Batman in Konoha

Few in Konoha were surprised that the head of the Uchiha clan was known for his passion for science. Fugaku had never been just a warrior. There was always a sharp intellect behind his gaze, and even during his Academy years, scrolls with jutsu techniques coexisted peacefully in his hands with books on poison crafting and trap setting. He certainly had a talent for combat. But he never neglected preparation, analysis, and research.

After the end of the Third Great War, Konoha's high-ranking officials noticed that Fugaku's passion for science had intensified dramatically. He even built his own laboratory directly beneath his home. And again, no one was surprised—war changes people.

Even Mikoto, who had known him her entire life, wasn't surprised. As a wife who respected personal boundaries, she accepted her husband's decision without question. She never entered the laboratory.

Sometimes, Fugaku would call on Shisui and Itachi to help—hold a test tube, log some data, run a basic analysis or trial.

Itachi—serious, focused, attentive—always followed instructions precisely.

Shisui—curious, a mischievous spark in his eyes—sometimes asked too many questions, but never crossed the boundaries Fugaku set. They had both seen the laboratory, both knew their father was working on something important for the clan or for Konoha as a whole. But neither suspected that beneath their feet, deeper than they could imagine, another level was hidden.

A hidden lab.

Fugaku stood by the far wall and, listening closely to make sure the house was truly empty, pulled on a barely visible metal plate embedded in the concrete. A mechanism engaged—there was a click, then a soft hum, and a section of the wall slid aside, revealing a narrow passage and a metal staircase leading downward. The concealed hatch closed behind him, cutting off the light from above and leaving only the dim glow of the lower level.

The space looked nearly identical to the upper lab—glass cabinets, shelves of tools, glimmering reagents. But the atmosphere here was completely different. This was where he reconstructed formulas and inventions from a past life.

On the long table by the far wall lay a project he had spent over a year on. Beneath a flask secured with steel clamps, a thick, almost fluorescent bright green liquid flowed slowly through curved tubes. A device hummed softly as it heated the mixture, pressure building until the substance began to drip, drop by drop, into a vial set under the intake valve.

A muscle steroid. In his former world, it was called Venom.

There, it had been a source of incredible power… and inevitable ruin.

After defeating Bane—in a battle where the enemy had nearly shattered his spine for good—Thomas hadn't left anything to chance. He investigated the origin of the substance Bane used. The truth was horrifying and all too familiar: government experiments, underground labs, test subjects pulled from prisons. The goal was simple and insane—create the perfect soldier. A single dose could turn even the most frail and exhausted man into a machine of destruction. But the price…

The price was almost immediate degradation. Mental faculties plummeted like a stone in a well, the body burned itself out from within. Early versions of Venom killed within weeks. But over time, the formula was refined—strength increased, side effects lessened. It was this improved version that Bane had stolen. It granted monstrous power without loss of intellect, but still destroyed the body slowly, inevitably. Every injection cut a year off one's life.

Thomas wrestled with the formula for years. Ten years of research, trials, errors, improvements. But the solution, strangely enough, hadn't come from chemistry. It came from this new reality.

This world had something Gotham never did—chakra.

Chakra—mystical energy flowing through every shinobi's body—strengthened cells, accelerated regeneration, and, as it turned out, neutralized the destructive effects of Venom. Fugaku had confirmed this personally—on test subjects bought off the black market, criminals who were never meant to return to society. He administered the drug, monitored them, measured, documented every effect.

And unlike Bane… their bodies didn't die.

They grew stronger. Faster. Their skin thickened, muscles expanded, but their minds remained intact. Their emotions, too. Chakra acted as a buffer, a stabilizer. Combined with Venom, it created something new. Something perfected.

Fugaku stripped off his outer clothing. A dark long-sleeved shirt dropped to the floor, followed by his boots. He remained in loose training pants. The lab was cool, but Fugaku didn't shiver. He knew what was about to happen to his body in the next few minutes—and he was ready.

