Extermination as prey.

Birds trapped in a cage.

Yet with sharp beaks and claws.

Even so, he believed he could catch them.

And the piece of the Demon God that the man possessed.

He would consume it and become the strongest Demon King.

Just as he was thinking that.

The world began to be drawn in lines of gray.

And then.

Splat!

The lines split apart. The entire world was gray lines.

'Why?'

How could that bastard's attack be working on him?

He was using the Demon God's flesh. Because of that, his own immortality was not responding.

'How?'

How could he use the Demon God's power so freely?

He knew the man was no ordinary being.

Splat!

While he was momentarily pondering, blood gushed from his body.

It was sudden. It hurt.

The more absurd thing was that the healing wasn't going well.

With a grimace, the Black Flame Demon King gestured. The black flame moved.

But the guy approached him at an unknown speed.

Splat!

He was slashed again.

'I must catch him.'

The black flames, with their unavoidable precision…

They were failing to properly capture the enemy.

More precisely, the moment they tried to approach, the enemy moved and evaded.

Too fast.

In that case, the entire space must be crushed.

The Black Flame Demon King reached toward the sky.

Whoosh!

Black flames filled the sky.

They fell toward the ground.

A method of pressing down the entire ground.

Han Seojin extended his hand while looking at the sky.

The Limitless Soul moved accordingly.

A colorless lightning bolt.

Ultimate Art, Divine Thunderbolt.

Three rings rotated fiercely.

A power resembling a morning star began to imbue the colorless lightning.

'Tsk, it hasn't been long since it was created, so it can't be applied directly to the Divine Thunderbolt.'

Still, being able to use it is something.

The power of the morning star, made to capture the demon kings.

It inherently contained the power of purification.

Golden morning star power imbued the colorless lightning.

A sphere condensed into a single point.

Rumble!!

It gained explosive power and soared into the sky.

The sky filled with black flames cleared.

-What.

The Black Flame Demon King was bewildered.

The power of purification.

He felt it. It was not the power used by gods. It was a true counterbalance, different from that.

While the Black Flame Demon King was flustered, Han Seojin quickly stepped forward.

Grip.

And grabbed the Black Flame Demon King's face.

'Now.'

The power of the morning star was barely imbued.

A slight golden force within the ashen flame.

Boom!

He punched the Black Flame Demon King's face directly.

-Kraaaah!!

He screamed.

A scream that suggested he wasn't accustomed to pain.

Instead of retaliating, he clutched his face.

Then, he should be hit once more.

Han Seojin swung his fist again.

Boom!!

A tremendous sound as if iron were exploding reverberated.

The Black Flame Demon King thought.

It hurts.

This was the first battle of its kind.

For him, battle meant a one-sided massacre.

But that bastard crossed the line he thought was the death boundary.

Furthermore.

Every time that bastard swung his spear, a wound was engraved.

This wound did not heal.

And the power mixed with ash and golden light. It was incredibly painful.

In the meantime, Han Seojin struck his face once more.

-Kuhuk.

A fist directly to the face.

Pain that rattled his very mind.

The Black Flame Demon King unconsciously took a half step back.

His face hurt terribly.

In the moment of almost kneeling unknowingly.

Kwaaang!!

That damn bastard's knee struck his head.

'Just the head…'

The bastard had been relentlessly targeting his head from the start.

It was actually effective.

Though he thought it was cowardly, that attack was disorienting him.

The other attacks were bearable. Painful, but nothing like this.

But the attacks slamming into his head rattled his very senses.

An unknown gray power. And the piece possessed by the Demon God.

He didn't know how the bastard was using them, but it was working.

Even with his head spinning, he tried to attack.

Black flames formed the shape of Purgatory Hell.

They targeted them, imbued with the power of certainty.

Meanwhile, Han Seojin thought.

'So you call yourself a Demon King.'

I tried to resist.

The black flames took shape, aiming at me.

Rumble!!

With the Ultimate Art, Divine Thunderbolt, prepared in advance with the Limitless Soul.

He incinerated it with that power.

'Normally, it would just retreat.'

The Demon God's flesh.

It was infusing power into him.

At first, it seemed like a form of self-defense.

'Does it want to devour me?'

He first carved it with the soul of an evil spirit.

But did it develop a consciousness? Perhaps the evil spirit has taken control of it.

Though lacking in ability, it might have resonated well with the flesh of the Demon God.

'This might become a problem…'

For now, I set aside my worries.

What stood before me now was the Demon King.

The first step was to eliminate him.

Whoosh.

I used the Divine Thunderbolt to repel the black flame, but a little still clung on.

-Khaha! You finally got hit by the black flame.

"So what."

Han Seojin remained unfazed.

His body felt a bit hot. But it was more bearable than expected.

Brilliant Blazing Fire.

And the Unique Trait, Eternal Sun.

His body was burning, but it was endurable.

'This is manageable.'

He gritted his teeth and endured.

Flare.

With half of his body engulfed in black flames, Han Seojin clenched his fist.

-What…?

The Black Flame Demon King wore a bewildered expression.

Han Seojin swung his fist at the face of the Black Flame Demon King.

Thud!

-Kraaaaah!!

He broke his nose.

Having relentlessly targeted the head, it was finally starting to break down.

-Stop, stop it!

The domain was being retracted.

The demon king was preparing to flee.

'As expected of a Demon King…'

Incredibly tough.

Even after being beaten like this, his body was still functioning.

'If it were an ordinary transcendent, they would have perished long ago.'

Han Seojin contemplated.

Should he just unleash the Heaven-Surrendering Martial Emperor?

Crunch.

A chilling sound of something being smashed.

The Duke of Extermination, who had approached unnoticed, kicked the head of the Black Flame Demon King.

"While you were beating him, it seems his immortality disappeared. So I kicked him with all my strength… but it only made him faint."

She let out a dry laugh.

"Hehe."

The Duke of Extermination gave a meaningful smile as she looked at him.

'Ah, so this was here.'

I thought seriously.

Now that the Black Flame was engulfing my body.

The only chance to escape was now, under the guise of treatment.