The test limit of the Combat Force Device is 10,000.
With Rosen's combat force value of 260, it is impossible for him to exceed the upper limit of the device. However, not exceeding the limit does not mean that the device cannot be destroyed.
Using Armament Haki to penetrate the surface of the Combat Force Device, entering its interior, and destroying its internal parts.
That combat force value of 260 can still destroy a device with a test upper limit of 10,000.
Zephyr naturally saw this, which is why he was so shocked.
"I saw that you just mentioned that in addition to Hardening and Emission of Armament Haki, there is a fourth technique."
"Internal Destruction."
"So, when I released my Armament Haki, I tried to manipulate it to pass through the surface of the object and directly destroy the inside."
Seeing Zephyr's expression as if he had seen a ghost, Rosen could only explain.
"I only mentioned Internal Destruction..."
"You actually mastered the fourth technique of Armament Haki on your own?"
Zephyr was so shocked that his mouth hung open.
It was like casually saying "atomic bomb" to someone, and then the other person actually going and making an atomic bomb with their bare hands.
"That's about it."
"But it's not entirely my own achievement."
"If it weren't for your words about Internal Destruction, Instructor Zephyr, I wouldn't have known that Armament Haki could be used in this way, so Instructor Zephyr is still a good teacher!"
Rosen nodded slightly.
"..."
When Zephyr heard this, his old face suddenly turned red.
He had always been very proud of his teaching ability.
After all, he had trained three Admiral candidates, and they were monsters who would definitely become Admirals.
If anyone else said that he taught well, Zephyr would definitely accept it calmly.
But facing Rosen, Zephyr was too embarrassed to say that it was because of his good teaching.
He knew very well that even if a random Marine who knew Haki came to teach Rosen in the New World, the final result would be no different from what he, Zephyr, taught.
Rosen's talent for developing Haki had already reached a level where he could basically ignore the teacher's level.
A random Marine could teach him, and Rosen would learn Hardening, Imbuement, Emission, and Internal Destruction in one class.
The future leader of the Navy teaches him, and he would still learn all four in one class.
"What's wrong?"
"Is there a problem?"
"Did you accidentally hurt yourself while practicing Armament Haki?"
Zephyr was about to say something, but saw Rosen frown slightly, so he hurried forward and asked with concern.
This was a future Admiral, no, a future potential Fleet Admiral!
If Sengoku knew that he had injured such a potential future fleet Admiral while teaching, he would probably come to the Naval Academy to smash him with the Buddha Palm.
"It's not an injury. I just had a sudden thought."
"Can't Armament Haki destroy from within? If the enemy also masters this technique and attacks me this way, how should I respond?"
"Instructor Zephyr, what do you think?"
Rosen shook his head and asked Zephyr for advice.
He thought of the fight between Kaido and Luffy.
Both of them had mastered advanced techniques of Armament Haki such as Internal Destruction, but when facing each other's attacks, they seemed to only choose to take the damage head-on?
"The only thing that can counter Armament Haki is Armament Haki."
"If the enemy uses a technique like Internal Destruction, you can only release Armament Haki to counteract it before the opponent's Haki touches your body. But battles are ever-changing, and if you are attacked by the enemy, it means you can't react at all. How can you have enough time to mobilize a completely equal Armament Haki in an instant and then release it to counteract it?"
"If you can do that, then you have enough time to dodge the attack altogether and not get hit."
As a former Admiral, Zephyr answered Rosen's question without hesitation.
"So, we can only take the damage?"
Rosen's brows furrowed even more.
What he ate was the Arms-Arms Fruit, not the Azure Dragon, nor the Nika Fruit.
His health bar isn't that thick, and his defense isn't that durable.
"Have you forgotten?"
"What was the first thing I said in class?"
"It's not enough to possess the Haki that overrides everything. You must also possess the physique of a monster and the will of Iron."
Zephyr glanced at Rosen.
The meaning was self-evident.
The monster's physique was meant to withstand the damage caused by Internal Destruction.
"In the end, we still have to endure it."
"Instructor Zephyr."
"Is there no other way?"
When Rosen heard this, his brows furrowed even deeper.
"Unless you don't care about the consumption of Haki during battle and use it to Harden your entire body at all times. But if your Haki is dispersed throughout your body, your defense will inevitably decrease."
"The enemy only attacks one area of your defense, and it can still break through."
"Even if you do this, you might lose to an opponent you could have defeated because you consumed too much Haki."
Zephyr shook his head:
"Don't think about it. You worry about the enemy's Internal Destruction, and the enemy also worries about yours."
"Instead of worrying about these things, it's better to train your body and physical skills well."
"In this way, you can severely injure the enemy before he attacks you."
He spread his hands.
Rosen secretly shook his head, feeling that Zephyr's method wouldn't work.
It's fine to bully weaker opponents.
When facing an opponent of the same level, who can guarantee a one-hit kill?
Take Kaido for example.
Who can clear Kaido's health bar with one strike?
Big Mom?
Shanks?
Or Whitebeard?
The three of them together might be able to do it.
"Don't think about these things."
"Anyway, as far as I know, there is currently no method on the Grand Line that can effectively resist Internal Destruction. Hardening, or Emission are all ineffective."
"Neither the Four Emperors nor the Admirals can effectively defend against Internal Destruction attacks..."
Seeing Rosen's frown, Zephyr was afraid he would get stuck in a mental block, so he shouted at him.
"Hardening and Emission are all ineffective."
"In that case, can I create a Haki technique specifically for defending against Internal Destruction?"
"Instructor Zephyr also said that only Haki can counter Haki, and techniques such as Hardening and Imbuement were created by our predecessors. In other words, there was no Internal Destruction before, but someone later thought of it, so it came into being."
Thinking of this.
Rosen's consciousness began to sink, and he poured the Armament Haki into his body, rolling it into a ball and flattening it, trying to figure out a shape, trying to figure out a technique that could specifically counter the enemy's Internal Destruction.
As the Armament Haki continued to change in his body, his mind gradually emptied and completely merged with the Haki.
No one noticed.
His Haki actually began to slowly flow into his blood vessels, circulating throughout his body along with his blood flow.
[You have an extraordinary understanding. You have combined the four techniques of Armament Haki with Haki Ultimate Intention to create an innovative and unique skill for Armament Haki: Blut Vene (Calm Blood Dress).]
[Blut Vene (Calm Blood Dress): Using the absolute control of Armament Haki granted by Haki Ultimate Intention, inject Haki into the blood vessels to transform it into substantial defense, greatly improving defense inside and outside the body, and can effectively defend against Internal Destruction.]
(Requires Haki Ultimate Intention. If others practice it, it will cause permanent damage to blood vessels throughout the body.)
…
Suddenly.
A line of information appeared in his mind, waking Rosen from his deep thought.