A cave into which no light entered.
Inside it, I shared a final conversation with an old friend.
"In the end, it's just you and me left."
My current age was 182.
The war had begun when I was twenty-five, meaning I had endured for a full 150 years.
"Isn't it amazing? I survived after participating in every battle that would go down in history. At first, I even thought I must be an incredibly lucky person."
Of course, all of that was due to my lack of skill.
I was always stationed in the rear, far from the front lines of battle.
Still, despite standing on countless battlefields, I had survived steadfastly and enjoyed a lifespan exceeding a hundred years—so in the end, couldn't it only be explained as luck?
When the human kingdoms destroyed themselves after killing each other endlessly.
When humanity's natural enemies massacred countless people.
I alone survived and managed to make it this far.
"Thanks to that, I learned a lot and consumed every elixir worth eating. When I discovered hidden treasures, I can't tell you how good it felt. I still remember it vividly. I've always had a really good memory."
There was no place I hadn't been, no enemy I hadn't fought, and I explored ancient knowledge.
I had no talent, but I was born with exceptional memory, so I never forgot anything I saw even once.
Because of that, after countless twists and turns, I survived longer than any other human and, through fortunate encounters, even reached the ranks of the greatest masters.
Wasn't it said that the one who lasts the longest is the strongest?
"But what's the point of that? There's no one left to share it with or boast to."
All the people dear to me died right before my eyes.
A life where, every time, I could do nothing but flee.
I could never shake off the self-loathing that everything was my own weakness.
With even the slightest negative thought, my mind would inevitably crumble.
Truly, I was a pitiful being, with both miserable talent and a fragile mind.
And yet, I could never let go of my attachment to life.
That was probably why.
To endure somehow, I lived with a positivity bordering on mania.
Because I clung on so desperately, I was able to reach this moment.
It was while thinking that—
"Did you choose this place as your grave? How pathetic."
A man entered the cave.
His appearance was almost identical to that of a human, but he was unmistakably a different species.
Blue eyes, silver hair, and distinctive small horns.
A race that had once been driven to the fringes by humans and lived as if dead, only to trample over humans and emerge as the final victors.
Rakshasa.
They had appeared before me once again.
To take my life.
"This cave stinks."
"Well, what do you expect? How many times do you think I took a shit in here over two years? Get used to it."
The man frowned and pinched his nose.
Even so, his eyes never left me for a single moment.
This time, his gaze was determined to kill me for good.
So what?
I had no intention of running away anymore either.
"Wait a bit. Let me have a final heart-to-heart with my friend."
"Friend?"
The man sneered, then laughed incredulously before continuing.
"That lump of rock is your friend?"
"Hey! Watch your mouth. What if my friend hears you?"
I said that, but it really was a lump of rock.
"Say hello. This is my friend, Jonsun. Jon from existence (存), and Sun from a jade name (珣). Jonsun."
An imaginary friend I created after losing all my comrades.
After my last companion died, I went a long time without speaking.
No—more accurately, I couldn't speak, because there was no one to speak to.
As a result, my tongue stiffened, and even when I occasionally encountered surviving human slaves, words wouldn't come out.
My breath smelled awful too.
So I made Jonsun.
Only then could I forget, even a little, the loneliness that gnawed at my sanity.
Even talking to oneself requires someone to talk to.
"There's no need to rush, right? It's been a while—how about we start with a cup of tea?"
"If you hadn't run away like this, it would've ended long ago."
"Don't worry. I won't run anymore. This ends here."
I was sick of running away.
And this cave wasn't something I found to flee, but to win.
But maybe because I thought it was the end—
Facing his face filled me with a deep sense of regret.
"In the end, I never beat you even once."
"With your ability, it'd be impossible even if you had another hundred years."
"You don't have to say it. I know better than anyone. My masters said the same thing. That I had a cursed body."
The three masters I had formed master-disciple bonds with all said the same thing.
A cursed body without even a trace of talent.
Meanwhile, the one standing before me was a genius said to appear once every thousand years.
Between the two of us was a chasm so deep it could never be crossed.
No matter how high I climbed as a master, the wall of talent was insurmountable.
I couldn't overcome the limits of talent.
"Thinking about it again, it's absurd."
How did someone like me even survive?
There were countless masters in the kingdom, yet the one who survived the longest was someone with miserable talent.
It was a question I had always harbored, and one I still hadn't resolved.
That was why I came to this cave.
What if I hadn't been the last survivor?
Would the future have been different?
To find the answer to that question.
"By the way, aren't you curious? Why did I suddenly get caught like this? Even I think I was really good at running away."
"Not really. Your end is already decided."
"No, no. Think about it. Isn't it strange? Waiting calmly in a cave with only one entrance until you arrived. Just like I chose this place as my tomb. Doesn't that seem odd?"
