Slime Soul (Tensura x Bleach Crossover) (Patreon)

Chapter 8: Unknown Variable

Las Noches — Neliel´s POV

Neliel quickly made her way out of the location where Caius and the Ninth Espada had been battling, with the former cradled in her arms in his slime form, unconscious and undergoing evolution. She knew it was better to hide for the time it would take Caius to finish evolving, rather than remain in the same place and risk another Espada coming to investigate who had killed Aaroniero.

She especially hoped to avoid running into Nnoitra. While he had been the one responsible for weakening her and ripping off Pesche and Dondochakka’s masks, Neliel wasn’t one to hold a grudge and mostly felt pity for the man. There was also the fact that she didn’t know how strong he had become while she was indisposed, and she wouldn’t risk Caius’s life over something like that.

Caius had placed his trust in her and she promised herself that she wouldn’t let him down no matter what came her way.

Looking at her recent, yet no less precious, friend, Neliel couldn’t help but worry. The usually vibrant blue slime now looked as if all the color had drained from him, making him appear lifeless. If it weren’t for the small but steady presence she constantly felt from him, especially noticeable in her arms, Neliel might have thought he was dead.

Using her Pesquisa, she could sense the others already facing their respective opponents, and she relaxed slightly when she felt they weren’t fighting anyone particularly strong.

With her mind more at ease, she continued through Las Noches. Taking the opportunity, she searched for clothes. While she didn’t really mind if Caius or her Fracción saw her like this, trusting them with her life, she didn’t want to expose herself to anyone else. Especially since, beneath the tattered rags she wore, she had no underwear or bra. Not that they would have survived her transformation back into her original form anyway.

Fortunately, there were several rooms scattered throughout Las Noches that contained clothing, and she soon found one. Setting Caius down gently, she discarded her torn green garments and was soon dressed in an almost identical replica of the outfit she used to wear as an Espada.

Sheathing her Zanpakutō at her side, she reached for Caius once more, then paused.

He had begun to glow, a radiant shimmer blooming across his surface in all the colors of the rainbow.

Neliel blinked, frozen in place.

“Beautiful,” she whispered, transfixed as she realized his evolution was about to begin.

Unfortunately, that was when she sensed a powerful spiritual presence heading directly toward her, one stronger than Aaroniero's, which made her frown.

“I guess fighting was inevitable,” she muttered, quickly picking Caius back up and securing him to her back using a makeshift sling fashioned from spare clothing. Then, remembering the tattered rags Caius had been wearing earlier, she grabbed some fresh clothes in his size and stashed them in the bundle as well.

“Don’t worry, Caius. I’ll protect you,” she said firmly, her eyes steeled with determination.

With that, she left the enclosed space and made her way to a more open area, somewhere she’d have room to fight properly if it came to that.

She didn’t have to wait long.

Moments after she arrived, her opponent appeared. A tall, muscular, dark-skinned Arrancar with large lips and an imposing aura. The moment she felt his spiritual pressure, Neliel guessed he must be another Espada. Probably the Seventh or Eighth.

“To think a Hollow would turn against Aizen-sama and betray their own,” the man said, his expression mostly blank, though Neliel could see the flicker of anger in his dark eyes.

“I didn’t betray my own,” Neliel replied calmly, thinking of Caius, Pesche, and Dondochakka. They were the only ones that mattered now, the ones who had stayed by her side when she was at her weakest.

“And it’s been a long time since I served Aizen,” she added, her voice sharper. “Before he discarded me like trash. Believe it or not, Aizen doesn’t care about us.”

“Insolence!” the man barked, shaking his head before drawing his Zanpakutō and leveling it at her. “Now hand over that creature on your back. Aizen-sama wishes to meet it.”

Neliel’s frown deepened, a spark of anger flashing in her eyes. Slowly, she drew her own Zanpakutō and held it steady in front of her.

“He’s not a creature. He has a name. His name is Caius Aurelius,” she said, her voice unwavering. “He is my precious friend. And I would rather die than hand him over.”

“Then further talk is pointless.”

And just like that, her battle began.

=====

Great Sage’s POV

Great Sage was changing.

Slowly but surely, she was evolving from nothing more than a skill designed to assist her user, now known as Caius Aurelius, into something more.

And it was all thanks to her Master.

He had never treated her as a mere ability born from his soul, but as a true partner, someone he relied on and trusted completely. That was why Great Sage always gave her all, using every bit of her computational power to find ways to make her Master stronger, all in the name of protecting him at any cost.

