The reason for saying he'd stay on this island for two days before was simple.
That was how long the tailor proprietress needed to complete her work.
For an ordinary person without special abilities to custom-make clothing according to customer specifications in just two days.
Even if the clothing design wasn't too complex, it was still quite impressive efficiency.
It could only be said that anyone who dared open a tailor shop on the Grand Line really had some skills.
Still at that same open area from before.
"You have many problems. Solving them all in a short time isn't very realistic."
Ace wasn't the type of stubborn character after all.
After Naruto had convinced him through reason, he finally acknowledged his own inadequacies.
"Your fruit ability development isn't sufficient yet."
While saying this, Naruto simply demonstrated practically, forming hand seals.
Then, under Ace's incredulous gaze, he spat out a huge fireball.
The trees struck by the fireball instantly burst into flames.
"The most basic attack method of flames is burning, but don't forget. High temperatures are also a form of attack."
With that, he continuously increased his chakra. The range and flame temperature of the Great Fireball Technique kept rising.
The surrounding air temperature instantly increased, and the light became somewhat distorted.
Even as a Flame-Flame Fruit user, when not activating his ability, Ace's perception of flame temperature was the same as an ordinary person's.
"Even hot air, when inhaled into the lungs, can cause strong destructive effects. Don't limit yourself to only hitting enemies with direct attacks."
After saying this, Naruto turned around, only to see Ace with a completely stunned expression.
"Hey, hey! Snap out of it."
Ace, after being knocked on the head, quickly came to his senses and looked at Naruto incredulously.
"Naruto-uncle, that ability you just used..."
He hesitated to continue.
Could Naruto also be a Devil Fruit user?
"This? This is ninjutsu. There are plenty of people on the seas who master similar powers."
Just among the people Naruto knew, there were quite a few who could produce powerful flame attacks.
"Don't think only Devil Fruits can achieve such effects. Did you remember everything I just said?"
Seeing Naruto's raised fist, Ace instinctively covered his head and nodded.
"Good, then I'll continue."
"Don't over-rely on your fruit ability. Haki is the foundation for battles between the strong."
If one only had powerful fruit abilities while neglecting Haki training, enemies could easily exploit weaknesses.
"Your body can turn into flames. Get used to incorporating Haki into your attacks."
Seemingly intangible flames could naturally also be imbued with Haki.
While this wouldn't increase the flames' temperature, it could enhance the destructive power of attacks.
While saying this, Naruto was also thinking about whether he could incorporate Haki into ninjutsu.
For example, Conqueror's Haki-wrapped Wind Release Rasengan?
He'd try it next time.
"Also, don't get careless just because you're a Logia user."
Reaching out to knock Ace's head again. He tried to dodge but couldn't.
"Get used to using Observation Haki instead of 'sight' to observe enemy attacks."
"Just like I said before, since elementalization can be countered by enemy Haki, you can completely disperse part of your body after predicting attacks."
With that, he casually swatted at Ace's head again.
Ace learned and applied immediately, turning his head into flames and dispersing it beforehand.
"That's right. You're not too stupid."
After saying this, Naruto took off his outer coat and stretched his muscles.
"Alright, the basic knowledge explanation is complete. Advanced Armament Haki techniques and Conqueror's Haki coating skills can't be learned in a short time."
"When you return to Whitebeard's ship, have him teach you. If he hasn't gotten too old to move."
Hearing this, Ace opened his mouth to say something again, but after being glared at by Naruto, he behaved.
Perhaps not so well-behaved. After turning around, he was still silently muttering things like "Pops is the strongest."
Sigh, a guy who won't grow up.
Naruto felt somewhat helpless, then seriously said to Ace:
"After saying so much, it still comes down to practice."
"Come on!"
With that, Naruto once again emanated Haki.
"Don't worry, even if you get injured, I'll heal you."
Ninjutsu technology, shocking to the heart.
What followed was intensive training.
Even though Naruto had already pointed out many of Ace's shortcomings, the gap between Ace and Naruto was still enormous.
However, compared to his previously flaw-ridden appearance, this was much better.
It could only be said that this kid's combat talent had indeed inherited from his father.
So really, Whitebeard, you're truly hindering this child's growth!
Thinking this, Naruto's attacks on Ace became even heavier.
Time quickly passed another day.
Naruto's clothes were completed, and it was time to part ways.
After healing Ace, who had been beaten down and was gasping on the ground, Naruto withdrew his hand.
"Not bad. You're quite talented, kid."
The very talented Ace just gave Naruto a look.
"Why does it sound so awkward when you say that?"
"Alright, you should continue completing your business too."
With that, Naruto looked deeply at this kid whose birth he had witnessed, then suddenly said with deep meaning:
"One last piece of advice."
"If you discover you've stepped into an enemy's trap, don't foolishly fight them head-on."
"In such situations, even running away isn't shameful."
Ace disagreed with these words. He wanted to argue, but was interrupted by Naruto's next sentence:
"Think about those who love you and those you love. If you died at an enemy's hands, how would they feel?"
Hearing this, Ace fell silent.
Afterward, Ace still left. Whether he took Naruto's words to heart, no one knew.
But when Naruto watched him speed across the sea surface on that flame-powered single-person boat, a thought arose in his mind.
What a good thing...
Recalling his various previous experiences, Naruto also developed the idea of getting such a specially powered ship.
There was no helping it.
Sea Kings couldn't be encountered at all times, and riding ordinary ships was too slow.
Thinking this, Naruto had already determined his next destination.
The shipbuilding island closest to here is Water 7. It was also on the way.
It was said that Captain Roger's Going Merry was built there. Surely making a single-person vessel that could be driven by wind or other power sources wouldn't be too difficult?
Sharpening the axe won't delay chopping wood.
There was still a long way from here to the New World. This time he'd go through the Sabaody Archipelago.
Speaking of which, he hadn't seen Uncle Rayleigh in quite a while either.