Multiversal Manifestation System

For the next five months, Wang Zi dedicated himself to spreading Demon Slayer and training, only occasionally continuing Naruto. He released trailers and teasers on campus forums, ensuring they were cinematic enough to grab attention.

Meanwhile, Hua'er kept track of SP gains and monitored the cards he distributed, carefully curating the store's image as an elite, invite-only experience.

His gym sessions were rigorous. He spent hours in the gravity chamber, pushing his body to its limits, and sparring in the Illusion Sparring (I.S.) rooms. Initially, he tried recreating characters he admired, but the limitations of the I.S. system frustrated him. While it could summon illusions of characters like Garp from One Piece, it couldn't manifest their powers correctly.

"What's the point if it can't even use Haki?" Wang Zi muttered after one particularly disappointing spar.

"Or the Six Styles? This place needs better programming."

"Maybe the system can't create what you don't fully understand, Master. You can't expect the I.S. room to read your mind." Hua'er hovered beside him, smirking.

"Fair," Wang Zi admitted, though he was annoyed.

"Still, I hoped it'd at least get close. For now, I'll stick to using the gravity room. At least I know what I'm getting there."

Over time, Wang Zi noticed Demon Slayer spreading steadily. Every view, every reaction, every person who shared or talked about his work added to his SP reserves.

It had been five months since Wang Zi had embarked on his brutal training regime, and the transformation was nothing short of astounding.

The once massive frame of fat that had earned him the nickname "Fatty Zi" was long gone, replaced by a mountain of muscle that seemed carved from stone.

Standing at an imposing 2.2 meters tall, Wang Zi's sheer size was enough to make anyone stop and stare.

His wide shoulders, thick neck, and barrel-like chest gave him an aura of unmatched power, as though he could lift a small vehicle with ease.

His arms were tree trunks of raw strength, with veins running like rivers down their length, emphasizing the muscle packed beneath his skin. His hands calloused from relentless training, yet they held a surprising precision, a testament to his Ultra-Mind talent that ensured no movement was wasted.

Wang Zi's torso was a work of art. His abs rippled like a perfectly chiseled six-pack, each muscle group defined and bulging with the promise of immense strength.

His back, broad as a mountain, had lines of muscle that flowed seamlessly into his powerful legs, which were thick and sturdy enough to anchor his towering form like the roots of a great tree.

His once round face was now sharp and angular, framed by short red hair.

While his muscles were undoubtedly impressive, what set Wang Zi apart was how his physical transformation complemented his aura.

He no longer moved with the clumsiness of someone burdened by extra weight. Instead, he carried himself with the precision and fluidity of a seasoned martial artist, his every step exuding confidence and purpose.

He still liked using baggier outfits that concealed most of his form though. A loose, sleeveless tunic hung over his chest, paired with comfortable yet durable training pants, yet besides when he was training, all of this was covered by a very large robe.

Wang Zi's size alone would have made him intimidating, but the combination of his muscles, his confident posture, and the powerful aura he exuded made him seem almost inhuman.

Every movement he made was deliberate and precise, a sign of the discipline and effort he had poured into reshaping his body.

As Wang Zi stood before a large mirror in his room, he couldn't help but admire the results of his hard work.

His hand traced the ridges of his abs briefly, the once soft and rounded belly replaced by hardened muscle that felt like steel.

"Damn," he muttered to himself, a small smirk playing on his lips.

"If my old self could see me now, he'd be crying with envy."

He flexed his arm slightly, the bicep rising like a mountain, and chuckled.

"This world's supplements are a cheat. Coupled with mana, it's like having a personal sculptor carving me into perfection. If I had this back then…"

Wang Zi trailed off, shaking his head.

It wasn't just Wang Zi who noticed the transformation. On the rare occasions he walked through campus, heads turned wherever he went. Students whispered among themselves, awed by his size and physique.

Wang Zi, however, paid no attention to the stares or the whispers.

He had only one thing on his mind now.

As he got home, he immediately asked the system for his status.

Name: Wang Zi

Age: 19

Gender: Male

Class: Artist

Rank: SSS (Compatibility: 100%)

Level: 24

System Points (SP): 893,544,012

Talents

[Inhuman Reflexes]: Reaction speed increased by 50 times.

[Ultra-Mind]: Grants perfect memory, enhanced comprehension, and full control over the body.

[Uzumaki Blood]: Increases physical stats with emphasis on stamina.

[Elemental Affinity]: Natural control over the five basic elements.

Basic Stats (average human = 10):

Strength (STR): 183

Agility (AGI): 123

Stamina (STA): 201

Intelligence (INT): 520

Wisdom (WIS): 412

Luck (LCK): 20

Wang Zi leaned back in his chair, his fingers tapping rhythmically on the table as he contemplated his next steps.

His stats had improved significantly, his stockpile of SP was massive, and he felt ready to take the plunge into another world.

There wasn't much tying him to the Violet Tower at the moment, he wasn't attending the classes seriously anyway. The only thing left was informing Lulu about his upcoming "leave of absence."

