Multiverse Shenanigans: Raja's Journey

After receiving permission from Oyakata-sama, I wasted no time in seeking out my big brother Gyomei Himejima, the Stone Hashira, to begin my training. The look on his face when I asked him to train me was priceless—half surprise, half joy.

"You want me to train you?" Gyomei asked, his massive hands clasped in prayer.

"Of course!" I grinned, puffing out my chest in mock bravado. "I'm going to be the king of medicine and a warrior who slays the source of all curses—Muzan! Big bro, you're the strongest guy I know, so naturally, you have to train me!"

Gyomei's smile was like the dawn breaking over a mountain, warm and full of promise. "Very well, little brother. But know that my training is rigorous and will test your limits."

And so, at the ripe age of eight, I began my training. Gyomei didn't pull any punches—he had me lifting boulders, running up steep hills with weights strapped to my legs, and meditating for hours to strengthen my mind and senses. It was pure physical training for the first two years. But what astonished Gyomei was how quickly my body adapted to his extreme regimen. By the end of those two years, I could lift half the weight Gyomei could, which, considering he could lift literal boulders, was a massive achievement.

One day, while Gyomei and I were lifting weights that could crush a lesser human, he paused, sweat glistening on his massive brow. "Your body... it's adapting faster than any warrior I've ever seen. You could rival a Hashira's strength in just a few more years."

I couldn't help but smirk. "I am a genius after all. But big bro, this training—while incredible—needs more structure."

Gyomei raised an eyebrow as I began outlining a systematic training regimen for the future Demon Slayer recruits, breaking down different levels for men, women, and even kids. I suggested developing special diets for each age group to maximize their physical growth and strength. Gyomei nodded in approval, though he seemed to be wondering how an 8-year-old was thinking so deeply about nutrition.

With that, I approached Oyakata-sama with an even crazier idea. I handed him two pills—one labeled 5% and another 10%—and calmly explained that these were my own inventions: NZT pills that would temporarily unlock a higher percentage of the brain's capacity. The 5% pill was for the Demon Slayer recruits, while the 10% pill was for the Hashira and their descendants.

Oyakata-sama stared at me, blinking in disbelief. "You want me to test these... myself?"

I nodded, handing him the 10% pill. "It will enhance your cognitive abilities, making the planning and execution of strategies far more efficient. Trust me. And as for my big bro—" I grinned, mischievously, "I gave him a 15% pill, but I told him it's only 10%. Let's see what happens."

Oyakata-sama's eyes widened. "You—!"

But before he could finish, he tested the pill. His pupils dilated as the effects began to settle in, and he immediately started scribbling plans and executing them faster than ever. Schools, hospitals, and financial institutions were established within months, thanks to his newfound cognitive prowess. And all the while, Gyomei was growing stronger and more perceptive, his strength nearly incomprehensible after the pill. He could now sense even the faintest presence of demons in a hundred-mile radius.

I gave recruits a tonic to drink during their training, which would increase their IQ to 5% brain capacity over two years, allowing them to be fully ready by the time they started their swordsmanship and breathing techniques. I also developed a five-year training plan: two years of body training and three years for swordsmanship and breathing. For the sake of efficiency, I created several departments to handle the increasing scale of operations: Charaka Medicine Department, Financial Department, Training Department, and an Education Department to oversee the training of future recruits.

The schools, named after Goddess Saraswati (known as Benzaiten in Japan), were designed to educate orphaned children, providing them with food, shelter, and training if they showed potential as future Demon Slayers. These schools were scattered across every town, acting as hubs to identify potential recruits. To ensure these schools ran efficiently, I created a team of shadow agents, elite assassins who would watch over the schools in secret, punishing anyone who mistreated the children or broke the rules.

To fund all of this, I gave Oyakata-sama a casual gift: 100 tons of gold.

He nearly fainted when I presented it. "W-Where did you get this?!"

I shrugged. "I've been collecting treasures since I could walk. It's nothing."

"Nothing?!" He rubbed his temples, realizing just how deep my mysterious background went. But with his enhanced brain power, Oyakata-sama quickly put the gold to good use, building hospitals, pubs, and information networks, which made the Demon Slayer Corps even more efficient.

