A/N: Fair warning, I'm being very liberal with Decade's powerset, I got him access to the powers and forms of the Reiwa Era, specifically Zero-One and Geats.
"I got the gist of things."
It has been a few days since one Kamen Rider Buffa successfully culled the populace of Tokyo to a meager size, including the murder of various Kamen Riders affiliated with the Desire Grand Prix.
In one man's opinion, these Jamatos, plant-like monsters that were not unlike the Helheim monsters that Gaim fought in Zawame, were a lot worse than when Shocker managed to dominate the world.
Yes, humanity wasn't free in those times, but none were also running for their lives whenever one was spotted. Even the monsters that Shocker has created didn't indiscriminately attack the populace, at least they don't attack the people in crowded and public places.
However that situation wasn't ideal, nor was the current one.
"It's time to destroy this world."
"You're Buffa?" A man in pink clothes walked up to the man wearing black clothes.
"Who's asking?" The man growled in response.
"Just a passing through Kamen Rider, remember that." The man presented the card to the man opposite him and placed it inside his belt buckle. "Henshin."
"The man glowed pink before he was encased in pink armor with a helmet that looked like a barcode."
"Another Kamen Rider? Perfect!" The man in black clothes – Buffa – presented a purple buckle and placed it on his belt.
"Set"
"Henshin"
Buffa glowed purple as a zombie-like armor materialized beside him before it was pulled into his person with a bull-styled helmet falling on his head.
"They weren't kidding when they said you were a bullhead."
Buffa ignored the pink Rider's remark and immediately rushed at him with his chainsaw and began slashing at him from every direction.
"And you're just proving their point."
"Attack Ride: Slash"
The pink Rider blocked every slash with his oddly-hilted sword with ease before hitting the zombie Rider with the same sword.
"Stay still!" Buffa growled, ignoring the hit took as he brought down his chainsaw from above the pink Rider.
"How about," The pink Rider jumped back. "No."
The pink Rider placed a card on his belt like he did when he transformed earlier.
"Attack Ride: Illusion"
Three more copies of the pink Rider emerged and rushed at Michinaga.
"Coward! Fight me yourself!" Buffa yelled as he took down the copies of the pink Rider but one escaped destruction and he took advantage of the bull's vulnerable back and slashed the zombie Rider's back.
"If I remember correctly, you did not earn your victories yourself," The pink Rider clicked his tongue. "You triumphed over Tycoon while he was distracted from the world-shattering scene he witnessed and you snatched victory from both the producer and Geats when they were distracted with each other."
"Who cares?! I won! That's it!"
"Then why should I fight fairly, as the other two did?"
"I will destroy every last one of the Kamen Riders and destroy this ridiculous world made of Kamen Riders!" The bull-themed Kamen Rider flailed his chainsaw around in an attempt to hit the last copy.
"You're right about one thing, this world will be destroyed, but not by your hand, Buffa."
"Oh, so you admit that you're the destroyer of worlds, Decade?"
"Narutaki."
"That's it, Buffa, Kamen Rider Decade will destroy your ideal world if he continues to exist, destroy him before he destroys yours!"
"Must we dance to the same tune, Narutaki?"
"I was right! Kamen Riders are the blight of this world!"
"That's where your wrong, Buffa."
"Kamen Ride: Ichigo."
The pink Kamen Rider – Decade – transformed into a different Kamen Rider altogether, he was now wearing green armor with a grasshopper theme.
"Narutaki is right, I am a villain, but these Kamen Riders are heroes."
Decade, in Ichigo's armor, rushed at the purple Rider and disarmed him of his chainsaw.
"A lot of these Kamen Riders did not choose to be one, they were chosen to be one."
"Kamen Ride: Kuuga."
"Once chosen, they fight to protect the smiles of others."
Decade, now sporting red armor, parried all of Buffa's strikes while simultaneously kicking the chainsaw away from its owner.
"Kamen Ride: Ryuki."
"They rise up to the occasion and fight."
"Ja-ja-ja Strike"
"Attack Ride: Guard Vent."
A draconic shield appeared on the new form's shoulders that defended Decade from the vines that the bull rider summoned.
"They refuse to let others be sacrificed."
"Attack Ride: Strike Vent."
A dragon's mouth fell on Decade's right hand and fire was spewed by it, burning the summoned vines to ashes.
"Form Ride: Heat Metal."
"At times, it is at their own expense."
Decade, now wearing a red and silver armor split down the middle, used his metallic staff to parry any and all other summoned vines and burned them as soon as they made contact.
