A/N: HI READER

We're back for some more Decade boyos. Our first destination, the World of Build, more specifically my RWBY/Kamen Rider story Build a Legend. I would recommend reading the first volume of that before this because this will contain spoilers, this also happens before vol 2 and after the Movie War.

So now let's get this going.

KAME RIDE! WRITER!

Destination 2/World of Build 1: The Best Match

Shiro and Kari looked at the portrait in front of them with confusion. Yes they knew of the Full Bottles, but these other objects were what spun their minds.

"So, what exactly is RWBY? In fact, what's with this Realm stuff?" Shiro asked.

Kaijin cracked his knuckles and sighed. "I knew these kinda questions would come. You see this Rider Universe is a special one, the way Rider Worlds are able to stay stable are if they are combined with a Realm. Realms are different types of tails, this one is the story of four girls trying to protect their world from dark forces."

"So what's our game plan?" Kari spoke up. "Find this guy, copy his powers and leave?"

"Not that simple!" Kaijin crossed his arms like an X. "Rider powers cannot simply be copied they must be earned. You must feel the same drive and passion as the Rider that has those powers." He explained. "Now whaddya think of your new clothes?"

The two were confused at what he was saying, until they noticed their attire was completely different. They now had some sort of school uniform on that consisted of a black blazer and trousers with a white shirt and red tie, although Kari had a checked skirt and tights.

"What-when-and-how?!" Shiro asked quickly with wide eyes.

"It's a sort of special mechanism that allows you to blend in with this world." Kaijin explained as he walked over to the kitchen. "Do you want money or packed lunch today?"

"Why?" Kari asked.

"Because you two are headed for Beacon Academy!" He laughed at his stupid lunch time joke.

As night drew close with Shiro and Kari getting ready for their mission, no one seemed to pay mind to the silvery veil appearing in an alleyway of Vale's streets.

Dark Decade stepped out with a hazy sigh as he looked outside the alley into the city.

"What a strange world…" He looked up towards the shattered moon. "But not a problem none the less…"

He opened his Booker and reached for a blank card. "Now let's see what Rider belongs to this world…"

The card glowed and revealed a Rider helmet of a mix of red and blue. "I see you're eager my friend. Well, let's not hold back any longer…"

SUMMON RIDE! ANTI-BUILD!

As Dark Decade shut his Driver, dark energy began to form in front of him, and soon enough it became a humanoid shape.

The person looked completely like Kamen Rider Build, except the overall colour was a tinge darker and had an evil aura around him. He bowed to one knee to his master.

"Arise my faithful warrior…" Dark Decade instructed.

The new Rider grunted as he stood, cracking some of his bones satisfyingly.

"Master Dark Decade, a pleasure to be summoned. Anti-Baron at your service." He slid two fingers across his rabbit visor. "I take it I'm gonna get my hands dirty?"

"Right you are…" Dark Decade answered. "Find your goodie two shoes version and eliminate him. Oh and if you see a certain pink Rider, kill him too…"

Dark Decade's hand glowed navy blue as he sent energy into Anti-Build.

"I've given you an upgrade, do not disappoint me…" He stepped into the shadows as his blue visors dimmed away.

"Ah it's great to be out and about." Anti-Build cracked his knuckles and chuckled evilly. "Let's bring some chaos."

"So this is Beacon." Shiro said as he and Kari stood in front of the castle like building. "I'm waiting to see Mickey Mouse or Tinkerbell appear from somewhere."

"Will you focus. Now which of these guys looks like a Kamen Rider to you?" Kari asked as she looked over all the students to try find this world's Rider. "They've gotta stand out right?"

"It could take a while, I mean this school is filled with maybe a thousand students." Shiro said as the two were about to enter the Academy, if not for suddenly having acing pains in their heads. "What the hell?"

It was then their eyes landed on someone specifically. He was a sixteen-year-old boy with brown hair and blue eyes, wearing a green and purple trench coat over the Beacon uniform as well as a pair of purple goggles.

The pain died down as they felt a strange feeling coming from that kid.

"Oh yeah, without a shadow of a doubt that's the guy we're looking for." Shiro grunted and rubbed his head. The bell rung and the two looked at each other. "Time for classes then."