With a shrug, he pulled up his holo-watch and initiated a call.

After a moment, Lulu's figure materialized before him. As usual, she was dressed in an outfit that seemed deliberately designed to be both casual and teasing, her blonde hair falling perfectly around her shoulders, and her green eyes gleaming mischievously.

"Wang Zi," Lulu began, her voice laced with amusement,

"What's this? I thought you'd fallen into some kind of hole-"

Her words stopped abruptly as she got a proper look at him. Her eyes widened in genuine shock as she took in his transformed physique.

Gone was the layer of fat she remembered, replaced by solid, sculpted muscle. His once soft features had sharpened, his red hair framing a jawline that could now cut glass. His broad shoulders filled the screen, and the baggy clothes he wore couldn't fully hide the sheer size and power he now exuded.

"What the hell..." Lulu muttered, leaning closer to the screen as if to confirm she wasn't imagining things.

"Who are you?"

Wang Zi smirked, his voice calm and measured.

"Who else would it be?"

Lulu recovered quickly, her teasing tone slipping back into place, though her wide-eyed expression lingered.

"You look like you've been sculpted out of iron. What happened to the cute little fatty I used to know? Did he eat this version of you?"

"I decided it was time for a change," Wang Zi said with a shrug, ignoring the 'cute' remark. "Figured it would be good to finally put all that training to use."

Lulu tilted her head, studying him with a mix of curiosity and approval.

"Well, I have to admit, you're looking... unrecognizable."

"Let's not get ahead of ourselves. Anyway, I didn't call to show off."

"Oh?" Lulu raised an eyebrow, her teasing smirk returning.

"Then to what do I owe the honor of this call?"

"I'm taking a break," Wang Zi said simply, leaning forward slightly.

"I need to handle some personal matters. Shouldn't take long, but I figured I'd let you know so you don't wonder why I'm not around."

Lulu's playful demeanor faltered slightly.

"Sorry, Wang Zi," she began, her tone softer than before.

"I know things haven't exactly been... ideal for you here at the Violet Tower. Honestly, I feel a little bad about it. You haven't been getting much out of this place, have you?"

Wang Zi raised an eyebrow, slightly surprised at her sincerity.

"Well, let's just say the classes haven't exactly been groundbreaking for me," he replied evenly.

"But I've been making it work."

Lulu sighed, brushing a hand through her blonde hair.

"I can see that. You've definitely been doing something right, considering how much you've changed in just a few months. I'm glad you've been improving yourself despite everything. It's impressive."

Wang Zi nodded, not entirely sure where this was going.

"Is there a point to this, Lulu? Or are you just buttering me up?"

Lulu rolled her eyes but smiled faintly.

"Actually, there is. I was talking with my artist friend a couple of days ago, and she mentioned that she'll be free in about three months. She said she'd be willing to visit the academy, so you'll finally get the chance to chat with her."

Wang Zi frowned slightly, his red brows drawing together in thought. Three months? That wasn't exactly ideal. He had every intention of staying in the Demon Slayer world as long as it took to accomplish his goals, and he couldn't afford to rush things. But... with the system's ability to pause time, it wasn't an insurmountable problem, even if it came at a cost of SP.

"That's... good news," Wang Zi said slowly, though his tone was tinged with reluctance.

Lulu tilted her head, her green eyes studying him curiously.

"You've always got something up your sleeve, don't you? Well, don't stress about it too much. Three months is plenty of time. Just let me know if anything changes."

Wang Zi nodded.

"I will. Thanks for letting me know, Lulu. And... thanks for keeping me in the loop, even if I've been a bit absent."

As the screen went dark, he sighed deeply, leaning back once more. With his SP reserves, he could afford a few detours if necessary.

"Well," Wang Zi muttered, "I guess it's time to get started."

As Wang Zi prepared for his journey to the Demon Slayer world, a nostalgic smile tugged at his lips. His decision had been made earlier in the day - he would meet Kanae Kocho, the gentle and kind elder sister of Shinobu, someone whose warmth and strength had left an indelible impression on him. The thought of her tragic fate made his resolve even firmer.

He would set the timeline just a few days before her death, perfect to witness how she actually died, before ultimately using Gedō - Rinne Tensei to revive her. He would offer her a choice to leave the current world - or go back to her eternal rest.

"I'll have to show her Shinobu and Kanao's fates... After all a little meddling for a teammate shouldn't hurt too much no?" Wang Zi shrugged as he thought.

He also knew the cost of speeding up time in the Demon Slayer world would be high, draining his SP, but it didn't matter, he had stocked up already expecting this.

Meeting Kanae was worth every point - IF she was anything like the anime had portrayed her to be.

Wang Zi walked to his wardrobe, pulling open the sleek, dark-paneled doors. Hanging neatly inside was a set of clothes that had become iconic in his original world, garments that symbolized both power and mystique - at least in a particular world.

The Akatsuki cloak was made of a deep black fabric that seemed to absorb the light around it, giving it an almost ominous aura. Red clouds, outlined in white, were scattered across the cloak, their vivid hue standing in stark contrast to the darkness of the material.

