Bleach: Starting as a Vasto Lorde

Isane stopped in her attempt to heal Aizen. Golden threads formed around his vicious wound. The wounds closed right before her eyes, seemingly faster than the regeneration of Kaido.

“What…?” She blinked her eyes at yet another twist in a night brimming with them. Only then did she find the golden strings of the tree were connected to Aizen’s back. “The tree is healing Captain?”

The massive tree emitted no Reiatsu, as if it was a mere illusion. But it was real. As real as the Arrancar who injured Aizen. The mysterious nature of the tree simply made it hard to find its true owner between the Hollow and Aizen.

‘How are Hollows suddenly so strong?’

Comparing the Arrancar in armor to the grotesque Arrancar Kazuya previously defeated was like comparing a Seated Officer to a Captain; they were in separate leagues.

Aizen’s scorched Shihakushō spoke volumes; he was outmatched in the battle.

“Shinigami girl,” the Arrancar spoke in a distinctly feminine voice, yet it had a familiar allure to it. “Get lost. This is between me and this asshole.”

Isane pulled out her sword. “I will—”

Suddenly, the Arrancar glanced in her direction, pinning her down with her Reiatsu. Isane froze, feeling as if she was being eyed by the Soul King himself.

Aizen arrived before Isane, protecting her from the Arrancar’s Reiatsu. “Vice-Captain, can you return to the Soul Society and ask for Captain Commander to come here? Without him, we can’t take this Arrancar down.”

The hint of weakness in Aizen’s voice made her heart tremble. Even a Captain wasn’t able to combat the unnaturally strong Arrancar and needed General Yamamoto’s help.

‘Kazuya took down three on his own… he is a fool to join our squad.’

Isane clenched her fists, a determined light in her eyes. “Alright, Captain Sosuke. I’ll come back as fast as I can.”

The Arrancar in armor, whose voice carried a similar charm as Kazuya, lunged at Aizen, who also didn’t shy from a full-on brawl.

Their battle raged on in the sky, becoming a spectacle not even Isane could keep up from the sidelines. Sparks and embers flew as gauntlet-covered fists clashed with Aizen’s in the night's darkness. Each howling strike charred Aizen’s skin and burnt his flesh, but the damage recovered in mere moments.

Isane could hardly believe her eyes. The Hollow’s stance was open yet guarded, like that of a formally trained warrior. It felt like she was in the presence of a genius martial artist like Soi Fon.

Aizen, on the other hand, was calm and elegant as he traded blows with his opponent. The flurry exchange of counters and even more counters to those counters — it was a sight to behold even for a non-martialist like Isane. Aizen was a far more skillful fighter than she could’ve discerned from his gentle demeanor.

In fact, he was the superior martial artist between the two.

Yet Aizen was the one receiving injuries.

Everything boiled down to the Hollow’s berserk style of fighting; she dodged no attacks, no matter how deadly they were. Her armor absorbed every bit of punishment. Normally, Hollow fought to consume the other party or to survive, but the Arrancar in armor fought with the intent to kill her opponent. It was as if she harbored a deep hatred for Aizen and would stoop to any level to carry out her revenge.

Isane had never seen any Hollow act in this manner. Then again, she had never seen any Hollow having the ability to control people’s bodies. Today changed her entire perspective on the Hollow race as a whole.

‘This is a fight above me. I have to bring Captain Yamamoto here.’

With a heavy heart, Isane tore her gaze away from the intense battle and opened a Senkaimon door.

…

A surge of relief washed over Kazuya as Isane departed the battlefield. He would have to hurt Isane if she joined the battle. Fortunately, she thought things through and heeded Aizen’s request.

{Partner, we are halfway there… Just how much Reiatsu does this fucker has?!}

The crimson flames continuously tormented Aizen on top of the bone-crushing blows he dealt to Aizen. But his Reiatsu drained at a snail’s pace — slow but steady. He knew he would easily win if given enough time, but luck was not on his side.

Isane would return soon with General Yamamoto, and he didn’t want to waste any more time dealing with other captains.

“Afraid you can’t drain my Reiatsu now?" Aizen taunted Kazuya as they traded blows. “Your Resurrección — the tree — works by draining Reiatsu from your targets, doesn’t it?”