Their first class of the day was with some man named Professor Port and some lesson called 'Grimm Studies'.

"Attention students!" Port announced as all the students took their seats. "It is brought to my attention that we have a pair of new students joining our school today. I am proud to introduce Shiro Kadoya and Kari Kaitou." He introduced as the two teens walked to the front of the classroom.

"Um….hi." Shiro waved.

"Now of you two could take a seat against…hmm, how about team RWBBY?" He pointed at a row in the middle where the goggle head kid sat with four other girls, a red-haired girl, a white-haired girl, a black-haired girl with a bow and a blonde-haired girl. "Make them feel at home team."

The two made their way to the free seats next to RWBBY as Port began the lesson.

"Psst, new kid." Shiro heard the boy of the team whisper to him. "Just a heads up, this'll be the longest hour of your life."

"What, why?" Shiro asked confused at the statement. The goggle head only counted three, two, one with his fingers as the Professor began one of his stories. This seemed to affect the class as a whole as the story was just SO damn boring. "Oh, that's why."

"Welcome to Beacon." The guy chuckled. "Name's Baron Aldwin. These are my friends Ruby, Weiss, Blake and Yang." He introduced the four girls.

"I'm Shiro, this is my best bud Kari. Kari?" He turned to said girl, who actually looked like she was enjoying the story. "Oh jeez."

So about a half hour later, the story had got so boring that Shiro had fallen asleep. Something that Port noticed.

"And in the end, I mounted that beast's head atop my wall! Mr Kadoya!" He yelled which sprung Shiro up. "Can you tell me the moral of the story?"

"Um….um…um….um…."

"I'll take that as a no." The Professor sighed as Shiro nodded. "Right then, come to the front of the class."

Shiro got up and made his way down the stairs. "Now if you're not that much of a listener, let us see if you're a fighter." He motioned to a crate with glowing red eyes. "Do you need to get changed?"

"Uh, no I'm good." Shiro looked at the crate as something inside growled. 'So this is one of those Grimm things Kaijin told us about. Well this is a good chance to get used to my armour a little bit.'

Shiro reached behind his back and pulled out his Neo-DecaDriver. This caught Baron's attention as Shiro placed it on his waist. He opened the Booker and took out his basic card.

"Okay, here we go. Henshin!" Shiro placed his card and shut the Driver.

KAMEN RIDE! DECADE!

Eighteen silhouettes appeared around Shiro and shifted through him as his armour was formed. His green visors flashed as he rolled his neck.

"Oh wow, sis look his armour's pink!" Ruby pointed at Shiro's Rider form.

"Actually, it's magenta." Kari said. "It's a common misconception but it gets very bothersome."

The cage rattled some more before the door to it burst opened. Running out of it was pitch black wolf like monster with bone armour and red eyes.

"Well Mr Kadoya, let's see if you can handle a simple Beowolf." Port said as Decade got into a fighting position. The Grimm roared and charged at Decade. It jumped and tried to claw the Rider who rolled out of the way.

The Grimm pounced at him and Decade braced as it tried to bite at his helmet. "Buzz off Fido!" Decade punched its stomach and then kicked it off.

Decade took of his Booker and made it into sword mode. The Grimm ran again and as it jumped Decade slashed across its stomach and then back. The Grimm then landed a scratch on the Rider's chest which made him stumble back.

ATTACK RIDE! SLASH!

Decade's sword glowed a bright magenta as he delivered multiple fast slashes. With one last slash he knocked the Beowolf into its cage.

"Oh yeah, who's boss? I'm boss!" Decade chuckled. The Beowolf growled before smoke entrapped its body as it grunted. "Um what this?"

"It's evolving!" Baron yelled from his seat as all the students, except RWBBY and Kari, sprung from their seats and ran.

With a howl, the smoke erupted off. The Beowolf looked more humanoid with its right arm bigger than its left with huge claws, it had more bone armour along its chest and its head had a wolf shaped helmet that covered its entire humanoid shaped head. The Evo Beowolf roared and swung its massive claw.

"Damn, looks like something Shocker would make." Decade remarked before the Evo Grimm ran and attempted to stab at the Rider.

