Night fell over Fuyuki like a heavy curtain, smothering the city in shadows. Under that cover, Tsutsumi and Artoria moved through the quiet streets.
Tsutsumi had finally decided to give his Servant more mana. Not because he trusted her, but because her being useless in a battle and getting in his way would be far more annoying than the risk of empowering her.
As Wizard, his magical awareness was sharp, sharper than anything this era's decaying magecraft could produce. In a world where magic had thinned to a dying whisper, any surge, any spike, any flare of magic energy was almost guaranteed to be the presence of a Heroic Spirit.
And tonight, the spike was close.
They landed on the ground near a deserted playground. The air was unnaturally still.
A young girl stood on a swing, snow-white hair, crimson eyes, and a purple German winter dress that looked almost too clean, too pristine, for a child playing outside at night. Her tiny hands gripped the chains as she swung gently back and forth.
Her gaze locked onto Tsutsumi. She smiled. A smile he instantly recognized as fake.
"Oh? I didn't know Daddy's little tool was such a capable weapon…" she said, her voice calm and disturbingly sweet. She hopped off the swing with unnatural grace. "So… how about you play with Berserker, Onii-san?"
The air to his left twisted violently, magic thickening like a sudden storm.
Tsutsumi turned just in time to see a hulking figure materialize, a massive man with obsidian-black skin, muscles like carved stone, and a colossal stone-like sword already mid-swing.
Final Kamen Ride: Blade! King!
The strike hit like a meteor. Dirt and gravel exploded as Tsutsumi skidded across the ground, his King Rouzer digging long, heavy gouges through the earth.
He straightened, eyes narrowing at the towering monster now standing protectively beside the little girl.
"Tear him to pieces, Berserker!" she cheered, almost giggling with joy.
Berserker roared and charged. Each step shook the ground, a rhythm of doom pounding toward him.
Final Attack Ride: Bl-Bl-Bl-Blade!
Tsutsumi swung his weapon. A golden energy slash ripped through the night, passing through a line of golden cards before slamming into Berserker's chest.
The monster was thrown back, then split cleanly in half.
The air stilled for a moment.
Tsutsumi turned toward the girl. She was still smiling. Completely unbothered.
He stepped forward, dragging the massive King Rouzer behind him as its tip scraped across the concrete with a harsh metal grind.
"Oi? Is Onii-chan going to hit me?" she teased, clasping her hands behind her back. "So scary… I'm gonna tell Mommy and Daddy."
The ground trembled.
Tsutsumi's eyes widened a split second before he was blasted off his feet, his body launched backward, crashing through a cluster of trees and splintering trunks like matchsticks.
He pushed himself up, coughing dust.
The same hulking Servant he had just cleaved apart stood before him again, fully regenerated, roaring with even more fury than before.
"What the?" he muttered, right before Berserker charged again.
A clang rang out, sharp and bright, as Artoria appeared in a flash, her blade intercepting Berserker's massive sword. Sparks burst into the air with every clash, the force of Berserker's strength shaking the ground beneath them. Before he could follow up with another strike, Artoria leaped backward.
Final Attack Ride: Bl-Bl-Bl-Blade!
Tsutsumi shot forward, his heel slamming into Berserker's chest. The impact sent the gargantuan man flying before detonating into a violent explosion.
But just like before, Berserker stood up again. His injuries heal in the blink of an eye. It let out another massive roar.
"Tch! It won't die normally, huh?" Tsutsumi muttered, pulling another card with irritation, sharpening his gaze.
Final Form Ride: W! Xtreme!
Golden armor shattered off his body like falling scales, replaced with a long coat and sharp tri-colored clothing, green, white, and black, moving from right to left.
The night wind curled around him as the transformation settled.
And Berserker howled, ready to charge once more.
The white half of Tsutsumi's clothes began to glow, faint symbols crawling across the fabric like living lines of data. The world blurred for a moment as he tapped into the Gaia Library, pulling information straight from the planet's record.
Servant: Berserker
True Name: Heracles
Master: Illyasviel von Einzbern
"So I'm fighting a literal demi-god with twelve lives who can only be harmed by A-Rank attacks..." Tsutsumi muttered. His tone held no fear, just pure, flat annoyance. The kind that said this is a chore.