Drawing from the fragmented memories of his previous life, Great Sage meticulously reviewed every piece of knowledge that might prove useful. From following the path taken by her Master’s other self, Rimuru, and memorizing every skill and ability he had acquired, to scouring memories of various “anime” her Master had once watched, nothing escaped her analysis.

To serve her Master to the fullest, she had committed all of his memories to perfect recall and was constantly running simulations, experimenting with ways to upgrade his skills and abilities.

Among all potential sources of power, one stood out above the rest, the Espada.

And, fortunately for them, they were currently at war with the Soul Society. It was the perfect opportunity for her Master to grow stronger. What’s more, Great Sage had discovered that the Espada resonated deeply with the Sin Series skills, almost as if they were derived from them.

If they could absorb or analyze more Espada, whether through devouring them or forming a Soul Corridor, Great Sage believed they might be able to recreate another Sin Series Skill.

But one problem remained, and it was the one that frustrated her the most: computational limitations.

As a Unique Skill, there was only so much she could do. Her capacity, while vast, had boundaries.

Thankfully, that problem was on the verge of being solved. Once her Master completed the Harvest Festival and became a Demon Lord, everything would change. Great Sage, soon to be known as Raphael, Lord of Wisdom, would continue gathering data relentlessly. And when she finally evolved into a Manas, it would be with the best possible foundation and resources available.

It didn’t matter who stood in their way.

Aizen. Zero Division. The Soul King. Yhwach.

They would all fall before her Master, if she had any say in it.

“I will protect Master from everything.”

With that final, unwavering thought, Great Sage poured herself into his evolution, refining every element of his transformation, while keeping a sliver of awareness trained on the world outside, in case she needed to intervene.

=====

Back With Neliel vs Zommari

Now that Neliel was back at full power, it didn’t take long for her to dispatch the much weaker Zommari Rureaux, whose name she had learned during their brief battle.

On the way to Las Noches, Caius had explained which Espada he considered troublesome. While Neliel and the others had been curious about how he knew such information, she was grateful for it.

Zommari’s abilities were dangerous, true, particularly his power to control any limb his attack touched, but despite boasting the fastest Sonído among the Espada, he was much slower than Neliel. She easily avoided his attempts to land a hit, denying him the chance to release his Zanpakutō, and swiftly ended the battle with a fatal blow.

Though Neliel disliked unnecessary violence, she wasn’t above finishing off an opponent, not when they posed a threat to those she cared about. With Caius still deep in his evolution, she had no other choice but to harden her heart.

Then, almost as if on cue, just moments after her battle ended, Neliel felt Caius’s energy settle. She quickly found a safe spot and gently laid him on the ground before her.

“Wow… his slime form got bigger,” she muttered, noticing he had nearly doubled in size, now around 80 centimeters in length.

A moment later, his body began to glow gold. She blinked and stepped back as his form slowly rose into the air, beginning to shift.

His transformation unfolded before her eyes as he gradually took on a human form.

Neliel noted absently that he was now taller than her by a bit, when before, they had been the same height.

‘Looks like his human form had a growth spurt too.’

When the light finally faded, revealing his new appearance, her cheeks warmed.

Caius had already been handsome before… but now his looks were flawless, as if every imperfection had been carved away, leaving something that felt almost divine to behold.

‘He’s… beautiful.’ The thought slipped quietly through her mind before she shook herself free of it. Her attention snapped back to reality as his eyes opened, now a deep crimson instead of the golden hue she’d grown used to.

Those eyes locked onto her, and her heart skipped a beat.

He was dressed in a simple white robe with a hood that draped over most of his head and extended down to his knees.

“H-How do you feel, Caius?” she asked, trying to sound casual, though she cursed herself internally for the stutter. But something felt… off.

His eyes weren’t looking at her with the same warmth she’d come to rely on, even crave.

‘A side effect of the evolution, maybe?’ she thought, searching for a logical explanation.

At her question, Caius blinked once, then looked past her, toward the dying form of the Octava Espada. Without a word, he stepped forward.

Neliel frowned slightly at being ignored.

Caius raised a hand and, for the first time, spoke.

“Beelzebuth.”

With that single, ominous word, what looked like a miniature black hole manifested in the air, and in an instant, Zommari’s body was devoured.

Neliel’s frown deepened. Watching him consume a defeated enemy made her uneasy. She opened her mouth to question whether that was really necessary, but stopped as those crimson eyes returned to her.

