Karl's hands hovered over the organized blueprints, Vythra flowing along his fingers like a living current. The panels shimmered, shifting in response to his intent. With a deep breath, he reached forward and let his Vythra extend into the first components of the mech frame — the skeletal limbs, the core chassis, the substructure for the engine compartment.
For a heartbeat, everything seemed perfect. The limbs aligned, the joints rotated smoothly, and the nanites followed his mental commands almost instinctively. Karl's chest swelled with pride. "This… this is it! I'm actually doing it!"
But then, a subtle misalignment began to ripple across the right arm. The elbow joint twisted slightly, like a miniature gear skipping teeth. The chassis core quivered as the nanite flow hesitated, pulses of blue energy flickering unevenly.
Karl blinked, unsure. "Wait… what did I do wrong?" He concentrated harder, pouring more Vythra into the frame, trying to force the components back into alignment. But the harder he pushed, the more erratic the nanites became. Sparks of kinetic energy arced briefly across the skeletal structure, causing the floating blueprints to tremble and shift.
A faint, calm voice whispered inside his mind — Ayaka's intuition from the Engine Soul. "Steady, Karl… don't force it. Let it flow, not fight."
He exhaled slowly, letting the guidance of his parents temper the raw energy surging through him. He pulled back, reassessing the structure in pieces rather than as a whole. Slowly, he reconnected the arm, letting the Vythra pulse rhythmically instead of rushing. The skeletal joint clicked into place perfectly this time.
Karl let out a relieved breath, but the relief was short-lived. As he tried to extend the legs, he noticed the nanite tendrils forming the hip assembly resisted his command, curling in unexpected directions. The chassis rocked slightly, almost tipping over. Each correction seemed to spawn another tiny problem, forcing him to start adjusting multiple sections at once — arms, torso, legs, all feeding into a chaotic feedback loop.
His heart raced. "It's… it's too much all at once!" The Vythra in his Rider form's body pulsed unevenly, reflecting his mental stress. He felt the faint pressure of the Gear Drive stabilizing his mechanical movements and the Engine Soul tempering the energy output, but even their combined support couldn't fully compensate for his inexperience.
Karl gritted his teeth. "Okay… think, Karl. Step by step. Not everything at once."
He shut his eyes for a moment, letting the floating blueprints and nanite components "speak" to him, letting the designs guide his hands rather than forcing them. Slowly, deliberately, he began reassembling the skeletal frame, limb by limb, joint by joint, learning the subtle dance of control between Vythra, Engine Soul, and Gear Drive.
The first attempt had been messy, chaotic, almost destructive, but even amidst the turbulence, Karl felt something exhilarating: he was learning. He was creating.
And in the Nexus of Creation, every misstep was just another spark lighting the way toward perfection.
Karl exhaled through his teeth, wiping the phantom sweat from his brow. The first frame hovered before him — skeletal, half-fused, twitching with mismatched impulses of light. Each limb trembled like it was alive but unsure what it was supposed to be.
He frowned. "Alright… it's not the shape that's the problem — it's the flow. The Drive Regulator isn't syncing with the frame's pulse."
He placed his hand against his chest — right where the Drive Regulator hummed beneath his armor plating. The faint rhythmic chime of the regulator pulsed steady, controlled. The mech frame, however, pulsed wildly, every beat slightly off-tempo, like a second heartbeat trying to fight the first.
Karl closed his eyes, projecting his consciousness into the blueprint. "Alright, let's do this manually."
Panels of blue data unfolded around him — circular arrays of schematics orbiting his body. The frame's skeletal diagram split apart into layers: actuator systems, energy conduits, gear-link nodes, then finally the Blueprint Mechanism Core, glowing faintly at the center like a digital heart.
Karl reached toward it, his Vythra threads linking between his fingers and the floating core. "You're not separate systems," he muttered, half to the machine, half to himself. "You're one unit. The frame isn't just mine — it is me."
He willed the Vythra streams to flow inward, connecting the core to the Gearheart Core embedded within his chest. For a moment, they synced — his pulse and the core's rhythm aligning in a sharp, perfect beat. The mech frame trembled, its limbs aligning in a cleaner, smoother motion.
But then — resistance.
The frame's energy signature suddenly spiked, sending feedback up the conduit. The backlash hit Karl like a physical punch, knocking him back as arcs of nanite energy burst from the contact point. Blueprints scattered into static, reforming chaotically around him.
Karl gritted his teeth, forcing his stance. "You want to resist? Fine. Then I'll tune you to me."
He snapped his hands forward again, the Drive Regulator on his belt whirring with a heavy mechanical churn. The regulator's pulse deepened, matching his rising determination. He began re-synchronizing the feedback flow — channeling the excess Vythra into smaller calibration cycles instead of direct input.
Slowly, the surges began to stabilize. The chaotic flashes along the mech frame dulled into a steady, breathing glow. The limbs no longer twitched — they responded. The torso aligned. The joints folded inward with mechanical precision.
Karl's eyes lit with a fierce grin. "There we go… yeah, that's it. Come on, sync with me—"
The final spark connected. For a brief, dazzling instant, the mech frame's energy harmonized completely with Karl's Drive Regulator. The core of the frame pulsed once — clean and bright — before going dormant again, perfectly stable for the first time.
Karl let out a long breath. "Hah… that's better. Not perfect, but at least it's not trying to explode in my face anymore."
The disembodied voice of Hephaestus echoed faintly from above, carrying a smirk in its tone.
Hephaestus: "You learn fast, boy. But don't celebrate yet. You've merged your regulator and the frame — now you need to prove they can sustain each other."
Karl looked up at the half-complete mech, its glowing eyes dim but steady. "Right. Stability's only half the battle."
The Nexus pulsed brighter, the air thick with potential — as if the realm itself waited to see if the mortal and machine could truly become one.