Watching Aizen rush forward first, braving the oppressive spiritual pressure, Naraku Sora was momentarily stunned.
'Wait, seriously, man?'
'You've always been the refined and gentle type. Why did you suddenly switch to a fighting style just like mine?'
'This isn't right.'
'This is the world of Soul Reapers; losing your style points is a death sentence!'
Under the washing tide of spiritual pressure, the spirit particles within his field of vision began to warp, and the air vibrated violently. Arturo had completely transformed, looking like a king descending upon Hueco Mundo.
He had expected that after completing his blade release, these two Soul Reaper brats would either run away or show faces twisted in terror.
But reality dealt him another stinging slap in the face.
The Soul Reaper youth who seemed mild-mannered on the surface was the first to charge at him. Although the expression on his face remained unchanged, the fanaticism in his eyes was unmistakable.
It was as if a starving man were looking at a delicious meal.
It was absurd.
However, seeing that agonizingly slow Shunpo and the slash that lacked any sense of intimidation, a layer of undisguised arrogance flickered in the depths of Arturo's eyes.
'Before my Resurrección, I could let a move like that slide. But now, even after I've risked the side effects of soul damage to complete my release, you still fight like this?'
'Are you looking down on me?'
Arturo raised his spine-like blade and swung forward without warning, catching Aizen exactly where he appeared.
Metal clashed against metal, and a deafening shockwave erupted.
The silver-white sand sea burst open, a massive fissure appearing like the maw of an abyss, threatening to swallow all the surrounding white sand.
The exaggerated display made even Naraku Sora click his tongue in amazement.
In his understanding, a Great Hollow's Resurrección and a Soul Reaper's Bankai shared similar forms of expression, but in reality, they were worlds apart.
A Resurrección required sealing the Hollow's core into the shape of a blade; it was essentially a return to the Hollow's original power.
But in terms of combat performance before and after the release?
They were in completely different leagues, not even on the same dimension.
If Naraku Sora could previously rely on his ultra-high growth potential plus Hollowification, Shikai, and other means to trade blows with Arturo...
Now, facing him again felt like he was coming up short.
On his own, he was simply not enough to confront the released Arturo.
Fortunately, Aizen had taken the lead to hold the line.
Boom! "What?!"
Caught in the impact and sent flying by the sheer force, Arturo flipped his hand and stabbed his blade into the ground, forcing himself to a halt.
The arrogance that had been on his face vanished, replaced by an expression of disbelief and shock.
'What level of spiritual pressure is this?'
'Grade three? No, grade two?!'
'What is with these two guys?'
One had weak spiritual pressure but ridiculously high attack power, while the other had average attacks but spiritual pressure that was terrifyingly strong.
Could it be that after two thousand years, the Soul Reapers of today were all this abnormal?
Suppressing his internal suspicion, Arturo slowly stood up. The crimson wings on his back unfurled, and the air vibrated with a booming roar.
Sonido!
He left a deep, scorched trail on the surface of the sand.
He was as swift as a bolt of lightning.
In an instant, he crossed several hundred meters. Countless spirit particles gathered on his blade, making the already heavy spine-sword look even wider, like a massive pillar.
He smashed it down.
The long sword, swathed in spiritual pressure, appeared in front of Naraku Sora without warning.
"?"
'Aizen is the one beating you, so why are you attacking me?'
There was no time for thought as the spine-sword slammed down.
In a moment, Naraku Sora felt the roar of erupting spiritual pressure.
It was as if the sky and the earth were screaming in unison.
A majestic force hit him like a tidal wave. Even with his Zanpakutō held up to parry and redirect the force, he found it difficult to resist.
He was sent flying instantly, like a soccer ball hit by a power shot, spinning through the sky before crashing down and gouging out a deep, massive crater.
And that was only the beginning.
Arturo seemed to have locked onto Naraku Sora. He immediately took to the air, raised his right hand, and spread his fingers.
Cero.
Violent pillars of light fell like rain, frantically battering the sandy ground below.
One deep pit after another was blasted open, making the terrain look like the surface of the moon.
Under such an onslaught, there was no opportunity to counter. Naraku Sora was forced to use consecutive Shunpo to dodge.
A single mistake would mean being hit directly by a Cero.
It was only because he was incredibly durable that he could withstand this; had it been any other Soul Reaper, a single Cero would have been enough to blow them apart into a mist of blood.
Hideous ravines appeared within the craters. The slightly raised sand dunes collapsed cleanly under the powerful impact of the infinite Ceros, and the very topography changed.
Constant defense eventually leads to a lapse. A slight error in his Shunpo caused Naraku Sora to take a Cero head-on. Like a man hit by an artillery shell, he was buried deep beneath the sand sea as countless white sands instantly covered him.
"Dammit, seriously!"
Aside from Senjumaru and Yamamoto, this was the first time he had been beaten so miserably.
Beneath the silver sand, pitch-black spiritual pressure erupted, shattering the upper layers of the sand sea. His battered and bruised body surged out, healing continuously amidst the whipped-up gale.
