Infinite Evolution of Kamen Rider

Kamen Rider Decade, much like Zi-O, is themed after a knight—though instead of golden armor, his dominant color is pink… or as one unnamed Rider insisted, magenta.

There's even a saying: "He looks pink when alone, but next to Zi-O, he's clearly magenta."

"Stop it! I have to help Geiz!" shouted Sougo, struggling against Tsukasa's relentless assault. His voice was urgent—he feared Geiz would be killed by Kasshin if he didn't act soon.

"Not happening! I'm not letting you through!" Tsukasa smirked confidently, sword at the ready.

"Why are you stopping me?!" Sougo shouted in frustration.

"Good question. Why am I stopping you?" Tsukasa responded with mock curiosity, speaking half to himself.

"Don't mess with me!"

"Honestly, I'm still figuring that out myself," Tsukasa admitted nonchalantly.

What kind of person acts like this? Doesn't even know why he's meddling in someone else's life? A complete wildcard. The kind of guy you'd diagnose with some serious anti-social tendencies.

[KamenRide!]

[Build!]

[The Moon of Steel returns!]

[Rabbit–Tank!]

With a flourish, Tsukasa slashed his Ride Booker through the air, calling upon the power of Kamen Rider Build and transforming in a burst of colored energy.

"Build? Then I'll match you!" Sougo responded, pulling out a new Ridewatch—Decade.

The moment Sougo slotted the Decade Ridewatch into his Ziku-Driver, he unlocked the ability to stack Decade's power on top of any two existing Rider powers.

[ArmorTime!][KamenRide!][Decade~~!]

Zi-O's armor morphed into a Decade-style form. Though it mirrored Decade's structure, it was… disappointing. The flat, pancake-like faceplate made it look awkward—almost like a bootleg design.

"Oh? Isn't that my Ridewatch?" Tsukasa asked knowingly, feigning surprise.

"Not just that—this too!" Sougo shouted, inserting the Build Ridewatch into the slot atop Decade Armor.

[Build!][FinalFormTime!][Bu-Bu-Bu-Build!]

The Decade Armor evolved. Its helmet display switched from "Decade" to "Build," and blue-and-red rabbit-tank armor appeared across his limbs in a holographic bubble style. Though impressive, it was clearly a transitional upgrade.

While Tsukasa was only using the base forms of the Riders, Sougo was wielding enhanced forms—amplified through Decade's framework.

At that moment, Sougo gained the upper hand—barely. He finally managed to land a finishing move that knocked Tsukasa back.

But before Sougo could celebrate, Tsukasa reverted to his base form and counterattacked with such overwhelming power that Sougo was pushed onto the defensive again.

Why was base Decade stronger than this powered-up hybrid? The only possible explanation—one whispered by Woz watching from afar—was that the original Decade's base form inherently suppressed Sougo's borrowed power.

Still, Sougo had achieved what he set out to do: stop Kasshin from killing Geiz.

Seeing his master faltering, Kasshin broke off from his assault on Geiz and rushed to defend Tsukasa.

"What the—so he is your ally?" Tsukasa mocked as Kasshin stood protectively between him and Sougo.

"No!" Sougo snapped, offended.

"Really? Sure looks like it!"

Their argument was so absurdly childish that Woz sighed from the sidelines. Must they bicker like a couple fighting in public?

"Gates! I need help over here!" Tsukasa shouted suddenly. Geiz, catching his breath, barked back:

"Stay out of it! I'm killing Zi-O today!"

"Gates, he's with the Time Jackers!" Tsukuyomi warned.

Since Tsukasa had been siding with Uhr since the beginning, everyone assumed he was a Time Jacker ally.

As for Woz… he had helped Sougo before, so despite his strange allegiance to Ora, the others half-accepted him as "one of ours."

"If he can help us take down Zi-O, I don't care if he's the enemy," Gates said bluntly.

"Stop it! I'm only trying to help you, Geiz!" Sougo shouted. Kasshin blocked Geiz's path again, and Tsukasa charged back at Sougo.

Just like that, the battle reset—same players, same positions. Nothing changed.

"You still don't get it," Tsukasa said, slipping into one of his trademark speeches. "Your true ally isn't Gates—it's your follower."

"That guy is not my follower!" Sougo snapped, casting an annoyed glance at Kasshin.

"Your Majesty, please accept it. Don't let small things block your road to kingship. This is the Sougo I know!" Woz chimed in, as if reading from scripture.

"No!" Sougo retorted. "I won't abandon Gates, and I won't let this world fall into chaos!"

"Then go see for yourself," Tsukasa said coldly. He slashed the air, summoning a Dimensional Wall, which swallowed Sougo whole.

"Sougo!" Tsukuyomi yelled, diving in after him. Woz followed suit.

This was Woz's opportunity. While he could travel through time and space on his own, he lacked the precise coordinates to reach that future. If he tried alone, he might end up in some random parallel world. Letting Tsukasa do the work was much safer.

"Huh?" Tsukasa blinked, feeling Woz's energy trail right behind. "Didn't expect that." But he had no interest in joining them. Seeing the Old Demon King again? No thanks. That guy was too strong. Not human.

Year 2068 – Before Sougo Became a Statue

"Where am I…?" Sougo groaned, clutching his head as he stood up.

In front of him stood a massive stone statue—of himself.

"Huh? That's… me?" He read the inscription aloud: 'Tokiwa Sougo's first petrification.'

On either side stood statues of all the Heisei Riders.

"Then this place must be…"

"Yes," Tsukuyomi's voice said behind him. "This is the year 2068. Fifty years from your own time. This… is the world where you became Oma Zi-O."

"No way…" Sougo staggered backward, then turned and ran.

"Where are you going?!"

"I have to see what this world's become!"

Sougo raced across mountains and rivers until he reached a crumbling city—half in ruins, with survivors clustered in tent cities. It looked like a post-war refuge.

"This can't be real..." Sougo whispered, stunned.

"They're lucky to be alive," Tsukuyomi said quietly beside him. "The population is barely half of what it was."

Sougo opened his mouth to respond—then a mechanical red dragon swooped in, wrapped around them both, and whisked them into the sky in a flash of crimson light.