"I said I'm not curious."
"Come on, it's free—just listen. Otherwise, you'll really regret it. Why didn't he run? Does he have some other scheme? You'll spend your whole life unable to sleep properly, stuck with questions that have no answers."
"Farewell. Old enemy."
A sword flew toward my neck.
As always, his attack was swift and clean, leaving no time to even feel pain.
And then my vision flipped over.
'You must be curious.'
Of course, I had no intention of reacting.
Everything was going according to plan.
'You fool. You should listen to people until the end.'
Even as I died, there was surely a smile on my lips.
'You'll regret it deeply.'
One day, while wandering aimlessly.
I discovered a single fact in an ancient manuscript.
The Stone of Regression.
For over a hundred years afterward, I searched for its traces, and finally found this cave.
Then I discovered another fact and was utterly shocked.
'The cave itself is the stone.'
It wasn't an object—the cave itself was the Stone of Regression.
So I waited for him in the cave, and finally met my death.
Now it was time to see whether the ancient manuscript was true.
If it was the truth, without a single lie—
'I return to the past.'
To the optimal point in time to take revenge on him.
'Let's start over from the beginning.'
To avoid repeating a history stained with blood.
The Stone of Regression was difficult to activate.
Because the cave itself was the stone, one had to die inside it, and not by suicide, but by being killed by the blade of someone harboring hostility.
That was why it was also called the Stone of Vengeance.
It granted a chance for revenge.
I fulfilled those conditions perfectly.
And fortunately, the contents of the ancient manuscript were true.
'I really came back....'
The me who should have died with my throat cut was now looking at the world with my own two eyes.
As I turned my gaze to look around, I was forced to stop.
A house bathed in bright sunlight.
Next to a shabby gate made of brown wood was the family crest, and beneath it was someone's name.
As I traced that nostalgic name with my hand and pushed the gate open—
A man standing in the not-so-large yard filled my vision.
In that instant, everything seemed to stop.
"Aren't you coming in? Aren't you going to eat?"
A voice so old I almost forgot it.
The young man in his mid-thirties wore a gentle smile.
"What's wrong? Is there something on my face?"
"...No. There isn't."
"What is it? Did you fall for me because I'm too handsome? Hahaha. You punk."
I finally remembered that foolish joke.
Though his words sounded light, they were filled with love.
My father, Lee Sangwon.
The father who had loomed like a great mountain in my memories now stood before me as a young man.
"...Yes."
Perhaps because he hadn't expected such a serious answer, my father looked momentarily flustered.
Seeing that, a laugh escaped me unconsciously.
"You look just like me. Of course you're handsome."
"Well now, you've learned how to talk back. Stop saying nonsense and get ready to eat."
As he turned away as if nothing was wrong, I was once again able to grasp reality.
"I'm back."
Back to the childhood home buried in my memories.
Only now did it truly sink in that I had regressed.
"Really...."
It was a regression I had longed for even in my dreams.
At the dining table, it was just my father and me.
My mother had passed away not long after I was born.
They said complications from childbirth had worsened her chronic illness.
It was somewhat regretful that I couldn't regress to a time when she was still alive, but it wasn't something I was dissatisfied with.
It was September of the year I was fourteen.
Not the best, but still a positive point in time.
'There's plenty of time before the military exam.'
The military examination (武科).
It was a national exam held to recruit military officers.
Excluding the lowest class, it was open to everyone, and one could take it starting at the age of eighteen.
'That's why it was also called a field of opportunity.'
Becoming an official warrior meant carrying out missions for the state, but it also came with various privileges, making it the starting point of my plans.
'Last time, I barely passed at twenty-five.'
But I was different now.
This time, no matter what, I planned to take the military exam as soon as I turned eighteen.
'It's fine. I can do this.'
After learning about the Stone of Regression, I memorized everything recorded about the future.
Because I had to create change to avoid repeating the same history.
The plan I formed over that long time was this:
Save masters who died meaningless deaths.
Help geniuses who met tragic ends because they couldn't grow, and seize secret manuals and treasures before they fell into enemy hands.
And before carrying out that plan, there was one prerequisite.
That I myself had to become strong.
'Let's start today.'
For someone as talentless as me to even follow in the footsteps of geniuses, I couldn't waste a single moment.
Maybe my expression darkened as I mulled over future plans.
My father looked at me with concern.
"You don't look well. Is it because the headmaster called you?"
"The headmaster?"
I was briefly confused, but soon remembered what happened around this time.
September, at fourteen, one month before the promotion exam.
The headmaster, Yang Geumho, had told me to bring my parents.
To recommend that I drop out.
That I had no talent for martial arts and should quit and find another path.
There was a reason the headmaster said that.
'I didn't meet his expectations.'
My background was the Cheongsin Lee clan, a powerful family.
