Hephaestus extended his hand toward Karl—
but instead of forming a defined object,
instead of shaping a completed relic or weapon…
…the Nexus hesitated.
Reality vibrated.
A sphere of shifting light swirled, pulsed, and fractured like molten glass struggling to solidify.
The air thickened.
The entire infinite void dimmed.
Karl blinked.
"…Huh?"
Agnes leaned forward, squinting.
"That's… not normal…"
Even Hephaestus frowned — the first time Karl had ever seen genuine uncertainty on a god's face.
"…Strange."
The light condensed.
Shrank.
Straightened.
Edges formed.
A cube emerged.
Black.
Dense.
Veined with unstable admiral circuits that twitched like living lightning.
But it twitched wrong — as if it was still deciding what it wanted to be.
Karl felt a chill crawl down his spine.
"…What is it?"
Agnes whispered, her tone hushed with awe and fear.
"I… I don't know, Karl… this is nothing like your first milestone's reward…"
The cube floated there, vibrating subtly like it contained a storm trapped inside.
Hephaestus stepped closer.
"…The Nexus has not done this before."
Karl's breath caught.
"You mean… you don't know what this is either?"
The Primordial of Creation shook his head slowly.
"The Nexus does not give me knowledge of what reward it shapes.
It adapts on its own—
to your wounds, your limits, your failures, and your growth."
Agnes' eyes widened.
"So… this cube is based on the fight with Goliath…
It's exactly what Karl needs to survive the next time they meet."
Hephaestus nodded.
"Correct.
But what form it takes…
what purpose it serves…
that is for you to determine."
The cube pulsed violently.
And then—
KRRRRAAAAA-CHHHHHHHH.
It exploded—
—not outward,
but into blueprints.
Dozens.
Hundreds.
Thousands.
They spun around Karl in perfect synchronized orbit.
Blueprints etched in lines of circuits, engine layouts, ignition schematics, pressure channeling pipes, kinetic amplification frameworks.
Agnes gasped like a child seeing fireworks for the first time.
"K–Karl… LOOK AT THIS—
THIS IS INSANE—!!
These are… these are engine blueprints!!
Acceleration rails!!
Thermal conduits built for EXTREME output—!"
Karl blinked rapidly.
"…Is this… some kind of… turbo system?"
Hephaestus shook his head — still amazed.
"No.
Turbo systems rely on rotational force.
This is something else."
Agnes zoomed in on one blueprint, eyes sparkling.
"Karl…
Look at this channel sequence—
It's a FIRE-ACCELERATOR LOOP.
Liquid energy cycling at impossible pressures."
Karl felt a grin forming.
"So…
like a… nitro boost?"
Agnes froze.
Her avatar glitched.
Blue eyes glowing wide.
"Karl…
Karl, that's—
THAT'S EXACTLY WHAT THIS IS—!!
A NITRO SYSTEM—!!
BUT ONE THAT CAN BE INSTALLED INTO YOUR DRIVE REGULATOR—!!!"
Karl stared at the swirling schematics.
"I'm getting… nitro… on Erevos?"
Agnes screamed with excitement.
"NOT JUST ON EREVOS!!
THIS SAYS YOU CAN USE IT IN RIDER FRAME TOO—!!
AND—
AND YOU HAVE TO BUILD IT YOURSELF—!"
Karl's grin became feral.
"…Hell yes."
Hephaestus crossed his arms, still watching the rotating plans carefully.
"The Nexus has created this because Goliath nearly killed you through brute force and speed beyond your current limit.
To adapt, the Nexus is granting you a path to surpass such force."
He gestured at the blueprints.
"But note this:
nothing is finished.
No weapon is fully forged.
No engine is pre-assembled.
The Nexus gives only what you need—
the potential."
Karl nodded slowly, absorbing every word.
"So I'm not receiving a completed upgrade."
"Correct."
"I'm receiving the knowledge to build one."
"Correct."
"And I build it in the Nexus."
Hephaestus smiled.
"Correct."
Agnes twirled around him, squealing.
"Karl this is perfect—this is PERFECT!!
You literally get to CUSTOM-BUILD a nitro engine for Erevos!
AND Rider Frame!
This is like—
like giving a kid a blueprint for a rocket and telling them to 'have fun'—!!"
Karl snorted.
"I'm going to build the hell out of this thing."
The blueprints spiraled faster, merging into a single enormous holographic schematic in front of him —
taller than Erevos,
shining like a miniature sun.
Karl reached out.
The moment his fingers touched the edge—
FWOOOOOM.
Knowledge poured into him.
Not as words.
Not as tech.
As instinct.
He suddenly understood:
How pressurized energy channels worked.
How to cut the slot into the Drive Regulator.
How to design the ignition lever.
How to keep the nitro from overloading the chassis.
How to sync the capsule with Erevos' core.
Karl stumbled back, gasping.
"Oh… holy… shit…"
Agnes floated beside him, trembling with awe.
"Karl… you know how to build it now…"
Hephaestus' voice thundered through the Nexus.
"This is your second reward.
Your second Ascension."
He looked at Karl with something that almost resembled pride.
"You are no longer a Chosen adapting to danger.
You are a Chosen who will build the means to surpass it."
Karl steadied himself.
Agnes floated at his side, blazing with excitement.
Hephaestus extended a hand once more.
"The blueprint is yours.
The knowledge is yours.
The creation is your burden…
and your evolution."
The Nexus dimmed.
The cube reformed —
small, dormant, now clearly the Nitro Capsule,
awaiting its future engine.
Hephaestus spoke:
"Kurogane Karl .
Your second milestone is complete.
Prepare for your return…
and begin your forging."
The Nexus trembled.
Karl inhaled deeply.
Agnes whispered with a thrill of pure joy.
"…Karl… we're going to build a monster."
Karl smirked.
"Oh yeah."