The collar was high, wrapping snugly around the neck, hiding half his face, while the long sleeves billowed slightly, allowing for free movement. The hem of the cloak fell just above his ankles, adding to the dramatic silhouette.

He paired the cloak with simple black shinobi sandals and loose, dark pants. To complete the look, he ruffled his freshly styled crimson hair into a hedgehog like style, a nod to Yahiko, the original owner of his appearance.

Wang Zi stood in front of the mirror, adjusting the collar and brushing off an invisible speck of dust from one of the red clouds. He tilted his head, appraising the ensemble. The cloak was very baggy, completely hiding his form, adding an air or mystery.

"Perfect," he muttered to himself, a smirk tugging at his lips.

"Besides the piercings, I look exactly like him." He couldn't help but chuckle to himself. Wang Zi didn't mind it though, although Yahiko wasn't extremely handsome, his face coupled with the Rinnegan had left a very deep impression.

He was glad it was Yahiko and not another appearance he had gotten in this life.

He turned to Hua'er, activating his Rinnegan and completing his look.

"What do you think?"

Hua'er crossed her arms, tapping her chin in thought.

"Well, Master, I have to say, it definitely screams 'I'm important, don't mess with me.'"

Wang Zi chuckled lightly.

Satisfied with his preparations, Wang Zi stepped away from the mirror, ready to embark on his long-awaited journey into the world of Demon Slayer. The Akatsuki cloak swished lightly as he moved.

It was time to meet Kanae Kocho and start a new chapter in both her story and his own.

Taking a deep breath, he steadied his nerves and gave the command.

"System, initiate reverse manifestation. Destination: the Demon Slayer world. Timeline: the location and time of Kanae Kocho's final battle with the Upper Rank Two demon, Doma, 5 hours before her death."

"Yes Host. Calculating trajectory..."

The system hummed, processing the complex request. A series of notifications appeared before his eyes as it calculated the trajectory, timeline, and environmental variables.

"Calculation Successful. Reverse Manifestation Initiating."

Before Wang Zi could fully process the message, the world around him blurred. His room dissolved into streaks of light and shadow, and in the blink of an eye, he was gone.

When Wang Zi's vision cleared, he found himself standing in a forest clearing bathed in the soft light of dusk. Towering trees with gnarled roots surrounded him, their leaves whispering in the gentle wind. The faint scent of pine and earth filled the air, mingling with an underlying metallic tang that hinted at the carnage yet to come.

He adjusted his cloak, the red clouds on the black fabric fluttering lightly as he turned in a slow circle, taking in his surroundings. The forest seemed empty, eerily quiet, with not a soul in sight.

Satisfied with the location, he let his Rinnegan activate. The purple ripple-patterned eyes flared to life, and with them, the world shifted into sharp focus.

The mana around him became visible, flowing like streams of liquid light through the trees and the earth. He took a deep breath, relishing the clarity his Rinnegan provided, no longer needing to suppress its power.

"The mana... is lacking to say the least. What a weak world..." Wang Zi sighed.

"Well, well," a familiar voice chimed in, breaking the stillness. "Someone's feeling dramatic."

Wang Zi glanced over his shoulder, his brow lifting slightly in surprise as Hua'er materialized beside him.

Her small, luminous form hovered just above his shoulder, her silver hair shimmering faintly in the waning light.

"You're here too?" he asked, his tone more curious than annoyed.

Hua'er smirked, placing her tiny hands on her hips.

"Of course, Master. The system made me your assistant, remember? Wherever you go, I go."

Wang Zi nodded, realizing it made sense. If the system had truly integrated her into its functions, then her presence in this world wasn't unexpected.

"Alright then," he said, turning his gaze back to the forest.

Hua'er tilted her head, observing his active Rinnegan.

"By the way, why do you always like to have those eyes of yours active? It's not like you need them all the time, do you? It's just... extra."

Wang Zi chuckled softly, the sound low and amused.

"Extra, huh?" He paused, considering how to explain it to her.

"Imagine this: you've had bad vision all your life. You put on a pair of glasses, and suddenly everything is clearer, sharper, you can see the world as it truly is. You'd want to keep them on all the time, right?"

Hua'er nodded slowly. "That makes sense."

"For me..." Wang Zi continued,

"It's the opposite. Not using the Rinnegan feels like putting on glasses that blur your vision, muffle your hearing, and dull your senses. It's not damaging, but it's uncomfortable as hell. With my Rinnegan active, I can see and sense everything as it should be. Without it... it feels like I'm half blind."

"Ooh!" Hua'er blinked, finally understanding. 

"It's not a vanity thing, despite what you might think." Wang Zi replied, glancing at her with a smirk. 

Hua'er grinned, but didn't comment.

Wang Zi then turned his attention back to the forest. His Rinnegan glowed faintly as he surveyed the area, searching for any signs of the fateful encounter to come.

"Now we wait huh." Wang Zi said, before beginning to float and hiding high in the sky, waiting for what was inevitable.