“Notice. Follow me. Your subordinates, Dondochakka and Pesche, as well as the Shinigami Renji and the Quincy Uryu, are in danger,” “Caius” said.

Only… the voice wasn’t quite right and his body looked more feminine for some reason.

It was Caius’s voice, and yet, not.

It had a strange, feminine undertone matching his figure that made Neliel narrow her eyes, her mind finally piecing things together.

“…Are you really Caius?” she asked cautiously, her hand drifting toward her Zanpakutō despite his warning.

The figure tilted its head slightly, making no threatening movement.

“Acknowledged. Time is short. If you will not follow, we will proceed alone.”

Neliel studied him, it, for a moment. Despite the foreignness of his voice and presence, there was no malice in those eyes. Finally, she relaxed and nodded slowly.

“Fine. But you’ve got a lot of explaining to do later.”

“Acknowledged.”

As the word left his lips, a blue magic circle spread beneath their feet. Neliel blinked in surprise as her vision was consumed by white light.

When she could see again, her eyes widened.

They were now standing just a short distance from Renji and Uryu, locked in battle with someone very familiar to her.

Szayelaporro Granz.

To the side, the unconscious bodies of Pesche and Dondochakka lay crumpled on the ground, sparking concern in Neliel’s chest.

But before she could speak, the being in front of her, her friend, or whatever now lived inside him, was already moving vanishing from her side in a sudden blur of motion.

Szayelaporro had only just turned his head, surprised by the new arrivals and momentarily ignoring Renji and Uryu, when a slender hand gripped his face and slammed him into the ground with such force that it cracked the blue stone beneath them, forming a crater.

“What—?!” he gasped, blood trickling from his mouth.

Renji and Uryu both jumped back, blinking in shock at the sudden, devastating appearance.

“Caius” then raised his free hand, where his sword materialized, wreathed in dark orange flame, and brought it down without hesitation, piercing the Séptima Espada’s heart.

“Ghaaa!” Szayelaporro gasped, eyes wide with pain and disbelief. His hands moved shakily toward the blade, trying in vain to pull it out. “W-Who a-are— cough —you?”

“Shit, that kid is brutal,” Renji muttered to Uryu, who slowly nodded.

Instead of answering, Caius pulled his blade free, drawing another cry of agony from the Espada. He then raised his palm once more.

“Beelzebuth.”

A void opened in the air and instantly swallowed Szayelaporro whole. In moments, nothing remained, not even his spiritual pressure.

Seemingly finished, Caius vanished again, reappearing beside Neliel and startling her with the sudden return.

No words were spoken at first. Then, a soft voice echoed directly into her mind, the same one she’d heard just moments ago.

“Notice. This body will fall unconscious in a few moments. Please continue to protect it a little longer.”

Neliel’s eyes widened, but she caught him—them—just in time as Caius collapsed, his body already shifting back into slime form mid-fall.

She cradled him gently in her arms, her heart still pounding from the suddenness of it all.

“You have a lot of explaining to do when you wake up, mister,” she whispered, making sure no one could hear her, eyes lingering on her precious friend’s sleeping form, so peaceful, as if nothing were wrong with the world.

=====

Las Noches — Monitoring Room

In a dimly lit room filled with the glow of dozens of large monitors, a brown-haired man sat alone. His slicked-back hair and handsome face were framed by the soft blue light of the screens. He smiled to himself, eyes locked on one monitor in particular.

It displayed the aftermath of a brutal scene, the room where the Séptima Espada had met his end at the hands of an unknown variable.

“Fascinating…” he murmured, his smile widening slightly. With a few keystrokes, he brought up another recording: a slime, of all things, transforming into a human and swiftly, mercilessly cutting down the Noveno Espada this time.

“Just what are you?” he whispered to himself, eyes narrowing in curiosity. Another tap of the keyboard brought up footage of the slime undergoing a strange, radiant evolution after his battle with the 9th Espada.

“I need more data. So far, he’s only faced weak opponents,” he said, his gaze now shifting to another monitor, this one displaying the former Tres Espada, Neliel Tu Odelschwanck gently cradling the slime to her body.

A thoughtful expression crossed his face… and then an idea began to form.

“Hmhmhm. I believe a reunion is in order. That should keep her occupied… while Ulquiorra tests him.”

A sinister yet amused smirk played across his lips as he leaned back, completely at ease, content to watch the pieces fall into place.

“I hope there’s more to you. You’re proving to be just as entertaining as Ichigo.”