The night air in my shack was cool, the faint hum of Konoha's distant bustle barely reaching this forgotten corner of the village. I sat on the floor, a stolen medical scroll spread out before me, its pages illuminated by a flickering candle. My hands moved through familiar seals, channeling chakra to heal a shallow cut I'd made on my arm—a test of precision, a reminder of control. But tonight, my mind wasn't on healing. It was on transformation, on sculpting my body into something more than human, something worthy of my ambitions: power, control, freedom.
In my past life, I'd been a gamer, lost in the worlds of Baldur's Gate and Warhammer 40,000. The latter had always fascinated me—not just for its grim battles, but for the Astartes, the Space Marines. They were engineered warriors, their bodies remade with two hearts, three lungs, and towering physiques that made them more than mortal. Stronger, faster, unyielding. In Jujutsu Kaisen, Ryomen Sukuna had done something similar, reshaping his form to become the perfect sorcerer, his physical prowess amplifying his cursed energy. Chakra, I'd learned, worked much the same way in this world. A stronger body meant stronger chakra reinforcement, a better vessel for techniques like Dismantle and Cleave. If I could modify my body, push it beyond human limits, I could elevate my power to heights no shinobi could match.
Hiruzen's visit last night had only sharpened my resolve. His talk of the Will of Fire was a distraction, a leash meant to bind me to Konoha. I wasn't here to serve a village—I was here to forge my own path. And that path demanded a body as unbreakable as my will
The medical scroll before me detailed advanced chakra-based surgery, techniques used by elite medical-nin to reconstruct tissue or replace organs. It was forbidden knowledge, meant for jounin or higher, but I'd slipped it from the village library weeks ago. My medical ninjutsu was already advanced for my age—closing wounds, numbing pain, enhancing stamina—but this was a new frontier. The Astartes inspired me: their dual hearts pumped blood faster, their extra lungs fueled endurance, their massive frames intimidated foes before a blow was struck. I didn't have gene-seed or Mechanicus tech-priests, but I had chakra and a mind honed by years of RPG strategy. I'd make it work.
My first goal was to enhance my cardiovascular system. Two hearts, like an Astartes, would increase blood flow, letting me sustain chakra reinforcement longer. The scroll described a technique to stimulate organ growth using chakra, a risky process that could kill an untrained shinobi. But I wasn't untrained. I started small, focusing chakra into my chest, targeting the muscle tissue around my heart. The sensation was strange, like a warm pulse spreading through my ribs. I visualized a second heart forming, a mirror of the first, its rhythm syncing with my pulse. Hours passed, sweat beading on my brow, but I felt a shift—a faint, secondary beat in my chest.
It wasn't a true second heart, not yet. The scroll warned that such changes required weeks of gradual reinforcement, building tissue layer by layer. But the proof of concept was there. My chakra reserves, already large for a twelve-year-old, felt steadier, my stamina bolstered. I pushed further, channeling chakra to my lungs, encouraging tissue expansion. The Astartes' three lungs let them fight in toxic environments and endure prolonged exertion. I couldn't add a lung outright, but I could strengthen my existing ones, increasing their capacity. By dawn, my breathing felt deeper, each inhale fueling my body with more oxygen than before.
Height was another matter. At twelve, I was already taller than most my age, my chakra-enhanced muscles giving me a lean, imposing frame. But I wanted more—Sukuna's towering presence, the Astartes' overwhelming stature. The scroll mentioned a technique to stimulate bone growth, used to repair fractures but adaptable for controlled elongation. I tested it on my forearm, channeling chakra to the bone marrow, encouraging slow, steady growth. Pain flared, sharp but manageable, as my arm lengthened by a fraction of an inch. It was a start, but scaling it to my entire body would take months, maybe years. I'd need to balance it with muscle reinforcement to avoid breaking myself apart.
The next day at the Academy, I tested my enhanced body in a sparring match against Kiba. His feral speed and Akamaru's coordination made him a tough opponent, but my bolstered stamina gave me an edge. I dodged his claw strikes with chakra-enhanced reflexes, my lungs drawing in air effortlessly, my heart—or hearts—pumping steadily. When he lunged, I wove a Mirror Mirage Technique, my illusory clones flickering with faint footsteps to confuse him. As he hesitated, I closed the distance, tapping his chest with a restrained Cleave, the contact-based technique stinging without cutting.
Kiba hit the ground, cursing, while Akamaru barked furiously. "What's with you, Archon?" he growled, rubbing his chest. "You're faster than last time!"
"Just training," I said, keeping my tone light. But inside, I was elated. The changes were small, but they worked. My chakra reinforcement felt stronger, my movements sharper. The Astartes' resilience, Sukuna's perfection—they were within reach.
After class, I caught Shikamaru watching me, his lazy gaze sharper than usual. "You're different," he muttered, almost to himself. "Not sure how, but… troublesome."
I shrugged, deflecting. "You should worry about your own training, Nara."
But his words stuck. The Ino-Shika-Cho trio had taught me the value of synergy, and I was applying it to my body—heart, lungs, bones, all working together to amplify my chakra. In Warhammer 40,000, the Astartes were forged through pain and precision, their bodies temples to war. I was doing the same, sculpting myself into a vessel for power.
That night, I pushed further, using medical ninjutsu to reinforce my muscles. I visualized the Astartes' dense fibers, capable of lifting vehicles or enduring lasgun blasts. My chakra flowed into my arms, legs, and core, strengthening tissue until I could crush a stone in my grip without strain. The pain was intense, but I dulled it with a numbing technique, my control unwavering. I tested my strength, lifting a log that should've taken two grown men to move. It felt light, my body humming with potential.
Genjutsu remained a focus, too. Inspired by the trio and my Baldur's Gate roots, I refined my shadow-based illusion, making it feel heavier, more oppressive, like a Space Marine's presence in a battlefield. I tested it on a stray dog, its eyes wide as it cowered under the false weight of my chakra. The Mirror Mirage Technique grew sharper, too, my clones now mimicking subtle gestures—a shift of weight, a glance—to sell the deception.
As I worked, I thought of Sukuna, his body a masterpiece of strength and menace. In Jujutsu Kaisen, his physical form amplified his cursed energy, letting him dominate any fight. Chakra was no different. Every modification—every heartbeat, every breath—made my Dismantle sharper, my Cleave deadlier. The Malevolent Shrine, my ultimate technique, still lay dormant, too draining to unleash, but with a stronger body, I'd wield it one day.
Hiruzen's scrutiny, Danzo's suspicions—they were obstacles, but they wouldn't stop me. In Warhammer 40,000, the Astartes were loyal to the Emperor, but I served no one. My body, my power, my path—they were mine to forge. Konoha was a stepping stone, a forge for my transformation. One day, I'd stand taller, stronger, a living monument to my will, and the world would know Archon as more than a shinobi—a force beyond reckoning.