His scorched skin healed in an instant. In a mere heartbeat, Naraku Sora was whole again and launched a formal counter-offensive against Arturo.
The released Arturo had indeed become much stronger, but that didn't mean he was unbeatable.
With the double buffs of Hollowification and Shikai, he could still go toe-to-toe.
He cleaved through a surging Cero with a single strike, the light splitting to both sides and splashing sand into the sky.
Naraku Sora bent his legs slightly, brewing all the strength in his body. Accompanied by a deafening roar, he launched himself into the sky using the recoil.
He went straight for Arturo.
Vajrayati was held high. Brilliant golden electric arcs coiled around the blade, their radiant glow dispelling the darkness of Hueco Mundo and even briefly suppressing the lone moonlight.
Arturo's eyes narrowed slightly. Just as he prepared to raise his sword to respond, Aizen's spiritual pressure suddenly appeared behind him.
"Bakudo #63: Sajō Sabaku."
"Hado #63: Raikōhō."
"Hado #73: Sōren Sōkaitsui."
There was no time to block Naraku Sora's attack; next on stage was the master of Kido—Aizen Sosuke.
Golden chains snaked and shot out like pythons, locking onto Arturo's figure and rushing toward the heavens.
With only a moment's distraction, he found himself caught in a pincer attack.
Arturo instinctively placed more of his attention on the Kido behind him.
In his mind, weak spiritual pressure meant the attacks couldn't be that strong. Even if there were exceptions, there would be a limit.
On the other hand, someone with strong spiritual pressure was different. Even if it was Kido cast without an incantation, it could potentially erupt with unimaginable power.
The moment the chains of Sajō Sabaku wrapped around him, Arturo flipped his hand and pushed his spiritual pressure defense to the limit.
Layer after layer of spiritual pressure stacked to form a shield, attempting to block Naraku Sora's slash this way.
His sword, meanwhile, hacked down at the incoming Kido.
The sound of clashing metal erupted, and countless sparks flew. The Sajō Sabaku, which had only a third of its power, was unable to withstand Arturo's strike.
But that split second of delay was enough for the other two Hado to arrive as scheduled.
The fusion of Raikōhō and Sōren Sōkaitsui erupted, whipping up a brilliant wave beneath the crescent moon that instantly painted the sky.
The momentum was grand, like a magnificent fireworks display.
Before the aftershocks could even fade, a hideous, demon-like grin appeared abruptly within Arturo's perception.
The electric arcs on the long sword in Naraku Sora's hand erupted with a surge, letting out a sharp sound like the cry of ten thousand birds, making one's scalp tingle and teeth ache.
It was as if he wasn't holding a Zanpakutō, but a descending bolt of lightning.
Previously, he had thought about combining his Secret Tradition: Ryusen with Kido to complete a technical update of his Ghost-Sword style.
But several attempts had yielded no results.
It wasn't until his battle with Enrakyoten, when he saw how it combined the powers of different Zanpakutō, that a spark of inspiration flashed in Naraku Sora's mind.
Since he couldn't fuse Ryusen and Kido for now, he would brew it in advance, accumulating the power of Kido within his Zanpakutō, and then strike with the strongest Ryusen slash in that state—
Thunderous Dragon Flash!
A roar that shook the heavens and earth erupted.
A crack appeared on the spiritual pressure shield that had been worn down by nearly half by Aizen's Kido. Instantly, it crumbled into pieces.
Arturo's eyes widened in shock, as if he were seeing ten thousand thunderbolts surging toward him.
A brilliant pillar of light erupted, piercing through the firmament in an instant and becoming the most dazzling sight on the battlefield.
The violent impact caused the sand sea to explode in layers. Gunsmoke and dust whistled and surged, while leaping thunderbolts connected the sky and earth into a single whole, and a brutal hurricane rose from the ground.
Boom!!
A sharp explosion rang out from within the light pillar. A figure was sent flying from the center, moving like an iron plow turning over the desert as visible waves rippled out through the gale.
From south to north, circles of air blasted open. Dragging a trail of lightning, Arturo carved a deep trench dozens of meters long into the sand sea before slamming violently into a raised sand dune, kicking up a massive wave of dust.
Watching such an exaggerated scene, Aizen wore an expression of surprise.
Because they often reflected on what they learned together, he knew Naraku Sora's strength very well.
Although Sora had never used Hollowification in their sparring matches, Aizen had a general idea of how it would perform.
But that slash just now had clearly exceeded his original upper limit.
If things continued at this rate, could he really keep staying ahead?
A sense of urgency inexplicably grew in Aizen's heart.
"Crawl, Iron Princess. The mud doll who never stops self-mutilating. Combine, repel, and extend to the ground. Know your own powerlessness."
A calm voice rang out amidst the whistling hurricane. The faint black light of Kido bloomed from his fingertips, deep and unknown, looking as if it had absorbed the moonlight itself.
It was still the Black Coffin—the technique he was best at and that served him best.
Aizen gazed at the sand dune not far away, his spiritual pressure locking onto Arturo's position from a distance, giving him not even a moment's respite.