He shifted his gaze back to the little girl staring at him with those crimson eyes.
Illyasviel von Einzbern... Daughter of Irisviel von Einzbern and daughter of Tsutsumi Akirameta, the man who adopted him back in this world.
"So that's why she calls me that..."
The pieces clicked together.
Illyasviel wasn't calling him "Onii-chan" for fun. It's more like she is trying to mock him. The Einzbern had poisoned her mind, fed her the idea that her father had abandoned her, while preventing any chance for them to meet.
Still… Illyasviel wasn't Miyu. And aside from sharing the same father in this world, she meant nothing to him.
His eyes sharpened.
Tsutsumi dashed forward with Artoria at his side, summoning the Prismbicker. The shield unfolded; he drew the sword from its center, and the two charged Berserker together.
Saber met Berserker head-on, their weapons clashing with a force that sent ripples through the ground. Her blade slid across his stone sword, sparks spraying in the cold night air.
Berserker abruptly let go of his weapon, his massive fist snapping forward toward Artoria's stomach, but Tsutsumi stepped in front of her, the Prismbicker shield raised.
A burst of colored light, purple, red, yellow, green, fired point-blank, detonating against Berserker's chest and blasting the giant backward.
Tsutsumi didn't spare him another glance.
His eyes were on Illyasviel.
With cyclone speed and a blade ready to sever her head from her shoulders, Tsutsumi sprinted for her. Why waste effort killing a twelve-life demi-god the proper way when he could end it much faster?
Illyasviel's expression twisted, panic replacing confidence.
"Berserker!!"
She shouted, and the black giant appeared right before him, roaring loudly and swinging his massive stone-axe blade down on him.
Final Attack Ride: J-J-J-Joker!
Tsutsumi ducked under the swing. Purple flames erupted around his fist before he drove it forward, tearing straight through Berserker's guts.
The Joker Gaia Memory relies on the user's emotions to determine its power. The more powerful the user felt when doing something, the more power the Gaia Memory with give out.
This works like the Hazard Level in Build. The more intense your emotions are, the higher your Hazard Level will increase and the stronger you become.
Berserker's torso exploded outward, and yet the hulking giant roared back to life again, regenerating instantly.
Artoria stepped in with a burst of Mana Burst, slamming Berserker away, then retreating behind Tsutsumi with a deliberately measured distance, doing just enough to seem useful while letting her Master do the real work.
Illyasviel began to feel worried, seeing that Berserker had already lost three lives, and each one of them was taken by her step-brother, not his servant.
The thought of a regular human defeating a Servant is already very impressive, but being able to even kill Heracles three times without breaking a sweat is unthinkable.
It shouldn't even be possible to begin with. Heracles can only be damaged by A-Rank Noble Phantasms, crystallized legends taking the form of a weapon. Or at least, something was the same power as an A-Rank Noble Phantasm.
"Berserker! Retreat!!" Illyasviel shouted, fear finally cracking her voice.
She looked like a child realizing the monster she threw a rock at was actually looking back.
And moving toward her.
The hunter had become the prey.
Berserker tried to reach her, but Artoria stepped into his path, slashing to slow the black giant down.
Tsutsumi prepared to close in, but a rain of arrows suddenly descended from above, forcing him to leap back.
His eyes snapped up.
"Archer," Was the word that escaped his lips.
A good distance away, the red-cloaked Archer with white hair and tan skin locked eyes with him, and the two stared at each other before he summoned another arrow and fired it toward Tsutsumi. With the arrows coming his way and Berserker closing in, Tsutsumi pulls out a card.
Kamen Ride: Wizard! Hi-Hi, Hi-Hi-Hi!
Berserker quickly takes Illyasviel and uses his superhuman speed; he runs off with her in his hand. A crimson magic circle appears before Tsutsumi, blocking the arrows from hitting him.
He then pulls out another card.
Final Attack Ride: Wi-Wi-Wi-Wizard!
Seeing that Illyasviel had escaped, the red Archer was about to leave, but the moment he turned back, he saw a massive hand already swinging toward his face.
"What the-"
He didn't finish the sentence. Tsutsumi's oversized magical hand bitch-slapped him, launching him across the plaza like a ragdoll.