He walked over to the table where a syringe lay waiting, already prepared and sterilized. Beside it sat a vial filled with bright green liquid. Venom. A serum that altered a man on the cellular level.

He sat on a high stool, positioned himself comfortably, and slowly—like a surgeon—drew several milliliters of the substance into the syringe. His movements were calm, as if he were preparing a routine vaccine. He found a vein on his forearm and, without hesitation, pushed the needle under his skin. A sharp prick—then the thick liquid began to enter his bloodstream.

The reaction was nearly instant.

Fugaku didn't scream, though pain exploded through his body like fire. His muscles spasmed and seized, the stool toppled, and he crashed to the cold floor. His body convulsed—his teeth clenched so hard it was a wonder they didn't shatter, thick saliva dripping from his chin. His chest expanded like bellows of a forge, as if a volcano was igniting inside him.

Through the pulsing agony, he felt his skin flush, every muscle swelling from within, tearing and then reforging itself—stronger, larger. Veins bulged like living snakes along his arms and neck, surfaced across his forehead and down his ribs. His bones—each one—cracked like brittle twigs. His height began to shift, joints popping loudly, spine stretching. Pain? Yes. But not uncontrollable. He endured it.

The minutes dragged like an eternity before it was finally over. The tremors stopped. His heartbeat, pounding violently in his temples, began to slow. He lay there on the floor, breathing heavily, soaked in sweat and power. The air was thick, buzzing in his ears, but every cell in his body… was alive. Awakened. Reinforced. Renewed.

Slowly, with the grace of a predator, Fugaku rose. His legs no longer felt familiar—they were thicker, heavier, like columns built to bear the weight of a titan. He walked toward the tall mirror mounted to the wall and looked at himself.

A stranger stared back.

Massive shoulders. A chest like an elite fighter's. Perfectly sculpted muscles, bulging veins. His face had sharpened: cheekbones more pronounced, jaw wider. He looked like a statue brought to life—a Greek hero carved from marble.

He stood to his full height and blinked in mild surprise—the mirror reflected a man at least twenty centimeters taller than the one he was used to. From his usual one-eighty, he'd crossed the two-meter mark. Fugaku was now one of the tallest people in the village—and possibly the most intimidating.

"This is what a shinobi should look like—commanding respect without a word," he murmured with satisfaction.

Itachi would understand.

Shisui would joke.

And Mikoto… she would likely remain silent, as always, quietly accepting whatever change came over him.

A sudden change in physique could be explained by many things—in a world full of jutsu and anomalies, such transformations rarely caused panic. Muscles? Who knew how many secret training sessions the head of the Uchiha clan undertook. Height? Shinobi had techniques to instantly lengthen hair, increase breast size, even slow aging. Some clans could change their appearance entirely.

But he had an even stronger argument—hiden jutsu. A personal, secret art. Legal, recognized, but not subject to disclosure. If a shinobi said their technique was hiden, pressing for details was considered rude. One word was enough to end any conversation. And he would use it, if necessary.

Fugaku touched his neck, checking his pulse. Everything within normal limits. He could feel the strength surging through his veins, his muscles harder than wood, his skin tougher than armor.

This was a super-soldier serum. A weapon capable of shifting the balance of power in the shinobi world. And he had no intention of sharing it with anyone.

Venom required regularity. One injection per week—and the body remained in optimal condition. Without maintenance doses, the muscles would gradually shrink, the body weaken. But with discipline, the results were undeniable.

Now, he had a body that could withstand the most extreme stress. He already felt faster—his leg muscles coiled like compressed springs. He could likely leap over the rooftop of a neighboring house in a single bound. As for strength… he could already picture his punch shattering an opponent's shield and the stone wall behind it.

It was time to rethink his combat arsenal. Techniques once deemed too dangerous for his own body were now safe to use.

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Author notes:

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