A timber boat drifted quietly down the river, its cargo—neatly stacked lumber—resting heavy on deck. Onboard, Baek, Taishi, and Moon Soo sat in silence, as they navigated over a river spanning hundreds of miles.
The boat was simple—no engine, just oars and paddles . But no one was using them.
Why? Because none of them needed to.
Despite that, the boat moved steadily against the river's current.
"Where is the driving force, you ask?"
You thought it was magic?
But it was me, Jin Hoo!
Rope tied one end around my waist, the other secured to a bow cleat, anchoring the boat as I swam through the river, acting as its motor.
Every day, I pulled the boat over twelve and a half miles (20 km).
It felt like hell! I couldn't even rest when I wanted to. If I hesitated, even for a second, or took a break, the current would drag me back. But the effect this training had on my body was overwhelming!
Baek: "The kid seems to be doing rather well, don't you think, Grandmaster?"
Master: "Yes, it's impressive. His relentlessness has helped him a great deal."
Baek: "I agree. He's relentless. Swimming at this speed while carrying 1,630 lbs. (740 kg)—impressive, to say the least."
Moon Soo: "Would you like some more tea, Grandmaster?"
Master: "Yes, yes. Pour some for Baek too, and pass me that pork belly while you're at it."
"Wow. These guys are having a daily picnic while I'm out here wrestling with this bitchy river,Shit. "
"at least pass me a bite or two!"
This felt like eternity, but somehow, I have finished my training for the day!
Six months ago, before I started swimming, my routine was simple: I'd take a bath after training and eat dinner. But now, it's completely different. I sleep as soon as I get back home, then bathe, eat dinner, and sleep again. The toll this training takes on my body is so severe that I don't even have the energy to bathe before sleeping. I can't do anything after that.
To give you a sense of what i have accomplished the fastest Olympic swimmer reached 5.55 mph, without carrying anything. Here I am, swimming at 8 mph while hauling 750 kg and fighting a 2 mph current. If there were no current, I'd be at 10 mph. Twice the speed of a pro swimmer—on a good day.
As you've probably guessed, this is superhuman. I don't even know how training got me here.
But one thing's for certain: soaking your body in a bath after a long day of work feels so good!
"Hey, kid, don't spend too much time soaking in the water!" Baek called, tossing me a hexagonal stone.
I caught it and replied, "Sure, I'm done anyway!"
Every time before getting out of the bath, Baek would give me a hexagonal rock. This rock is incredibly strong, unbreakable even if you hammer it all day long, back in my old world.
But me? I crush it with my bare hands every day to use the fluid inside.
I've only recently been able to do this, and apparently, the liquid purifies your life energy. They say if your life energy is clear of impurities, you can boost your efficiency in tasks that require mental focus.
It seems to be a training for dungeon puzzles, since they usually require five people working together to solve.
If you want to solo a dungeon, you either do what I'm doing or survive the traps like some overpowered isekai protagonist.
Even though I'm technically an "isekai protagonist" now, I don't think I'll ever be OP in the world of Iron and Ashes.
I don't think I am ever allowed to be op-
"Time to get out of the bath, I guess."
I grabbed a change of clothes and headed to the living room. The food was the same as always, but now, it had doubled in quantity.
On the table now laid:
Bowls of steaming ginseng chicken soup
Grilled short ribs glazed in soy and garlic
Stir-fried tofu with shiitake mushrooms
Spicy braised fish with daikon and green onions
Roasted duck brushed with honey and forest herbs
A large pot of multigrain rice in the center
Surrounded by small dishes of pickled radish, kimchi, black beans, and salted anchovies
And it didn't just look good. It tasted divine.
After gobbling up a mountain of food in just 30 minutes, I bade everyone goodnight before making my way to the bedroom. Along the way "Hey kid ? Tomorrow there will be a test, it will decide whether or not you are ready for the next phase!" said master.
I replied "yes master I will be ready!" before rushing off to my bed and falling asleep.
THE NEXT DAY!
The test? A success!
Running along the bottom of the riverbed, I covered 1500 meters without stopping, all in under a minute—and I did it without taking a single breath.
Conclusion of my training: An overwhelming increase in physical abilities and stamina, reaching a superhuman level. With the test behind me, it was time to move on to the next phase of training.
Jin: "How strong am I now, Master?"
Master: "Hmmm, you're as strong as a D-rank knight, I'd say."
Jin: "Holy molly, are you serious? I'm that strong after just 8 months?"
Master: "Yep, but you'd still lose to a 10-year-old trainee who hasn't even accepted his knighthood."