Tsutsumi pulled his hand back through the magic circle, returning to normal.
Behind him, Artoria spoke.
"I'm hungry..."
"You just ate an entire restaurant out of stock. I'm not buying more." He reminded her.
Before pulling out a card from his pocket.
Form Ride: EMIYA (Archer)
Back then, only EMIYA got properly killed by him using Artoria's Excalibur Form; he didn't cut off his link with his master like the other EMIYA. In a way, throughout that fight, only EMIYA Archer died; the other suffered emotional damage.
It could be said, Decade Violent Emotion is one of the most dangerous Kamen Riders. Even when Tsukasa becomes Decade Violent Emotion, the only fight he really lost is by his own decision, letting himself be harmed and stabbed, and he didn't even fight back.
Tsutsumi sighs, putting the card away.
He placed his hand on his head and began to think back on what he saw from using the Gaia Library. With it, he can read and find out anything on this planet, all events that have ever happened.
With it, he could see Heracles's journey, Illyasviel's birth, her mother's death at the hand of her father, EMIYA's strategy, who his master is, even the fact that Artoria got drunk, had Merlin give her a dick, and got used by her older sister was laid out to him.
It could be said that this ability is very useful...
"I wonder..." he murmurs as a sudden thought flickers across his mind.
After returning home with his servant, who instantly reverted to her cold burrito form the moment they crossed the threshold, Tsutsumi slipped back into his own world, reappearing in the quiet stillness of the training forest.
And then he used Xtreme again. This time, he headed straight for the Gaia Library.
A blank world unfolded around him, a horizonless white space carved apart by endless towering bookshelves, stretching so far and so high they seemed to scrape the untouched sky. Countless books, countless histories, carrying the weight of the world's knowledge.
"Keyword: Tsutsumi Kaina."
The response was immediate. Every shelf trembled and then lurched into motion, sliding at blurring speed like pieces of a titanic puzzle rearranging themselves around him. After a moment, fourteen books extended outward from their rows like drawn blades.
Tsutsumi's eyes flicked across them, ignoring the unfamiliar titles. He noticed the books bearing his name and his sister's, but his gaze locked on only one:
"Tsutsumi Kaina." His mother.
He reached toward it. But a hand snatched the book away before his fingers touched it.
"What the?" Tsutsumi jerked back, eyes narrowing at the sudden intrusion.
A man stood before him, taller, wearing black and magenta, colors that twisted together as sharply as his presence. His hair was a gradient of purple and magenta, familiar in a way that made Tsutsumi's heartbeat kick.
The man grinned lazily. "Yo, my past self."
He was Tsutsumi Ryoko. From the future.
"You are me?" Tsutsumi whispered, the words coming out stiff with disbelief.
"Bingo," future Tsutsumi replied, flicking the book casually in his hand.
And then Tsutsumi noticed it, which had felt off from the moment he appeared. The future him wasn't wearing the Decade Driver at his waist.
Before Tsutsumi could process that, he stepped forward. "Before you tell me your reason for coming here…" He extended his hand. "Hand me that book."
"You're not ready to see its content," future Tsutsumi said without hesitation.
Present Tsutsumi's eyes sharpened. "What the hell do you mean by that?"
"What I mean is… you aren't ready for what's inside this book." His tone was still casual, but there was something behind it, a heaviness Tsutsumi had never heard in his own voice.
And then, the library shattered into white light.
Tsutsumi gasped and opened his eyes. He was standing in the training forest again. His future self leaned casually against a tree, looking completely unbothered.
Tsutsumi immediately re-entered the Gaia Library, only for his stomach to drop.
The book about his mother lay there ruined, torn apart, every page ripped out and missing as if someone had deliberately erased her story.
He returned to the real world slowly, fists clenched. And his future self was still there. Still smiling.
Smiling like he already knew what Tsutsumi had discovered.
"Henshin!"
Form Ride: Decade!
Tsutsumi charged, fury igniting through him.
Future Tsutsumi finally stood up straight. He pulls out a magenta-colored Decade Driver, clasping it onto his waist in one smooth motion. Then he pulled out a card with the ease of someone who had done this countless times.
"Henshin."
Kamen Ride: Decade!