Besides Devil Fruits, the most popular power system is Haki.
What is Haki?
Haki can be interpreted as a mysterious ability that allows its user to utilize their own spiritual energy for various purposes.
Haki is divided into three categories: Kenbunshoku Haki, Busoshoku Haki, and Haoshoku Haki.
Kenbunshoku Haki users can predict their opponent's intentions, sense the desires of all living creatures around them, and even see into the future if they reach an advanced level.
Busoshoku Haki users can enhance their attack power, harden their bodies, and reinforce their weapons.
Unlike the other two types of Haki, Haoshoku cannot be learned through training and is only possessed by those born with the spirit of a king.
Haoshoku Haki is the rarest form of Haki, possessed by only a few people in the world of One Piece. Its most basic function is to cause those with weaker wills to collapse.
"It feels like being drunk..."
At this moment, Eiji's consciousness was being assaulted by Kong's Haoshoku Haki.
The other party planned to defeat him without a fight to minimize damage to Mary Geoise.
"Your will is weaker than I imagined. My expectations of you were too high."
Seeing him stagger, Kong shook his head in disappointment.
"..."
Just when Eiji couldn't bear the mental assault of Haoshoku Haki, suddenly, his Six Eyes shone brighter than usual. Instantly, the momentum weighing on him vanished.
"Hm? Is your will getting stronger?"
His Kenbunshoku Haki always focused on Eiji. Kong immediately noticed the change in him.
However, a more surprising scene emerged.
*CRUSH-BANG*
A strong momentum equal to his own appeared from his opponent.
"What?! The awakening of Haoshoku Haki! Who is this young man really..."
The clash of two Haoshoku Haki produced a stunning shockwave.
Previously, the Marine officers were unaffected by Haoshoku Haki because Kong only targeted Eiji. However, the situation had changed. Eiji didn't care about their fate; his newly awakened Haoshoku Haki spread and expanded in all directions thanks to Kong's stimulation.
*BUK* *BUK* *BUK*
In the next second, people with weaker wills would collapse within the radius of Eiji's Haoshoku Haki.
Only Marine officers ranked Rear Admiral barely maintained consciousness. Even so, they couldn't stand steadily and were forced to kneel on one knee.
"There are already many Haoshoku Haki users. This world doesn't need another one."
Busoshoku Haki enveloped both his hands, and Kong attacked forward.
But his fists stopped several meters from Eiji, just like before.
'This isn't an invisible barrier, but more like my punch keeps advancing and can never reach him.'
Facing this strange phenomenon, Kong immediately analyzed the sensation he felt.
After that, he increased the power of his punches and launched a series of deadly strikes.
The result was the same; Infinity slowed his attacks to the point they never landed.
"Thank you, Kong. Seriously, you're a good teacher."
Finally, Eiji became aware after the Six Eyes helped him master Haoshoku Haki.
In the span of a minute in his mind, he understood the reason for the awakening of Haoshoku Haki even though he was not a native of the One Piece world.
It should be noted, Six Eyes can see the flow of Cursed Energy, empowering their bearers with the ability to read someone's Cursed Techniques and determine their function.
The source of Haki's energy is Spiritual Energy, which is a power possessed by everyone in any world, including Eiji.
Cursed Energy and Spiritual Energy have unique characteristics; both are metaphysical.
The basic requirement for a Jujutsu Sorcerer is to be able to see Cursed Spirits, which are metaphysical beings. Eiji, as a bearer of Six Eyes, has superior abilities in metaphysical matters.
Six Eyes analyzed Kong's Spiritual Energy when he activated Haoshoku Haki, analyzed it, studied it, and directly applied it to the bearer!
"As my thank you, I have a gift for you."
"Stop!"
Kong's pupils contracted sharply as he glimpsed the future through Kenbunshoku Haki.
"..."
With Infinity in place, Eiji ignored Kong's increasingly fierce punches.
Raising both hands above him and starting to spin, simultaneously, a blue mass quickly formed in the air and sucked up everything on the ground.
"Everyone, get away!"
Seeing his efforts to stop the other party fail, Kong shouted loudly, warning the Marine officers around him.
Unfortunately, many of them were unconscious due to the previous impact of Haoshoku Haki.
"It's too late. I hope you like this, Kong."
Unaware of the thin smile on his face, Eiji shot Blue into the sky over Mary Geoise.
"Cursed Technique Lapse — Maximum Output: Blue."
A tremendous suction force pulled everything within a 100-meter radius into Blue.
Concrete floors ripped from the ground, buildings collapsed from top to bottom, and people were sucked in.
All of it was sucked and destroyed by Blue like a black hole.
"What the hell is this? Hurry, save me or I'll shoot you dead."
"How dare he do this to the Tenryuubito! That person must be executed."
"CP-0, come quickly!"
Not only Marine officers but also unlucky Tenryuubito within Blue's range were the same.
CP-0 used Geppo to approach the Tenryuubito, then took them away from the suction area.
But not all Tenryuubito managed to escape. Blue's Maximum Output was astounding. Of the five Tenryuubito, two were sucked in and their bodies compressed to nothing.
"Brat, you have no way back."
Kong watched the scene grimly.
Tenryuubito are considered descendants of gods; anyone who dares to harm them will have Admirals personally handle the perpetrator.
There have already been cases of Tenryuubito being struck by people dissatisfied with their arrogance. The latest example is Monkey D. Luffy punching St. Charloss on the Sabaody Archipelago two years ago.
This is the first case of a Tenryuubito being killed. Moreover, they died in Mary Geoise, the center of the World Government!
If this news were to reach the public, the strong and noble image of Mary Geoise would be tarnished.
"You've committed an unforgivable crime, brat. Being imprisoned in Impel Down is no longer an option; you must die here."
After Blue in the sky disappeared, Kong stared angrily with veins bulging on his forehead.
Tenryuubito died before his eyes, and he couldn't do anything. This responsibility was on him; the Gorosei would surely be displeased.
"Kong, you talk as if you can catch me. I already said, no one can stop me from escaping." Said Eiji, stating a sea of facts.
"Your arrogance is so annoying. Watch how I break your invisible turtle shell."
After saying that, Kong infused Haoshoku Haki into his Busoshoku Haki-covered hands.
The black substance on his hands now turned into a shiny dark red accompanied by black lightning sparks.
A small number of very strong Haoshoku Haki users can infuse their bodies and weapons with Haoshoku Haki, in a manner very similar to Busoshoku Haki.
Kong once held the position of Fleet Admiral in an era of many legendary pirates like Roger, Shiki, Rocks, etc. Of course, his power was not weak.