The moment Arturo fell, a deep darkness rose from the earth. A vast torrent of spiritual pressure pressed down, and complex patterns were etched onto the iron walls.
In an instant, Arturo was sealed within.
Countless blades erupted inside the black sarcophagus, followed by the continuous sound of tearing flesh.
When the Black Coffin dissipated, the mangled Arturo was still standing upright, but he was covered in blood and barely recognizable as human.
The most serious injury among them was the one left by Naraku Sora's enhanced Ryusen.
It stretched from his right shoulder all the way to his waist. The gash was deep enough to see bone, nearly severing half of his torso.
Blood stained his pale face. His cold golden eyes stared at the two men nearby, and his indifferent voice slowly rang out.
"I have to admit, time is the deadliest weapon."
"Only two thousand years have passed, and yet the Soul Society has produced Soul Reapers comparable to Yamamoto Genryusai."
"In fact, they are even more formidable."
"I underestimated you."
"But at the same time, you have no understanding of what it means to be the Unfading King."
As he spoke, countless buds of flesh sprouted on his wounds. A level of High-Speed Regeneration that far exceeded the limits of known logic began to take effect.
As an existence that had nearly ruled the Soul Society, Arturo possessed a vital core ability besides absorbing the spiritual pressure of the defeated.
That was Extreme High-Speed Regeneration.
Unlike the regeneration of other Great Hollows, no matter how severe the injury Arturo sustained—even if his head were cut off—he could regrow it and be resurrected.
Even a small piece of remaining tissue could be fully restored.
And this was exactly why Yamamoto had chosen to seal him rather than kill him.
Watching the mangled body recover at high speed, an envious look appeared on Naraku Sora's face.
His own regeneration was strong, but compared to the completely illogical Arturo, it was still more than a little behind.
However, despite such a heaven-defying ability, Arturo failed to see even a hint of fear on the faces of the two people across from him. Instead, they were remarkably calm.
It was as if nothing had happened at all.
He frowned, somewhat confused.
As if sensing Arturo's confusion, Aizen took two steps forward. By now, the surrounding aftershocks had died down, and the dust had settled.
A calm voice rang out in the dead silence.
"Actually, even before setting out for Hueco Mundo, I had already considered this problem."
Aizen's indifferent demeanor caused a strong sense of unease to rise in Arturo's heart, as if something terrible was about to happen.
"Given Head Captain Yamamoto's temperament back then, why would he choose to seal a Vasto Lorde who had achieved natural Arrancarization beneath the Hill of Sokyoku?"
"Could it be that even a Demon of the Sword can feel mercy?"
"I understood perfectly the fallacy of that thought. Therefore, I changed my perspective. Perhaps it was because the enemy could not be killed that he had to settle for the second-best option: sealing."
"Later, this idea was confirmed during your battle with Sora. Your High-Speed Regeneration is completely irrational."
"Thus, I concluded that even if the two of us joined forces, we would be unable to kill you."
"So, the moment you were struck down by Sora, I used the Black Coffin to drive a self-created Bakudo into your body."
Arturo's face changed instantly.
The next moment, a spike appeared out of thin air, piercing directly through his chest.
As if it were a signal, countless spikes grew out of nowhere, dismantling the Hierro defense Arturo was so proud of from the inside out.
"This is impossible!"
Arturo, who had been calm until now, finally showed a hint of panic. He swung his blade at the spikes, producing a series of sparks.
Seeing that his attacks were ineffective, he ruthlessly tried to gouge out his own flesh.
"It's useless. The place I chose to plant it wasn't your flesh, but your spiritual pressure."
Aizen's words were meant to destroy his spirit. His calm tone felt like knives stabbing into Arturo's heart.
"At the same time, the majority of your spiritual pressure is being used for High-Speed Regeneration. This is an instinctive reaction that you cannot suppress."
"Therefore, the effect of the Bakudo will be pushed to its absolute limit."
Beside him, Naraku Sora had a strange expression on his face.
Should he say that the thought processes of scientists often show startling similarities?
If he remembered correctly, this kind of method was supposed to be used on Aizen by a certain salty fish, right?
But with Arturo as a prior example, would Aizen be on guard in advance?
Speaking of which, he seemed to have left that salty fish alone for too long. He wondered if that guy had taken the bait yet.
He'd have to go to Squad 2 and check it out after they got back.
Naraku Sora fell into thought.
"Gah..."
Amidst Arturo's desperate cries, the spikes gradually consumed him. Chains sprouted from within, completely sealing off his spiritual pressure.
A massive cross stood tall in the desert.
Seeing this, Aizen breathed a sigh of relief.
It was finally over.
Meanwhile, somewhere in Hueco Mundo, inside a massive nest.
A thin figure lay in a chair, wearing something resembling a pair of binoculars on his face. The corners of his mouth curled slightly, as if he were seeing a truly intoxicating scene.
"To think Arturo was actually sealed. How unexpected."
"What a unique existence. Beyond mere cleverness and talent, the unknown is what a scientist should truly pursue."
"I've remembered your scent, Soul Reaper—"