Chapter 1: Return of the Demon Instructor
Under the banner of the Justice Alliance lies the once-prestigious Yongcheon Academy, a place dedicated to nurturing the next generation of martial artists and healers. Within its grounds, the infirmary known as Bujingak served as a sanctuary for the wounded and a training ground for medical students.
On one of its beds, a man named Sabi Kang lay as if dead, until suddenly, his eyes snapped open.
“Gah! Huff! Huff! Huff!”
His body convulsed violently, like a fish out of water, before finally calming down. Slowly, he sat up, sweat dripping from his chin.
“Pant, pant, pant.”
He took a moment to catch his breath, then gingerly touched his bruised torso. His hands clenched and unclenched as he surveyed his surroundings.
The room was both unfamiliar and strangely familiar. The wooden beams and paper windows were sights he hadn’t seen in the demon realm. It was a place he had left long ago, yet it felt oddly like home.
“I’m… alive. And…”
I’m back!
Though he couldn’t pinpoint the exact time, he knew he had returned to the central lands. His body trembled with an overwhelming sense of joy.
“I did it… I really did it! Ha ha ha ha!”
Sabi Kang threw his head back and laughed, a sound filled with years of pent-up anguish that now dissipated into the air.
How long did he laugh like a madman? Suddenly, he sensed a presence and turned to see an old man staring at him with wide eyes and a grave expression.
“Who… who are you?”
The old man, Jin Baek, the head of Bujingak, shook his head disapprovingly.
“They said you were beaten senseless by some hooligans, and I thought you’d lost your mind.”
It was understandable. To wake up thrashing like a fish and then burst into laughter—it was enough to make anyone suspect he’d gone mad.
Sabi Kang looked over his battered body again. The injuries weren’t from the demon realm.
“The demon king’s sword pierced my heart, so these wounds…”
Jin Baek clicked his tongue and asked, “Do you remember anything?”
Sabi Kang searched his memory. Beaten by hooligans? Yes, he remembered. He had rushed to save a student rumored to have been kidnapped, only to be ambushed and beaten unconscious by masked assailants. It was a cruel prank by students who despised him.
If this was that time…
“Ten years before they appear?”
Jin Baek sighed and stood up. “How long will you let those students torment you? You need to toughen up. These days, kids fear nothing, backed by their clans and families…”
He trailed off, noticing Sabi Kang’s unusual demeanor. The once timid and defeated expression was replaced by a sharp, determined gaze.
“Are you… alright?”
“Do you have a mirror?”
Sabi Kang’s response was unexpected. He had never dared to meet the eyes of his superiors before, let alone ask questions.
Jin Baek, taken aback, handed him a mirror. “Here. Are you sure you’re okay?”
Sabi Kang examined his reflection. He looked younger, his face gaunt and weak.
“Pathetic. Was this really me? I can’t stand it.”
He returned the mirror. “I’m fine. Thank you for your help.”
“Ah, well. I’ve informed the headmaster that you’ll need a couple of days to recover.”
“Thank you.”
With that, Sabi Kang walked away, his mind racing. “Two days. I need to gather my thoughts.”
Jin Baek watched him go, shaking his head. “He must be in shock.”
**
Back in his room, Sabi Kang surveyed the familiar space with a cold gaze. His expression was hard, but inside, he was deeply unsettled. This was where he had laughed, worried, and grieved.
“Pathetic. Foolish and useless.”
He shook his head. His past self was pitiful, always cowering and seeking approval. But he couldn’t dwell on the past forever. Now, he had to live in the present.
“Everything starts now.”
His eyes sharpened with resolve. He had ten years. Ten years to prepare for the demon king’s invasion. It was a tight deadline, but he was determined.
“I’ll kill him. I’ll build an invincible army. I always repay my debts!”
He touched his chest, where the demon king’s sword had pierced him before his return. The memory still ached.
Just then, a voice called from outside.
“Excuse me, Instructor, are you in?”
Sabi Kang looked at the door. “Who is it?”
“It’s Yeon Woo-gyeong from the first-year Mokhwa class.”
Yeon Woo-gyeong? Sabi Kang frowned, then nodded. This was the student he had tried to save.
“Come in.”
Yeon Woo-gyeong entered hesitantly, then froze at the sight of Sabi Kang, who sat with his feet on the table—a posture he had never shown before, not even to students.
As Yeon Woo-gyeong stood there, Sabi Kang’s brow furrowed. “What do you want?”
“I… I wanted to apologize.”
“For what?”
“I heard you got hurt because of me.”
“Who said that?”
“What?”
“Who said I got hurt because of you?”
“Other students…”
“That’s nonsense. It’s not your fault, so don’t worry.”
“But you got hurt trying to save me…”
“You weren’t even there. The ones who should apologize are the students who lied about you being kidnapped. Unless you have something else to apologize for?”
“No, I don’t…”
“Then are we done here?”
“What?”
“If you have nothing else, you can leave.”
“Oh… okay.”
Yeon Woo-gyeong bowed and turned to leave, but paused at the door.
“By the way, I heard there’s a meeting in the Dragon Hall about those students. They might be disciplined.”
“Disciplined? Ha, what a joke.”
Sabi Kang laughed coldly. He knew the state of this place all too well. Decades of peace had left it rotten to the core. Instructors couldn’t touch the students, who were protected by their powerful families and clans.
Yet his past self had clung to hope, wishing for justice and an end to his torment.
How naive he had been.
“Ha ha.”
“Instructor?”
Yeon Woo-gyeong was still there, watching him. Sabi Kang’s expression turned icy.
“Didn’t I tell you to leave? I’m tired from a long journey.”
“Journey?”
Yeon Woo-gyeong looked puzzled, but Sabi Kang’s expression made it clear he wanted to be left alone.
After Yeon Woo-gyeong left, Sabi Kang sat in silence, lost in thought. Then he extended his hand, focusing his energy until a blue orb formed in his palm.
The orb glowed with a jade-like brilliance, a sight that would have mesmerized anyone. But Sabi Kang merely dispelled it with a dissatisfied grunt.
“Only two circles? I need more.”
The fact that he could do this much was thanks to the demonic power he absorbed when the demon king’s sword struck him, just before his return.
Sabi Kang leaned back, interlocking his fingers behind his head, and drifted into thought once more.
After being abducted to the demon realm, he had survived countless trials and tribulations through sheer determination.
In a world swirling with conspiracies and betrayals, he had clawed his way up to the position of Grand Duke of the demon realm.
He was well aware that the Demon King had begun to see him as a threat.
But he had grown complacent.
He hadn’t prepared enough.
His loyal followers, who were like extensions of himself, had been slaughtered by the Demon King while trying to protect him.
If he hadn’t prepared the ultimate fallback—‘regression’—he wouldn’t have been granted this second chance at life.
“First, I need to strengthen myself for certain revenge and preparation. For that, I need to acquire those items. I’ll start by collecting the ones nearby.”
Finally, he closed his eyes slowly.
It had been a truly long journey.
He wanted to rest, even if just for a little while.