Time flowed like a river, indifferent to the struggles of mortals or the ambitions of gods. For me, Indra Uchiha, each day was measured not by the rising sun or passing seasons, but by the steady pulse of training, learning, and endurance. By the age of six and a half, nearly five years had passed since my first birthday—the day I had awakened my Six Eyes—and I had not wasted a single moment.
Every muscle in my body remembered the parable of struggle, every sinew and tendon a testament to years of relentless, methodical training. My body had been forged through hardship, my mind sharpened through Life Simulation, and my spirit tempered by the memories of loss and the unquenchable desire to reunite with Vidya.
The past years had not been idle. Among the milestones that shaped me were the births and growth of those around me. Izuna, my younger brother, had grown into a lively, curious child, his energy both a test of patience and a source of laughter. Madara, only a year younger than me, was sharp, stubborn, and endlessly mischievous—a constant reminder that even in a world of chaos, joy could flourish. My stepmother's guidance remained a warm anchor amidst the storm of training, and my father, Tajima, watched me with pride, envy, and the quiet knowledge that I was destined for a path unlike any other.
But the true turning point came on my sixth birthday.
It was then that the Life Simulation system activated in a form I had never experienced before.
Ding.
"You are going to be born in the Demon Slayer world. Noble household, son of a noble. Please choose two powers of your main body."
I hesitated for only a moment. The choices were simple for one who had seen countless universes: Six Eyes and Adaptable Body.(only adaptable body not healing factor)
Ding.
"Simulation start."
Demon Slayer Life Simulation Progression
Age 1: I was born into a noble household, my body already stronger than most babies. The adults around me whispered in awe, marveling at my vitality, my piercing gaze, and the subtle awareness that even now, at this tender age, I was not ordinary.
Age 2: I learned to walk and speak at an accelerated pace. The world unfolded before me like a map of endless possibilities, and I absorbed every motion, every gesture, every word with the precision granted by my Six Eyes.
Age 3: My younger sister was born. Even as a toddler, I sensed her importance—not only to my heart but to the tapestry of fate itself. I vowed silently that no harm would come to her if I could prevent it.
Age 4: I began learning my family's samurai swordsmanship. The techniques, balance, stances, and strikes became extensions of my body, almost instinctual. Training was rigorous, but the joy of motion, the harmony of body and blade, was intoxicating.
Age 5: Royal etiquette, swordsmanship, and discipline dominated my days. I memorized formal movements, gestures, and responses while continuing to refine my combat skills. My mind, body, and spirit were intertwined in preparation for the world's harsh realities.
Age 10: Mastery of my family's swordsmanship. I could anticipate attacks, strike with precision, and move as fluidly as water, as sharply as wind.
Age 12: Tragedy struck. My younger sister was killed by a demon. The world, innocent and cruel alike, left me with the first true taste of loss and vengeance.
Age 13: I tracked the demon relentlessly, learning fear, patience, and the raw intensity of the hunter's mind. Every step, every shadow, every whisper became a clue.
Age 14: I joined the Demon Slayer Corps. Training intensified, and I began to understand the brutal hierarchy and discipline required to survive.
Age 15: Confrontation with the demon that had slain my sister. Life hung by a thread, and in a moment of fatal desperation, I was saved by a master swordsman whose presence radiated authority, power, and skill beyond imagining Yoriichi Tsugikuni.
Age 16: I became the disciple of Yoriichi Tsugikuni, the creator of the Breathing Style. Sun Breathing became my guiding light, though at first I could not fully wield it.
Age 17: Learning Sun Breathing in earnest. Every movement, every breath, every pulse of energy was a lesson in discipline, resilience, and harmony.
Age 18–20: My body was pushed to the absolute limit. Hours of training blurred together, pain becoming metaphorical flames that forged my strength. My adaptability, heightened by my body and Six Eyes, allowed me to internalize techniques faster than anyone could imagine.
