Chapter 1

In the deepest part of the underground cavern, a giant humanoid figure over ten meters tall — the Demon King — had a shining holy sword piercing his chest.

"Impossible... I, who was to rule the world as the Demon King, to be defeated by such a puny human..."

"Hey, you're getting ahead of yourself, calling yourself the ruler of the world before you've even conquered it."

The man with golden hair and blue eyes, who was gripping the holy sword with both hands, tried to push it in further.

"I don't remember your name, but the name of the one who defeated you will be a fine souvenir for the underworld. I am Sieg Andreas. And—"

Sieg infused the holy sword with magic.

"My dear friend Mathis Lutius is the 'Supreme Sage' who brought you 'death'!"

The holy sword glowed.

A surge of holy power, transformed into a massive blade, pierced the Demon King's "core."

"Y-You... You dare to destroy even the 'Magic Furnace of the Underworld'..."

"It's too much for humans. Naturally, it's too much for demons as well. Erasing you completely is for the good of the world."

Sieg smiled and a shout came from behind him.

"Get back! You'll be caught in the explosion!"

"Whoa. We just defeated the Demon King; it would be a waste to die here."

Sieg kicked the embedded holy sword and leaped backward.

When he landed, a young man was crouching, protected by a magical barrier.

He had black hair and black eyes, and was a tall, slender, and handsome youth, though shorter than Sieg.

"I'm drawing the magic circle. All you need to do is infuse it with magic. Can you still do it?"

"Piece of cake. But you, really, to have everything go so smoothly..."

"We can talk later. I have a lot to say to you, but right now we need to get out of here quickly."

"Sure, sure. I'll listen to your lecture later—!"

He poured all his magic into the magic circle on the ground.

The two were enveloped in light and disappeared from the spot—.

In a forest that seemed to absorb the sunset, Sieg and Mathis reappeared.

They had used the lost ancient secret technique—'Teleportation Magic'—to transfer.

The ground rumbled. A massive explosion sound shook the air from a distance.

"Look, Mathis, the mountain is blowing up."

Through the gaps in the branches, they could see the mountain in the distance, its top blown off and smoke rising.

"It's the result of the magic furnace's malfunction. The power is just as the legends described."

"Did the holy sword get blown away too?"

"Maybe. Even if it wasn't destroyed, it would be hard to find. But Sieg—"

Mathis looked at his friend.

"I appreciate you protecting me with a magic barrier right from the start. But using a 'Divine Barrier' was excessive. It made you consume extra magic, and you might not have been able to destroy the magic furnace fused with the Demon King's core."

"Do you think I'd make such a mistake?"

"…No. But! If you, the strongest hero, were to be lost—ouch!"

In the middle of his speech, Sieg snapped his finger and flicked Mathis's forehead.

"Listen, Mathis. Heroes are disposable pawns. If one becomes useless, you can always get another. The one who should be prioritized is someone like you, who can create heroes."

In the worst case, he intended to activate the teleportation spell remotely to save Mathis alone.

"As long as you're alive, we can rebuild. You can train many heroes better than me, right?"

"Don't be ridiculous. I have no talent for swords or magic. I'm just a bit cunning and insignificant. Without your 'luck,' I would have been buried and never achieved a noble rank."

"I like your modesty, too."

"…Don't mock me."

In truth, Sieg recognized Mathis as a superior talent.

He was terrible with swords and could only use basic magic, but his intellect had revived several lost ancient secret techniques, led the army to victory after victory, and accurately identified the talents of others, discovering many talents at the young age of nineteen.

The best example was 'the Strongest Hero' Sieg Andreas.

Sieg, who had excessive power and handled magic carelessly, was known as a 'Rampant Dragon' and would have been condemned long ago if not for his noble birth. He firmly believed that he became a hero thanks to his friend Mathis's guidance.

"What needs to be protected is not a pawn but a sage with the power to rule the world."

He believed that once he defeated the Demon King, his purpose would be fulfilled. However, the world at peace would need the intellect of the 'Supreme Sage.'

Just as Mathis was about to argue, a calm voice interrupted.

"Are you both safe?"

A beautiful woman with long, wavy golden hair, her large chest visible even in her loose white cleric's robe, smiled at them with kindness.

"Teacher!"

"..."

She was their mentor, Isabella Sharier, who served as the strategist of the Demon King extermination force at the young age of twenty-four.

"Still, it's impressive that you managed to escape from the depths of the cavern to here. Did you use some special magic—"

Isabella's words were cut off by Mathis.

"Thanks to Sieg. More importantly, how did the diversionary force fare?"

"Thanks to you, they were able to retreat before the explosion. The communication magic you developed is amazing."

"It can only send signals for now. It will take a long time to enable two-way communication."

"Still, it's something to be proud of. I have been blessed with wonderful students."

"Well," Isabella said with a smile.

"The troops are still in chaos. I need to organize them. General Gadif's and Viscount Gustav's forces are waiting ahead. Please rest there first."

After saying that, she left the scene.

"Then, let's go."

"Sure—ouch!"

Sieg picked up Mathis and carried him in a princess carry.

"Hey, Sieg! You're the one who's tired—"

"I still have magic and strength left."

Ignoring his friend's words, the strongest hero dashed forward.

They successfully joined their allies, but—

The news of the Demon King's defeat brought joy to the Holy Capital, only to be followed by a shocking report.

The hero Sieg Andreas had been killed in an attack by the demons.

A few days later, a young man was accused of leading the remaining demons.

With black hair and black eyes, the Supreme Sage Mathis Lutius stood in the defendant's seat of the Holy Capital's Grand Court—.