Founded by my grandfather, it was one of the most influential families in the kingdom.
Then why were we living in this shabby house in the countryside?
Because my father had left home to become an apothecary.
Since the family recognized no profession other than warriors, my father was treated as half-abandoned, and all support was cut off.
But regardless of the circumstances, to others, only the name mattered.
To commoners, Cheongsin was an illustrious family far beyond reach, and for a rural academy headmaster, it was an opportunity he couldn't pass up.
That was why he even offered to cover all expenses to recruit me.
'Just having the signboard that someone from Cheongsin attended was enough profit.'
But despite the headmaster's great interest—
As I repeatedly received the worst scores and failed over and over, that interest withered and turned into disappointment.
It was only natural that his support stopped.
'That's why he recommended I drop out.'
If you bring in a young master from a renowned warrior family and fail to produce results, the academy's reputation wouldn't just stagnate—it would plummet.
He probably wanted to send me elsewhere to avoid taking the loss.
'And I stubbornly refused.'
In hindsight, quitting would have been the right choice.
But as a child, I refused to back down, insisting I would take the promotion exam no matter what.
That I simply hadn't shone yet.
That my talent would soon bloom—I turned away from reality.
All without knowing that I would humiliate myself in front of my father.
'Even now, it's embarrassing.'
There probably wasn't another day I cried as bitterly as that one.
But this time would be different.
For a fourteen-year-old, it might be the hardest test of their life.
And my life had been one of rolling through misery due to my pitiful talent.
But I was no longer a hot-blooded child.
Inside this youthful body resided the experience and knowledge accumulated over 180 years.
'I can't fail at even this.'
No matter how young my body was or how my stamina had vanished, if I couldn't pass this, I had no future.
That was when my father spoke.
"No matter what people say, it's fine. It's okay to be a little late. Even if you start late, the one who goes to the end is the one who wins. Understand?"
"Yes. You've said that often."
"Have I?"
"Of course."
I believed those words and went all the way.
No—I still hadn't reached the end.
I was still running toward it.
Dongsan Academy (東山學館).
My first academy, existing faintly in my memories.
But I felt not even a shred of fondness.
"Still unlucky, even now."
With every step past the academy gate, memories resurfaced as vividly as if they were from yesterday.
Those days when I was ostracized simply for lacking skill.
Days when I feared tomorrow so much that I wished the sun would never rise.
They filled my mind.
"I'd forgotten about it."
They were truly filthy memories.
Then, from behind, I heard a youthful voice.
"What? The young master came again today?"
Passing the military exam and reaching even upper ranks was already impressive, but Yang Geumho had one unfulfilled dream.
To become a Sage (仙人).
The true beginning of a warrior, attainable only by those with overwhelming skill and countless merits.
That was why Yang Geumho, after earning educator qualifications through various missions, opened an academy and devoted himself to producing a Sage.
And the boy openly mocking me right now was his only hope and sole son.
Yang Taesik.
"I thought you wouldn't come today since you went home crying yesterday. You've got more persistence than I expected?"
Yang Taesik struck the back of my head and grinned smugly.
Back then, he seemed huge, and I couldn't even talk back.
But now, he was just an immature fourteen-year-old kid.
"Did you just hit me?"
"What?"
Perhaps because he hadn't expected me to retort, he frowned.
"Was that to me? You want to die, huh?!"
Yang Taesik raised his hand threateningly, but there was no need to even pretend to be scared.
If anything, I felt like laughing.
"What are you doing?"
"You're laughing? Hey, let go. I should teach you a lesson today."
"Taesik, hold it. It's only until today anyway."
"Hoo."
Yang Taesik reluctantly lowered his fist.
"I'll see you later."
I'd never seen someone terrifying say "see you later."
Rakshasa weren't people, after all.
"Sigh, it's all my fault."
I sighed and watched Yang Taesik's back as he walked away.
He hadn't been hostile from the start.
On my first day, he was even friendly, saying we should get along.
But as I kept failing, his interest turned into contempt, and his friendly gestures quickly became beatings.
His goodwill hadn't been toward me, but toward the Cheongsin Lee family name.
"Coming back like this, I actually admire my younger self. Enduring all that humiliation at such a young age."
Maybe that was why I couldn't give up.
I had learned painfully that powerless authority becomes a target of ridicule.
"Let's train."
There was much that needed to change.
Most lessons were held outdoors.
They taught the basics needed for martial arts—physical training, attack and defense, falling techniques, and footwork.
Since the academy had been created to raise his son into a Sage, Yang Geumho personally taught Yang Taesik's class.
Short hair and a large build.
Yang Geumho looked every bit like a soldier.
"Straight punch in place!"
At his command, fists shot forward in proper form.
"Roundhouse kick!"
