Upon hearing Rayleigh's threatening declaration, Imu, who stood in the air, was not alarmed but rather delighted. He had long been looking forward to testing his skills against someone.
Although the memories of his predecessor gave him a clear understanding of his own level, and he often practiced his swordsmanship, memories were just memories, and practice was still practice.
Now, the 'Dark King' Rayleigh before him was the perfect test subject. Although he didn't know why this guy had come to Mary Geoise for no reason, since he was seeking his own death, he might as well help him along.
As the saying goes,
All men must die, but some need a little help!
As for the danger, it could only be said that a single top-tier fighter could not bring him such a rare feeling.
At the same time,
The air was once again filled with the sound of rapid slicing. Although the sound was not very loud, because there was no other noise and it was nighttime, it was quite clear.
Seeing this, Rayleigh roared, unleashing all his strength and Haki without reservation. Waves of energy burst forth without wind, causing his golden hair and the clothes on his back to flutter wildly.
"Dark Prison!!"
In an instant, his entire body swelled, his muscles and skin bulging, and his bones crackling with a series of explosive sounds. The muscles on his right arm expanded by a third.
As the long sword in his hand, shimmering with dense silver lightning, slashed forward, a brilliant blade light erupted, illuminating the entire area, eventually forming a huge crescent-shaped Flying Slash that vertically cleaved through the air.
The air along the path, under extreme pressure, turned into rolling waves of energy, forcibly pushing away all the invisible swords in the vicinity. The Adam Wood floor, worth billions of Beli, was cut deeply as if it were tofu.
In that moment, Mihawk experienced the same feeling as the spectators during the Marineford War in the original timeline, when they witnessed him challenging Whitebeard with a single slash.
The entire scene was filled with silver light. The three of them stared dumbfounded at the astonishingly huge blade light heading towards Nerona Saint/Lord Imu, including the Five Elders upstairs and the numerous CP agents in black guarding the castle gates.
"Huh?!"
However, this majestic, ferocious, and dangerously electric Flying Slash was flying somewhat slowly, and it was getting slower and slower, making everyone's expressions turn strange.
It was as if it had been slowed down by more than ten times, struggling to approach Imu in the air amidst the dense ripples of air.
After what seemed like an eternity, when it finally reached three meters in front of him, it exploded with relief, shattering into countless silver specks that scattered across the scene like starlight falling from the sky.
The scene was so beautiful, but Rayleigh's expression turned extremely grim, and his mood plummeted to the depths of despair.
"This is impossible..."
His move, 'Dark Prison,' would have required even Roger to use 'Divine Departure' to counter it. But... but this strange Celestial Dragon had simply blocked it with his hands behind his back! However, Rayleigh was still Rayleigh. As the vice-captain of the Roger Pirates, he had the ability to maintain basic rationality and calmness at all times, and he frantically analyzed the situation in his mind.
"Was that an air barrier?"
"The external release of Armament Haki!"
"How can there be such a terrifyingly immense level of Armament Haki in the world?"
At this moment, the 'Dark King' Rayleigh looked up at Imu under the full moon and realized that the latter wasn't floating using a Devil Fruit ability, but was instead 'standing' on an invisible layer of Armament Haki! This very fact left Rayleigh utterly shocked, as it surpassed his understanding of Haki.
Haki could indeed be released to affect the physical world, but such release was explosive and short-lived. To maintain it for a prolonged period, it had to be condensed on the surface of the body, known as 'hardening,' or wrapped around the body like a vapor, referred to as 'coating.'
In truth, this indeed surpassed the level of Haki mastery possessed by the top fighters of the outside world.
Over the past 800 years, Imu's predecessor had continuously honed, refined, and studied Haki, pushing Conqueror's Haki, Armament Haki, and Observation Haki to their near limits, and then fusing them into one.
From that point on, for him, Haki was no longer divided into categories.
The hardening, release, and internal penetration of Armament Haki; the vast range, aura sensing, action prediction, and future foresight of Observation Haki; the intimidation, pressure, and coating of Conqueror's Haki—all these traits were seamlessly integrated.
Coupled with the accumulation of experience over the years, the sheer volume of Haki had reached the limit of what the mind and spirit could contain, ultimately leading to a qualitative transformation.
Not only that.
Over the long centuries, Imu's predecessor had surpassed the level of a Great Swordsman, a realm he referred to as 'Sword Saint.'
Over the centuries, he had witnessed many exceptionally talented swordsmen, but only Ryuma of Wano Country had come infinitely close to this realm.
This was also the main reason why Ryuma was able to defeat the Marine Admiral of his time and was hailed as the 'God of the Blade.'
However, in the eyes of Imu's predecessor, Ryuma only truly deserved the title of 'God of the Blade' when he fully stepped into the realm of the Sword Saint.
Unfortunately, Ryuma lacked the ability to live eternally and ultimately succumbed to the decay of his mortal body over time.
Since then, Imu's predecessor had advanced further, combining his Way of the Sword with Haki to create these invisible Sword Auras that could appear anywhere within the range of his Haki.
Imu's predecessor called this 'Divine Territory.' "Ant, feel honored to die in this place. For you, this is the greatest glory and blessing of your life."
Imu's abilities were not complex, lacking any flashy tricks. Having personally experienced his own methods, his interest in Rayleigh gradually waned.
He intended to send this 'Dark King' to the true underworld in a spectacular fashion. Whether Rayleigh could become a king there was none of his concern.
[Zzzzzzzzzzz————]
In the next moment, Rayleigh, standing on the sphere representing the 'first half of the Grand Line,' saw countless golden lightning-infused Sword Auras gradually condense behind Imu.
Their numbers increased at a visible rate, and soon the night sky in all directions was completely covered by a dense sea of golden light.
Rayleigh's narrowed eyes could discern that the Sword Auras themselves were still invisible and transparent, only appearing intermittently under the flickering illumination of the lightning.
"Can these Sword Auras also be imbued with Conqueror's Haki? And the color is an unprecedented gold. This is truly a big mess~~"
At this moment, Shakuyaku's face flashed in his mind.
"If only I had known..."
[Swish swish swish swish swish swish swish!]
All the lightning sword beams transformed into incredibly fast golden flashes, like a torrential downpour under the moonlight. The golden wind carried an endless killing intent, completely engulfing, enveloping, and covering Rayleigh, who was swinging his longsword with all his might.
The silver lightning sphere was fiercely bombarded by golden lightning. Sword Auras tangled with each other, engaging in intense offensive and defensive exchanges. Lightning clashed, exploded, and dissipated continuously.
The court below, inscribed with 'Grand Line,' also began to crack and shatter, as if the full-scale battle between the two had caused the sea to churn and the sky to tremble.
After an unknown amount of time, the light sphere began to flicker incessantly. Drops of bright red blood splattered under the moonlight, only to be evaporated by a passing lightning flash, turning into a mist of blood.
Suddenly.
Mihawk and the others noticed that no new lightning Sword Auras were appearing in the air. As the last flash of lightning struck the ground, they saw that the 'Dark King' Rayleigh had already fallen to the ground.
His back, arms, and legs were pierced by invisible Sword Auras crackling with golden electricity. His eyes were in a dazed state, and the longsword in his hand was already broken.
"Roger... It seems my journey ends here. This... this adventurous life was truly wonderful."