The success of the "Preliminary-tier Natural Energy Puppet Core" was the "Installation Key" to a new world. I didn't waste a second; I immediately applied this breakthrough to the most critical piece of hardware I owned: the Body Tempering Furnace. It was the device that had rescued me from a "Total System Failure" at birth, and it was time for its biggest update yet. As an engineer, I understood that software is only as powerful as the hardware it runs on. I had the "Operating System" of a master-level soul and the "Energy Source" of a God-Tree shard, but my physical body was still a legacy build, a scrawny, nine-year-old frame that acted as a massive bottleneck for my potential.
The upgrade to the Body Tempering Furnace Mk-III was an engineering nightmare. Integrating a Natural Energy core wasn't like swapping a battery; I had to rebuild the entire energy conduction network of the furnace from the ground up. The "Life Force 2.0" energy emitted by the new core was far denser and more volatile than the standard chakra streams I had used previously. If the internal conduits weren't perfectly aligned, the resonance would create high-voltage "hotspots" that would cook my organs rather than repair them.
After several sleepless nights of focused debugging, I used high-purity Iwa-grade alloys to reinforce the primary energy bus. I etched new "Distribution Arrays" based on the medical meridians I'd studied under Granny Chiyo, ensuring the energy would be distributed with microscopic precision across my entire biological system. I needed the energy to be "Broadcast" at a frequency that matched my own cellular vibration. Finally, I seated the Natural Energy core into the furnace's drive-bay.
Buzz--
A deep, powerful hum resonated through the workshop, a frequency so low I felt it in my marrow before I heard it. On the furnace walls, the jagged blue chakra paths were replaced by a warm, milky-white glow, flickering with a rhythmic, steady pulse. The air in the room became charged, vibrant, and incredibly clean, as if the machine was scrubbing the very atmosphere of the desert grit.
I stripped down and stepped inside the cold metal cylinder. The hatch hissed shut, sealing me in a total sensory deprivation environment.
"Boot sequence: Initialized," I whispered. "Execute: Full-System Reinforcement."
The experience that followed was a total sensory override. This wasn't the gentle "repair-cycle" of standard chakra that felt like a warm bath. This was a warm, irresistible tide of primal life-force, the energy of the Divine Tree penetrating every layer of my being. It didn't just "fix" things; it rewrote them. This power wasn't satisfied with just patching damaged cells; it was stimulating the hidden potential in my DNA, forcing a "Hard-Reboot" of my entire physiology.
I could feel my cells waking up. My bone density increased as the minerals in the furnace's "Alchemical Bath" were drawn into my marrow by the magnetic flux. My muscle fibers reorganized into a more optimized, high-torque configuration, becoming leaner but significantly more powerful. My metabolism stabilized at a peak efficiency level I hadn't thought possible. This wasn't just "enhancement", it was a re-format of my biological OS.
The "Legacy Bugs" from my premature birth, the faint weaknesses in my lungs and the slight tremor in my left hand that even the Gen-2 furnace couldn't touch were finally deleted. I felt coordinated, transparent, and terrifyingly powerful. The "Dampness" in my lungs that had haunted me for nine years vanished, replaced by a deep, effortless capacity for breath.
As my physical body evolved, my spiritual energy, the thirty-year-old soul from another world integrated even tighter with the new hardware. The synchronization triggered a massive output event. In the darkness of the furnace, my internal "HUD" showed my chakra levels redlining.
Boom!
A volume of chakra far mightier than I'd ever felt surged through my system like a bursting dam. It wasn't just "volume"; it was "purity." The bottleneck that had stalled me at the Chunin level was obliterated as my widened meridians accommodated the new, high-pressure flow. I felt the surge level out and stabilize at a solid Jonin-level reserve. I was nine years old, and I finally had the "Engine" of a master.
When the session ended and I stepped out of the furnace, the world looked different. My vision was "High-Resolution," catching the microscopic movement of dust motes in the air. My hearing was "High-Frame-Rate," tracking the distant footsteps of patrols outside the workshop. I clenched my fist, and the air cracked with a minor sonic boom, not from a jutsu, but from raw physical torque.
"System Update: Body Tempering Furnace Mk-III... Successful," I whispered, looking at my steady, powerful hands.
With the energy problem solved and my hardware optimized, I finally turned my full attention to the "Mirage" project. With Jonin-level chakra and the enhanced processing power of my evolved brain, I could finally handle the complex "Vector Calculus" required for a true Maglev platform.
I spread the huge design scroll across my workbench, my mind moving with a speed and clarity I hadn't possessed even in my previous life as Logan.
Using the Natural Energy core as the "Server," I mapped out the entire transmission network for the platform. I abandoned the leg-design of the Spider entirely.
Anti-Gravity Arrays: I designed a baseplate covered in high-frequency "Magnetic Repulsion" runes. By using Magnet Release to oscillate the field at 40,000 Hz, I could create a stable air-cushion that would allow the platform to hover three feet off the ground, regardless of terrain.
Vector Propulsion: I added six independent thruster ports that used Wind Release to provide 360-degree high-speed maneuvering. By shifting the "Magnetic Polarity" of the chassis, I could achieve instantaneous lateral shifts, making the "Mirage" almost impossible to track with the human eye.
Integrated Weaponry: I designed a series of internal "Silos" for Iron Sand. Using the core's energy, I could launch "Magnet Release: Iron Sand Prisms", high-velocity projectiles that could be steered mid-flight like guided missiles.
Stealth Module: By vibrating the magnetic field at a specific "Invisibility Frequency," I could potentially warp light and sound around the chassis, making it a true ghost in the sand.
I spent hours on the math, demolishing and restarting the logic until every interface was clean. I calculated the aerodynamic drag of the shuttle-shaped chassis and the thermal dissipation required to keep the Natural Energy core from melting the wooden frame. I used a combination of "Chakra-Conductive Lead" and "Iron-Oak" to build a chassis that was both light and shielded.
Finally, I connected the final weapon-system lead to the core hub on the paper. I sat back, the oil lamp flickering in the early morning light.
The Preliminary Design for the Mirage was complete.
It was a strategist's dream, a manned, high-speed combat platform that surpassed every current puppet concept in the Ninja World. It integrated Natural Energy, Magnet-Levitation, and automated combat scripts into a single, lethal package. It was no longer a "Toy" or a "Pack Animal." It was an Interceptor.
I looked at the blueprint, the culmination of two lives, thousands of hours of effort, and all my current hopes. My eyes were shining. The "Gundam" of my dreams might still be out of reach, but this "Mirage" was the first pair of wings I'd ever truly owned.
The Hidden Sand was hunkering down, preparing for a war of attrition. But as I rolled up the scroll and felt the Jonin-level power humming in my veins, I knew I was no longer just a participant in their war. I was the one who was going to change the game.
"Mirage Protocol," I murmured. "Initialization complete."