At the next shout, feet lashed through the air.
After all the forms were done, criticism flew without fail.
"What a joke. Hey, look at that guy."
"What's the difference if you do it slowly?"
Ignorant brats, babbling without knowing a thing.
At this age, form mattered more than anything.
What we were learning now was the foundation of foundations—everything had to be perfect.
If you didn't learn it properly from the start, you'd regret it forever.
'And many things end up changing.'
To fix even one bad habit required twice the effort.
So even if it looked slow, it was important to engrave perfect movements into the body from the beginning.
They were too foolish to know that, hence their nonsense.
As I worried inwardly about their shortcomings, Headmaster Yang Geumho approached.
"Lee Seoha. When is your father coming?"
"He said he'd arrive around the end of this lesson."
"Is that so? Let's go to the headmaster's office together."
"Yes."
The moment had finally come.
By the time we reached the office, my father, neatly dressed, was waiting at the entrance.
After guiding us inside and offering seats, Yang Geumho began the conversation.
"Please, sit. Shall I bring some tea?"
"No, thank you. I have an appointment today, so I need to leave soon."
"I see. Then since this isn't pleasant news, I'll get straight to the point. I think it would be best if your son doesn't take the promotion exam."
"Is that so?"
My father replied calmly, his expression unchanged.
Perhaps he was trying not to show disappointment in front of me.
"It won't be easy to hear. But it shouldn't be denied either. Warriors are deployed to countless missions, and those without skill don't just die themselves—they get their comrades killed too. I know this better than anyone, because I've experienced it firsthand."
After a brief pause, Yang Geumho revealed his true thoughts.
"Seoha doesn't have the aptitude to be a warrior. It would be better for him to quit now and look for another path."
For someone dreaming of becoming a warrior, it was practically a death sentence.
But my father simply sipped his tea, saying nothing.
He was probably gathering his thoughts.
'This time, don't step in.'
As I grew older, I had wondered what my father had felt at that moment.
Back then, I was young, proud, and thoughtless, unable to accept the headmaster's words.
I made a scene, insisting I would never drop out, leaving no room to observe my father's reaction.
I had simply assumed he was disappointed.
'What will he say this time?'
Will he get angry with me?
Or will he accept the headmaster's suggestion, disappointed in his son's inadequacy?
Either way, I wanted to see my father's reaction.
After a brief silence, my father finally spoke.
"That doesn't seem like something for you to decide, Headmaster."
"Pardon?"
"It's Seoha's life. Others shouldn't interfere."
My father turned to look at me.
"Seoha, what do you want to do?"
A calm voice, not raised.
And in his eyes, I could clearly see his feelings.
'…So that's how it was.'
I had thought his blank expression was to hide disappointment.
That he was deeply disheartened but chose not to show it.
But that wasn't it. It had been my misunderstanding.
Only now did I face my father's true feelings.
"What path do you want to take?"
His words about it being okay to be late weren't consolation.
They were unwavering trust that his son would reach his goal.
And an expression of paternal love—supporting him to the very end, no matter what path he chose.
Accepting the feelings of my father that I couldn't face in the past—
"I will..."
With the push that urged me to walk forward with all my strength—
"I'll take the exam."
I stepped firmly toward the first rung of my plan.
"Haa..."
Yang Geumho let out a deep sigh.
Yes, it must have been an answer you didn't like.
"Lee Seoha, the promotion exam is a performance in front of parents. Don't embarrass yourself—quit now. You can't even memorize all the movements."
"I'll memorize them starting now."
"There's only one month left. Just one month."
"That's enough."
When I spoke with conviction, my father backed me up.
"That's what Seoha wants."
Yang Geumho clicked his tongue in irritation.
"…Tsk. Then there's nothing I can do. Very well. I'll keep that in mind."
"Thank you for considering it."
And just like that, the conversation that once turned into chaos ended uneventfully.
As we left the office, my father suddenly ruffled my hair.
"You little punk! Then you should've worked harder in the first place! What is this? Hahaha."
"Hey, I did try, in my own way. In my own way. Well, I'll really work hard from now on."
"Good. I'll be there to watch, so you'd better do well. Got it? You talked big."
"Of course."
How would a parent feel if their child was humiliated in front of others?
Would they be angry at an unprepared child? Disappointed?
No.
Most would be sad.
Their hearts would ache as if torn apart.
They'd blame themselves, thinking it was their own inadequacy as parents.
I didn't know that when I was young.
Blinded by my own pain, I failed to see my father's anguish.
'This time, it won't be like that.'
Because not repeating history includes my family's future as well.
"One month. Just one month."
It wasn't long, but it was enough.
I had trained the basics daily even before regression.
"I'll do it properly. Properly."
A father who had lived a life filled only with disappointment because of me.
So in this life, I would give him nothing but joy.