Age 21: I finally mastered Sun Breathing, incorporating my own understanding and experience into every strike. My abilities had reached the peak of human potential.
Age 21–25: My name became known throughout the Demon Slayer Corps. Countless demons fell beneath my blade, my unyielding personality earning both admiration and fear.
Age 26: Realization struck: Sun Breathing could not be used constantly without risking my body. I began developing my own style—Nature Breathing—melding my understanding of elements, movement, and energy flow.
Age 28: Creation of Nature Breathing. A style unique to me, harmonizing body, mind, and spiritual energy.
Age 30: Mastery of Nature Breathing. I became the first Nature Hashira.
Age 35: Sole living disciple of Yoriichi Tsugikuni. A living link to the origin of Breathing Techniques, a bridge between past and future.
Age 38: Confrontation with Kokushibo, Upper Rank One of the Twelve Kizuki. The battle was fierce; my Demon Slayer mark awakened fully, my body pushed beyond limits. Kokushibo, heavily wounded, retreated.
Age 40–50: My body aged and weakened due to Sun Breathing and repeated exertion. and Demon Slayer mark. I discovered the healing potential of Nature Breathing, gradually restoring my vitality.
Age 51–56: Retirement from active duty. Training disciples, rescuing them from demons, enduring 100 consecutive battles against countless enemies, and pushing my limits repeatedly. My body carried the scars and the strength of a lifetime.
Age 56: Final battle with Kokushibo. Find me for our Last Battle he Defeated I fell due to accumulated injuries, leaving behind a legacy carved in blood, steel, and unbreakable will.
Even in the simulation, each moment taught me something vital: endurance, precision, timing, and the value of protecting what matters most. My Six Eyes and Adaptable Body allowed me to absorb and internalize these lessons at speeds far beyond ordinary comprehension.
By the time I returned to reality in the warring shinobi world, the system marked me S-Class—the pinnacle of ability, resilience, and tactical knowledge. My physical form now rivaled the strength of adult Jonin-level shinobi. Fire, water, wind, lightning, earth, yin, and yang chakra attributes could no longer harm me. Even sharp weapons, blunt attacks, or explosions were trivial against my body. Sharingan remained dormant, Six Eyes active at ten percent of potential—but enough to give me a godlike perception of the battlefield.
I sat on the edge of the training platform, staring at my system panel.
System Panel:
Name: Indra Uchiha
Age: 6½
Chakra Attributes: Fire, Wind, Water, Lightning, Earth, Yin, Yang
Bloodlines: Uchiha 40%, Divine Six Eyes clan 30%, Senju 15%, Uzumaki 15%
Skills: Master Swordsman, Master Martial Artist, Master Sun Breathing, Master Nature Breathing
Sharingan: Dormant
Six Eyes: Awakened, 10% Power
Immunities: Fire, Wind, Water, Earth, Lightning, Yin, Yang, Sharp/Blunt Weapons, Explosions
Chakra Capacity: Elite Jonin Level
I let out a satisfied breath. Finally, the culmination of countless simulations, training sessions, and near-infinite mental calculations had yielded a body capable of surviving this chaotic era. My gaze turned outward to the battlefield—the warring state, the chaos of shinobi clans, and the faint but unmistakable trail of those who had wronged me.
It was time.
I flexed my fingers, feeling the flow of chakra through every cell. With the S-Rank boost, Life Simulation experiences, and Demon Slayer mastery internalized, I was ready for my first mission: finding Vidya, no matter where fate had cast her. Every step, every fight, every strategy I had learned would serve a singular purpose.
And so, with the wind brushing my face and my heart pounding with anticipation, I stepped forward. The river of years had carried me here—stronger, wiser, and unstoppable. Ahead lay the battlefield, the path to justice, and the hope of seeing Vidya again.
I smiled faintly to myself.
Finally… the hunt begins.
I will try post 2 chapter's daily i was using these story with CHATGPT I will writing my own story but only using for grammar mistake please support me with power stone's