In just a short amount of time, Aizen had already figured out the ability of Kazuya’s Resurrección. It was this fearsome intellect that made Kazuya determined to finish the job today.

The lack of expression on Kazuta’s face once again disappointed Aizen. “Are you sure you can dally here? Tier Harribel is fighting a losing battle in Hueco Mundo…”

Kazuya paid no attention to Aizen’s attempts to distract him. Instead, he glanced at the tree and quickly cut off the strings attached to Aizen — a move that went unnoticed in the heat of battle.

Kazuya made his move before Aizen could notice; he drew back and conjured his Oppression ability. As he reached out towards Aizen, a cyan-blue Reiatsu immediately enveloped his right hand.

The ground beneath began shaking as an influx of Reiatsu filled the surroundings.

‘All or nothing.’

Aizen immediately used Shunpo to reposition away from the Reiatsu and egged Kazuya with a provocative gaze. “You are ready to ‘sacrifice’ the whole town just to kill a Shinigami you just met. Is that a worthy trade in your eyes?”

“My ability…” Kazuya shifted his gaze to the fading glow around his gauntlet. “It’s already reached you.”

As if on cue, the blood vessels in Aizen’s hands ruptured and sprayed blood. His hands fell to his side, numb and limp.

A painful gasp left Aizen’s lips. He stared at his bloodied hands with wide eyes. “You… concealed this ability.”

Nothing could’ve prepared Aizen for the manifestation of Kazuya’s Aspect of Death Oppression. The wild card quite literally crippled Aizen.

Kazuya shook his head. “I had to, because it consumes too much Reiatsu.”

Even after studying Aizen through his partial Resurrección ‘Visión del Diablo’, he had to consume almost all of his Reiatsu to penetrate Aizen’s defense and destroy all the blood vessels connected to his arms. That was Aizen with less than fifty percent of his total reserves. Kazuya’s entire spiritual energy wouldn’t have worked on Aizen at his peak.

Aizen was truly a monster.

Watching Aizen struggle with the awkward movements of his injured hands, Kazuya felt a surge of satisfaction. The sacrifice of expending so much Reiatsu was worth it. Not only did it hinder Aizen’s fighting capabilities, but it also caused chaos within his spiritual energy, disrupting its efficiency.

{Fuck him up. DESTROY HIM.}

Kazuya took a deep breath and rushed at Aizen. Left with barely functioning hands, the Captain had no choice but to flashstep away. A series of afterimages flickered as Aizen put more and more distance between himself and Kazuya.

He could use kicks to fight but that would yield no result against a berserker like Kazuya. It was better to stall for time than engage him in a straight-on duel in his condition.

“Don’t leave, Sweetheart.”

With a quick flick of his wrist, Kazuya maneuvered his golden strings and yanked Aizen to a halt, preventing him from escaping. The Divine Tree ensured that no matter where Aizen tried to run, he would always be pulled back.

Aizen glared at Kazuya, a hint of anger in his usually calm eyes. “What are you doing?! Have you considered the consequences of killing a Captain? You’ll be put on the highest bounty list and hunted to the end of the world.”

Undeterred, Kazuya closed the distance between them in an instant, using Sonído to move faster than the eye could see. His gauntlet-clad fist collided with Aizen’s face, shattering bone and sending shockwaves through his entire body. Blood gushed from Aizen's lips, staining what little was left of his Shihakushō.

“I can never rest easy with scum like you invading Hueco Mundo for power. You’ll die here today.”

“Scum? You low—”

But before he could finish his retort, Kazuya drew back his hand and landed a satisfying reverse-handed slap across Aizen's right cheek — a slap for causing so much chaos and suffering.

Flesh tore on impact, blood spraying outward in a grotesque display.

Aizen breathed heavily as his Reiatsu flowed out of him, trying to repel Kazuya away. He grabbed Aizen’s collar and curled his fingers into a chop hand position. The sharp nails on his gauntlet glinted menacingly as they aimed straight for Aizen’s chest — right where his heart should have been.

Wrapped in crimson flames, his hand was no less lethal than the edge of a Zanpakutō’s blade.