Two years of training passed, and it was time to take the next step. I approached Oyakata-sama again and asked to begin learning sword techniques and breathing methods.

Oyakata-sama smiled knowingly. "The breathing techniques originated from a single source—the Sun Breathing. Over time, the various Hashira developed their own unique styles based on the elements: Water, Fire, Wind, Thunder, and Earth. Which one would you like to learn?"

I grinned mischievously. "All of them."

He blinked. "All?"

"I'm at 25% brain capacity. I can handle it," I replied, smirking.

He stared at me, speechless for a moment. Then, with a sigh, he handed me a sealed letter. "This will explain your... unusual request to the Hashira. Present this, and they'll train you."

I eagerly took the letter, hoping to sneak a peek at its contents, but Oyakata-sama hid it away, much to my frustration. Still, the journey to mastering all the breathing techniques had officially begun.

My first stop was none other than the Water Hashira, Sakonji Urokodaki. When I arrived at his home, he looked at me like I was a lost child. "What's a kid like you doing here?"

I handed him the letter. His expression changed from serious to surprised to utterly shocked. After reading the letter, he addressed me as "young master" and led me inside with newfound respect.

Sakonji tested my strength and was impressed enough to train me for six months. During that time, I not only mastered the Water Breathing technique but also made some improvements to its efficiency. Sakonji was grateful and gave me another sealed letter for the next Hashira.

My journey continued with the Former Thunder Hashira, Jigoro Kuwajima, where I trained in Thunder Breathing. Next, I learned the Flame Breathing from Shinjuro Rengoku and even trained alongside his children, Kyojuro and Senjuro. I gave them 15% pills, unlocking their full potential as warriors. They were grateful beyond words.

The real challenge came when I arrived at Tengen Uzui's household. Descended from a family of shinobi, their training was brutal—enough to kill ordinary children. So, I did what any rational person would do—I beat the crap out of all the family heads. When they realized I wasn't here to play around, they listened.

"We can achieve the same results with systematic training," I lectured them. "There's no need to kill kids!"

Tengen was in awe of how I wiped the floor with the elders. We became fast friends, and I gave him a 15% pill, making him faster and deadlier than ever. His breathing style, Sound Breathing, evolved as I trained him further, and he began moving at speeds that broke the sound barrier. I combined elements from his Sound Breathing to create my own style—Wind Breathing.

Finally, my last stop was with Gyomei, who taught me Earth Breathing. His senses were terrifying, even more so now that he had manifested his Demon Slayer Mark. However, this mark came with a price—it was known to shorten a Slayer's life. To counter this, I developed a Vitality Medicine to prevent premature death from the mark, ensuring that Gyomei could continue his work for years to come.

After five long years of training, I had mastered all five elemental breathing techniques—Water, Fire, Wind, Thunder, and Earth. With these foundations, I created my own breathing style: Tempest Breathing, inspired by Rudra, the stormy and furious form of Lord Shiva.

Here's an updated version of the Five Tempest Breathing Forms, These forms creatively combine the elements from other breathing styles like fire, water, wind, thunder, earth, sound.

Five Tempest Breathing Forms

First Form: Typhoon Slash

A rapid spinning attack that combines wind and sound, creating a vortex that slashes everything in its path. The move generates a deafening roar as it strikes, disorienting foes and overwhelming them with relentless pressure.

Second Form: Firestorm Rage

A destructive burst of fire and wind, igniting everything within the radius with the force of a hurricane. The swirling flames are fed by the wind, turning the battlefield into a fiery tempest that incinerates enemies in its path.

Third Form: Thunderclap Tempest

A fusion of thunder and wind, striking with lightning-fast precision and explosive power. The attack hits multiple targets in quick succession, each blow accompanied by a flash of lightning and the roar of thunder.

Fourth Form: Raging Flood

Combining water and wind to unleash a powerful torrent that drowns and sweeps away enemies. The swirling waters gain momentum from the wind, creating an unstoppable flood that washes over the battlefield and engulfs foes.

Fifth Form: Quaking Storm

A powerful ground-shattering move that combines earth and wind. The user slams their sword into the ground, causing tremors and sending shockwaves of wind that shatter the earth beneath, disorienting enemies and destroying the terrain.