The project of transplanting magic circuits lasted three full days. During that time, Doraemon used the [Time Wrap] countless times. Apart from eating and sleeping, man and raccoon-cat devoted themselves entirely to this dangerous experiment.
Miyamoto Musashi came by several times during the process. Each time, she sensed that her Master was tinkering with something far too dangerous for comfort. After issuing a few stern warnings, she chose to remain with the Matou family rather than interfere further.
Three days—hardly enough to prepare even a minor ritual in the eyes of most magi. Yet what Shirou Muramasa accomplished in that span rivaled the very system of the Holy Grail itself. A miracle, by any standard.
By endlessly rewinding time with [Time Wrap] and boosting his body with the [Efficiency Enhancement Pill], Shirou succeeded in transforming the [Famous Sword: Lightning Pill] into a magic seal woven from countless circuits.
Even Doraemon no longer recognized the blade. Its original form had collapsed under the weight of its accumulated circuits, reconstituting itself as a glowing, emerald-green sword-shaped crest—80% identical to the Command Seals etched into Shirou's own hand.
Layer upon layer: the sword as the base, the circuits as framework, carvings upon carvings, accumulation upon accumulation—until the weight of quantity forced a change in quality.
The seal now drew magic endlessly from the Great Source. Even Berserker Musashi, with her monstrous consumption, could barely keep pace with the torrent of prana it devoured.
It was less a crest and more a mobile spiritual vein, so vast in presence that the magi of Fuyuki would have noticed it long ago—if not for the protection of this mirror world.
Inside the quiet chamber, Shirou and Doraemon stared at the suspended seal. Even Doraemon, who knew nothing of magecraft, could feel the suffocating power radiating from it. Just looking at the crest evoked the piercing illusion of being run through by a thousand blades.
Shirou knew instinctively—this was his limit. The Lightning Pill had reached the boundary of what a human could possibly endure.
He steadied himself, body and mind aligned, then turned to Doraemon. His eyes were serious."Doraemon. You and Musashi need to leave. Keep at least one kilometer away."
"I understand."
Doraemon didn't argue. He had seen firsthand the agony Shirou endured each time he invoked [Time Wrap]. He had once asked Musashi about it. Her response was blunt:
"It's the sort of pain you'd never want to feel again once you've experienced it even once."
This time, Doraemon hadn't been pleased with Shirou's reckless resolve. He had scolded him, even. But in the end, Shirou's stubborn gaze had won out, and the blue cat continued to aid him in forging the crest.
Even Shirou was startled by his own endurance. His desire to complete the seal—and the pull of the sword's origin within him—completely drowned out the pain of circuit transplantation.
"Shirou, be careful. I'll leave this surveillance device to monitor your condition." Doraemon placed a camera on the ground, then reluctantly stepped out, glancing back with every step.
After a long silence, Shirou spoke again. "Musashi. Do you have anything to say?"
From the doorway, Musashi rested one hand on her hilt, releasing an aura sharp enough to slice the air."Master. You're hesitating."
Shirou frowned.
"Because I am my Master's sword, I can feel it. This trip is to sever that hesitation."
Shirou's gaze lingered on her slender figure, then he admitted quietly:"I can't tell if this crest was born of my own will… or if I've simply been consumed by the sword's origin."
Musashi tilted her head. "Is there a difference?"
"Yes." His reply was firm.
She smiled. "Master, do you remember what you once told me? That because I had the Sky Eye, I could never reach the seat of Space?"
A faint laugh escaped Shirou. "The more you see, the more concerns you have."
"Exactly. My weapon is the sword. Your weapon… is me. My duty is to cut away every obstacle in your path."
She stepped behind him, ruffled his red hair with a playful grin."You're still a fledgling bird, Master. Right or wrong, good or bad—only through tempering can you grow. And if something happens, don't you have Doraemon and me?"
Her tone softened."Never forget—I am your Servant. Lean on me a little more."
With that, she turned and left the chamber.
Shirou steadied his breathing. Musashi might look like a ditzy girl-next-door, but when it counted, she was unshakable.
He swallowed another efficiency pill and reached for the seal.
Swish—
A storm of emerald blades erupted. In that instant, Shirou felt himself pierced by countless swords, his circuits drowned in a flood of power. The origin itself pressed down upon his soul.
He was a lone boat adrift in a raging sea, yet his spirit held fast. Under the pill's focus, he seized control of the crest.
"Affirm, affirm, affirm—until compatibility."
"Negate, negate, negate—until dominance."
"One, two, three… countless."
"Erosion, resistance, melting, concealment."
Turquoise blades burst from his body, filling the chamber and tearing the Matou estate to splinters. In its place, a colossal jade tree bloomed, dozens of meters high, every branch humming with lethal sword-magic.
Anything it touched would corrode, then sprout with blades from within.
"This—this—this!!"
From a safe distance, Doraemon screamed, running in frantic circles. His surveillance feed fizzled into static.
Musashi, however, only smiled faintly."As expected of you, Master. Truly impressive."
"Shirou, are you okay!?" Doraemon was on the verge of tears.
Musashi lifted a brow. "Tōraemon—believe in my Master."
But Doraemon was panicking too hard to listen.
If Shirou failed to master the seal, Musashi was prepared to intervene, to call upon the Zero Tengen Sword that severed time and space itself.
But in her perception, despite the catastrophic noise, this was no failure. It was simply Shirou carving away the excess, refining the crest. The proof lay in the steady torrent of prana he continued to provide her.
Magic Crest — [Unlimited Blade Works]
An inherent barrier. A great forbidden spell that eroded reality itself, forged not by prana but by the sword's origin and the concept of Infinity.
"It worked."
System messages flowed into Shirou's mind.
[Unlimited Sword]
Class: EX
Type: ???
Range: ???
Maximum Targets: ???
Description:A miracle beyond replication. Formed from countless circuits embodying the sword's origin, it solidifies that origin alongside the infinite. A barrier as firm as a miniature world, one that contains the concept of every possible sword.
Within this realm, all blades may be forged. Divine weapons can be copied at over 90% of their true strength. Even when inactive, the barrier shields its wielder, negating physical, magical, and conceptual interference alike.
Its principle: the caster is drawn within the barrier itself, the infinite world as armor. Only divine constructs surpassing its concept can pierce it.
The spell grants three external applications: analysis, reinforcement, and projection—at their peak when applied to swords. Any analyzed blade becomes part of the domain. All may be recreated.
Even the Lightning Pill's unique properties may be inherited.
And since the crest is forged entirely from Shirou's own circuits, it is inseparable from him—an extension of his very body.
A version of Archer's Unlimited Blade Works—but magnified. A top-tier Noble Phantasm, rivaling the strongest. Breakable only by a fully unleashed Sword of Rupture… or something even greater.