Clank! His fingers crashed into a solid object, and the flames started flickering as if they were under a fierce gale. The object drew in his flames and absorbed it as if it wasn’t one of the most destructive elements in the world.

He immediately yanked open Aizen’s Shihakushō. Stored in a hidden pocket was the object that devoured Nami’s flames as a snack — the Hōgyoku. Despite its dim, almost dying, its bottomless darkness captivated him.

A longing filled his chest. An urge more visceral than any he felt in his life.

{Partner, snap out of it! STOP DAYDREAMING!}

The urgent cries of Nami broke through the haze of temptation, bringing Kazuya back to reality. The distraction, while momentary, was more than enough for Aizen to capitalize.

A small black orb crackled in the space between him and Aizen, bursting with energy that twisted the very air.

“Hado #90, Kurohitsugi.”

Kazuya reached out to grab Aizen, but before he could make contact, a torrent of gravity pulled him towards the earth — into the abyss his Divine Tree had created. The black surface carved out of intricate closed around him, trapping him in the black box of torture.

This box was even larger and more terrifying than the one Aizen had used on Yoruichi.

Despite the swollen face, Aizen was smiling as the massive spears jutted out of the box. “The destruction of the fully chanted Kurohitsugi… Hōgyoku should survive.”

He barely brought out the half power of Kurohitsugi but it was more than enough to extinguish Captains. A Hollow who had no Reiatsu to her name would have no hope of survival.

“The most stubborn woman I’ve ever met.”

As he lamented the loss of a potential pawn, he sensed disturbances in space not far from Urahara's Shop.

“Useless as always,” Aizen muttered under his breath, forcing a weak smile to greet the approaching reinforcements.

At the same time, the black box faded. What’s left behind wasn’t a skewered corpse but a black armor wrapped in crimson flames.

Kazuya charged at Aizen to finish the job but he flashstepped to the Senkaimon, hiding behind his ‘comrades’. He didn’t give chase and simply hovered in the air as a hunched figure stepped out of the Senkaimon.

A bald elderly man with deep wrinkles and pronounced cheekbones. The massive cross-shaped scar above his eyes and the well-defined body hidden beneath his loose clothes were one of the few telling signs of his deep background.

General Genryūsai Shigekuni Yamamoto.

“Captain Sosuke, let the medics tend to your injuries,” Yamamoto said and sharply looked up at Kazuya. “Arrancar, you’ve caused much destruction to the living world. For what purpose?”

Kazuya stayed silent, staring at the two shadowy figures coming out of the Senkaimon. Following the old man were none other than Captain Retsu Unohana and her Vice-Captain Isane Kotetsu.

The Captain with a motherly demeanor stared at the tree for a long moment before busying herself in healing Aizen’s bleeding arms. “Stay still, Captain Sosuke… your injuries are severe. You only survived because of the dense Reishi of your body.”

Aizen nodded before smiling at Kazuya. “Captain Commander, please be careful. She has abilities even I couldn’t grasp.”

His warning was superficial. He wouldn’t mind if Yamamoto gets eradicated at Cazador’s hand.

“Thank god, you survived…” Isane whispered under her breath. “Captain, you should carry Captain Sosuke to the Soul Society with Minazuki. I’ll stay back with Captain Commander.”

Retsu nodded her head. “That’s the best course of action.”

Kazuya, meanwhile, couldn’t help but grit his teeth in frustration. The taste of victory was snatched from him, only because of his connection to the Hōgyoku. “Savor your triumph for today, Shinigami.”

{It’s fine, Partner. We got the Hōgyoku… Let’s go check up on Harribel.}

Yamamoto’s eyes widened at his voice, his red pupils filled with surprise.

Kazuya extended a hand toward the tree. The massive tree grew dimmer and dimmer, and disappeared out of existence, and the Reiatsu making it flowed back to him. Immediately, a portion of strength returned to him.

“That felt nice… Now, Old man, it was nice meeting you.”

He ripped open the Garganta with a flick of his hand and leaped inside. The lineup of Shinigami was extremely powerful. Kazuya couldn’t fight them all on his best day, much less in his current condition.

…

A/N: The Hōgyoku is saving Aizen even though they aren’t fused.