Jin: "Okay, okay, stop the slander and tell me—what's the next training all about?"
Master: "The next phase, kid, is control and precision. You'll learn how to be as precise as a 'dragon mantis'!"
I wasn't sure what a "dragon mantis" was, but I knew enough about mantises and dragons to guess it had to be something badass.
I was handed a pair of iron chopsticks and told to follow Master on what seemed like an hour-long journey. I had been warned that the regions around here had very different vegetation, and they weren't kidding. We passed through rocky mountains, active volcanoes, and snow-covered lands, all divided by system of rivers.
Finally, we reached a forest of tall, sleek trees, the kind you might call "deciduous but elegant."
We rested there for a moment before...
Master: "Grab the chopsticks, kid, and do as I say."
He picked up his own chopsticks, and we both faced a tree, ready for whatever was coming next.
Master: "These are Po trees. The gravity here exerts at least twice the force you're used to, and there's no air resistance in this region. So, the leaves fall much faster than anything you've seen in your world."
He gave a sharp look at the tree.
"The training is simple—to catch them before they hit the ground. Just watch and learn."
Master continued to kick the ground, sending three leaves falling at once. They were fast, and without my previous training, they would have been invisible to me.
He grabbed them one by one and asked, "Why do you think it took me three swings to catch them when I can do that with just one?"
It was a valid question. After all, if someone can see all of them falling in slow motion and is fast enough to react, why would Master—who always says efficiency is what matters in a battle—need three swings instead of just one?
Jin: "Because you wanted to show off three cool moves instead of just one?"
Master:
"..."
"I'm going to pretend you didn't say that."
"Try again."
After spending five minutes thinking for a valid answer and observing the black residuals in the air, I finally answered:
"Because the leaves are explosive once they leave the branches, and you have to catch them one by one since they might explode if they're too close to each other? Not to mention, they could explode if you apply too much force, which is why you brought me here to train, right?"
Master:
He blinked once, then let out a quiet whistle.
"Not bad, Jin. Not bad at all. That brain of yours might actually be more than just decoration."
Jin:
"What? Decoration?"
Master:
"Now, now—let's get to the training. Since you've managed to explain it to yourself, I won't waste my breath."
He pointed toward the tree.
Master:
"You're going to catch the leaves of a dying tree—those are the only ones that are explosive. The forest naturally gets rid of them, but you'll make use of it. Not all the trees do this, only the ones at the end of their cycle."
He smirked.
"Your job? Catch them before they hit the ground. Try to keep as many as your limbs intact, alright ?"
Jin:
I stared at him, deadpan.
"Haha. So funny, Master."
Jin (narration):
I approached the tree reluctantly to start my training, I kicked the ground just as master did but forgot that I was much stronger than before and as every action has an equal and opposite reaction, instead of three leaves came in 20, in my mind I exerted enough for at most two of them, but nope-the twenty or so leaves blew me out the forest effectively ending my first "Explosive Training" without a "T".
The rest of the week ?
Just catching leaves while exerting enough force not to let them slip, while also preventing them from exploding. Doing that for five of them simultaneously, every second. On top of that, I had to gently place them on the ground—without triggering an explosion.
To put things into perspective, that would mean catching around 1,500 of them in just five minutes.
What made this different from the last training was that I had more failures than successes. I couldn't even catch 50 of them per minute—meaning catching just one out of five every second was already a struggle. The only good thing was that I got a two-day break every week.
I used the 2 days for self training by catching normal leaves with regular chopsticks and return to the explosive ones.
The more time passed, the more flustered I became, even though I was much better
This wasn't the first time I had experienced this. The solution was simple: calming down and trusting the process.
In the end, the training would be a rewarding experience.
~ 4 Months Later ~
Standing on a tall wooden staff, holding chopsticks twice as large as before, I faced a Po tree—much taller than the last one. Master struck the ground, releasing tens of leaves per second. The danger was that if one of the leaves exploded, I would fall from 50 meters above. But I was confident that I could exert just enough force on each leaf to catch it.
I succeeded.
Master:
"Good job, Leaf Slayer. The trees will be grateful for your service."
We headed home. It was the last day before starting combat training.
Master told me I'd be focusing solely on staff combat, since we didn't have much time.
I had no idea what he meant by that, though. After all, we'd only been training for a year up until now.
"Didn't you say we had at least two years for training? I've accomplished this much in one year—how much longer could combat training possibly take?" I thought to myself.
The answer to that question was clear: dungeons are dangerous, and maybe it was a high-ranking one.
But that wasn't the real answer. The real answer was: "The enemy had made their MOVE!!!"