"Kamen Riders are all selfish scum of the world."
Buffa growled as he made use of one of the vines to retrieve his weapon from the ground.
"Poison Charge."
"They should all be destroyed."
The purple rider brought down the spinning chainsaw on Decade, who had been changing from one form to another.
"If not for these Kamen Riders, Tohru would have –"
Decade brought his metallic staff up and blocked the strike from the bull Rider's chainsaw.
"I get the gist of things." Decade nodded as he parried the chainsaw, disarming Buffa once more. "Yes, there are Kamen Riders who are the scum of the Earth."
Buffa charged at Decade as soon as he was disarmed of his weapon.
"Why does that mean every Kamen Rider is responsible for your loss?"
"Form Ride: Zi-O II."
"Attack Ride: Precognition"
Decade kicked the purple Rider's abdomen and slammed him to a light post.
"The sins of the few are hardly the sins of everyone affiliated."
Decade ducked and dodged an attack from behind courtesy of the vines that Buffa had summoned.
"Form Ride: Flaming Tiger."
"I walk the path of the destroyer so they can save the world from me."
Decade stomped his foot and lit the ground on fire, incinerating all the summoned vines to ashes."
"Kamen Ride: Geats."
Decade's form changed from a green and orange form with a tiger and grasshopper theme to a white and red form with a fox theme.
"I will continue to drag my name into the mud, to walk the path of villainy so they can be heroes that people revere."
"Final Attack Ride: Ge-ge-geats."
Decade jumped as a red bike zoomed in on location and changed into a fox that jumped after him. He positioned himself to perform Kamen Rider Geats's rider kick as the fox from earlier burst into flames and encased his extended foot with fire.
The kick hit Buffa's chest, and the resulting explosion de-transformed him out of his bull-zombie suit as Decade, in Geats's form, landed behind the defeated purple Rider.
"If you can't even touch me while using a fraction of my power, using a fraction of the powers of a few Kamen Riders, what hope do you have of destroying us."
"I… Swear… I… Will… Des… Troy…"
Buffa fell unconscious, unable to finish his train of thought as the white and red Kamen Rider changed into the pink Kamen Rider.
"Tsukasa-kun!"
The pink Kamen Rider – Tsukasa – looked behind him as he de-transformed out of his pink armor wearing a pink suit and snapped a picture of his surroundings.
"What now, Narutaki?!" Tsukasa called out.
One of these days, Decade, you will get your just dues!"
Narutaki, the man in a bowler hat that was goading Buffa earlier, sneered before he walked to a distorted space and disappeared.
"He was here?" The woman questioned.
"The whole time." Tsukasa nodded.
"Where were you?"
"Just roaming around, Natsumikan, you know that."
"The last time you roamed around, you intervened with Zi-O's story." Natsumikan raised an eyebrow.
"You know Zi-O's powerset would have forced us into the story whether we liked it or not," Tsukasa pointed out as he took out a pink thing that looked like a watch. "It was better that only Kaito and me were there because we kept our agencies and memories as we went through the story."
"We could have helped, you know." Natsumikan pointed out.
"And you would have probably been a great asset, convinced Zi-O not to go on a suicide mission and found another way."
"Wait…"
"We're similar in that regard, too similar for my tastes."
"Oh, Tsukasa-kun."
"No matter, it seemed like I needed to put a bull in place." Tsukasa pointed towards the fallen rider.
"Did you –"
"No, he's just unconscious."
"Oh, Yusuke told me who the Kamen Riders of this world were, at least the four prominent ones."
"I already know their names."
"You know their Rider designations, but not their human names."
"That's fair."
"Geats is Ukiyo Ace, Tycoon is Sakurai Keiwa, Na-go is Kurama Neon, and Buffa is Michinaga Azuma."
"Huh, it's interesting that another Sakurai is a Kamen Rider," Tsukasa hummed as he looked over Natsumikan's shoulders and read through the text that she received from Yusuke. "They have the same Kanji too. We should tell Kaito or Zeronus."
"That's weird, the words 'is' and 'was' keep interchanging."
"Geats and Tycoon are presumed dead," Tsukasa revealed. "Killed by the Bull over there." He pointed at his fallen enemy.
"If it's interchanging…"
"There is a high chance that they'd either be revived sooner than we thought or were never dead in the first place." Tsukasa nodded.
"Should you have interfered in this world's story, Tsukasa-kun?"
"There is a high probability that Buffa might just forget our entire encounter, we're probably safe."
"if you say so."