Time at the Puppet Workshop was productive, but it was also a daily reminder of my biggest bottleneck. Like a high-end AI running on a calculator battery, I had all the "software" to design a war machine, but I didn't have the "juice" to actually turn the key.
Every day, I watched the senior craftsmen. They'd pour massive amounts of chakra into a puppet core, driving multi-meter tall combat frames through high-speed maneuvers. They could make those wooden monsters spit fire or launch a hundred poison needles in a second. Compared to them, my "Spider" was a cute hobby project.
The gap between my design capacity and my energy output was a canyon I couldn't jump across. I was sick of it. I had to rebuild this body from the ground up.
I spent my nights scouring the medical texts Granny Chiyo gave me, looking for anything on "constitution repair." The news was grim. Traditional Medical Ninjutsu was great for fixing a hole in your chest, but it was useless for a "factory defect" like my heart and lungs. It was like trying to fix a bad motherboard by polishing the case.
I was sitting at my workbench one afternoon, watching a massive energy core spin up for a test. The hum of the chakra was intense, stable, and powerful. It made me think of an old movie from back home Steve Rogers stepping into that transformation pod as a scrawny kid and stepping out as a super-soldier.
External energy infusion, I thought. Chakra is just energy. It can destroy, but it can also heal. Why can't I just "plug myself in" and let a high-output core baptize my cells until they work right?
I brought the idea to Granny Chiyo under the guise of a "theoretical question" about energy environments.
She shot it down before I could even finish. "It's an interesting thought, Sayo, but it's a death sentence. Chakra isn't neutral power; it carries the spiritual imprint of the person who made it. Foreign chakra is basically poison. If you try to force-feed your cells someone else's energy, your body will reject it so violently you'll liquefy your own organs. The path is closed."
I tried Sasori next, asking about energy conversion. He didn't even stop carving his puppet's eye. "Flesh is a design flaw," he said, his voice as cold as ice. "Why waste time trying to fix a body that's destined to rot? If you want real power, abandon the skin and embrace the puppet. That is the only 'eternal' way."
Two masters, two hard "No"s.
I sat at my bench that night, feeling the weight of despair. Rejection. Decay. Was I really stuck in this low-spec meat-suit forever?
I leaned back, my mind racing through everything I'd ever seen, read, or designed. My brain started cross-referencing my old-world memories with my new-world physics. I thought about power grids, converters, and then out of nowhere a memory of an old Chinese animation I'd watched caught fire. Under One Person. Ma Xianhong. The "Body Tempering Furnace."
In the show, that machine could convert the powers of "Outliers" and even give regular people abilities. Its core logic wasn't just "shoving energy in" it was about conversion and harmonization.
My eyes snapped open. I almost knocked over my inkwell.
"Middleware," I whispered, my breath ragged. "I don't need an infusion. I need a conversion layer."
The problem Chiyo pointed out was the "spiritual imprint" the "metadata" attached to the energy. If I could build a "furnace" that functioned as a relay, it wouldn't matter where the energy came from. The device would take raw power Natural Energy from the environment, Tailed Beast chakra from Shukaku, or even the combined output of multiple ninjas and it would purify it.
It would strip the "metadata," neutralize the imprints, and convert the messy, personal energy into a pure, neutral "Life-Energy" stream. Then, the furnace could precisely and safely drip-feed that energy into my cells, mending the "factory defects" and forcing my potential to awaken.
It bypassed the rejection problem entirely.
"The Body Tempering Furnace," I breathed, my heart hammering against my ribs. "That's it. That's the project."
It was a moonshot. It would require Master-level Sealing for the conversion logic, high-tier Puppetry for the casing and "hardware" interface, and top-shelf Medical Ninjutsu to guide the energy through the human meridian system. It was the most complex engineering project I'd ever even dreamed of.
But for the first time in two lives, the path wasn't just open. It was clear.
I forced myself to sit down and pick up my pen. I didn't care how long it took. I didn't care how many failures I had to go through. This was my life's work.
Step one: Design a stable energy core that can handle the conversion.
I looked at the blank scroll on my desk. The blueprint of my dream was finally starting to take shape. I was going to fix this body, even if I had to rewrite the laws of biology to do it.