But as the claws were to impact, a white snowflake symbol appeared before and stopped it in place, getting its claw stuck.

Decade looked up as all of team RWBBY came down with their weapons ready, Ruby had a scythe, Weiss had a rapier sword, Blake had short sword and a cleaver, and Yang had a pair of gauntlets.

"Well, certainly been a while since we saw something like that." Yang smirked and cracked her knuckles.

"Wasn't the last one at the Forever Fall Forest?" Weiss wondered.

"Oh that thing sucked…" Ruby grumbled.

"Oh boy, thanks a lot Port you just gave us a pain in the ass." Baron groaned as Port just chuckled nervously. "Well let's get it on!"

Baron pulled out a black Driver and slapped it on his waste. He then took out a pair of Full Bottles and gave them a quick shake.

RABBIT!

TANK!

BEST MATCH!

Baron gave a shrug with a smirk and spun the crank on the right side, making two half bodies appear in front and behind him.

ARE YOU READY?!

"Henshin!" The half bodies slammed onto him and hissed with steam.

FULL METAL MOONASSAULT! RABBITTANK! YEAH!

"Alright Weiss, set it free!" Ruby said as she cocked her sniper rifle function of Crescent Rose. Weiss flicked her fingers upwards as the Glyph turned black and sent the Evo Grimm flying into a wall.

Blake changed her sword to a gun and blasted it with bullets as the Evo Grimm managed to pull itself out of the wall.

"Ladybug!" Ruby ordered as she and Blake rushed over and circled around the Grimm and slashed at it multiple times. As they parted, Yang ran in and delivered it with dust powered punches that caused minor explosions.

The Grimm crashed into a desk, and as it pushed itself up it reached for a spike on its shoulder and ripped it out to reveal a bone sword.

Build and Decade charged at the Evo Grimm. The half and half Rider used his spring to jump a bit higher to try punch the Grimm's head, but the monster swung its bone sword across his chest as Decade rushed in and stabbed its shoulder.

The Grimm growled and went to swing its giant claw, if not for Build to jump in and block it with his Tank Arm. Build threw the claw away and did a spin kick, with the tread on his right foot spinning as it dragged across the Grimm's torso.

Weiss created four Glyphs that then fired white energy blasts that pinned its arms and legs spread.

READY?! GO!

FINAL ATTACK RIDE!

Build had just spun the crank again as Decade inserted his Final Attack card. A row of cards in front of Decade as Build's right foot was covered in red and blue energy.

VOLTECH FINISH!

D-D-D-DECADE!

Decade charged in with his sword as he passed through each card while Build jumped up and stretched his right leg forward.

"Tank Treader Kick!" Build's kick landed as the tank tread skidded past the Grimm. Decade then passed through the last card and slashed across the monster's chest. The monster roared once more and exploded, leaving some black gas which quickly dispersed.

"Aw dammit, I could've gotten a Bottle from that." Build sighed as he cancelled his transformation, with Decade following suit.

Before Shiro could even sigh, Ruby rushed over to him with a bombardment of questions.

"What kinda armour is that?! Do you have any others?! Is your book a sword?! What else can it be?! CAN I TRY IT ON?!"

"Personal space please?" He nervously said as Ruby's eyes seemed to turn to stars.

"Come on sis, give the guy some space." Yang said as she tugged her hood. "Gotta say Pinky, not bad for a transfer student. Where you from?"

"Oh…well that's a pretty long story." He scratched his hair. "Hey wait a minute, why did you do anything?!" He turned and shouted at Kari.

"Meh." Was her only answer.

"What do you want to do today Stalk?"

"The same thing we do every day Shroud, try to take over the world!"

"That was dumb." Shroud said as Stalk just skipped over to a crate. "But seriously, with Torchwick stuck in prison we gotta pick up his slacks. Even with these idiotic White Fangs and Droids we can't get any work done."

"Well it's not exactly easy to think of a crazy evil plan. Ooh, maybe we can use the death ray?"

"I have a better idea," The two steam villains sprung up as they heard that familiar annoying voice. They glanced at the warehouse's door to see the red and blue glowing visors of Kamen Rider Build. "Hello there Blood Stalk, Night Rogue."

The two pulled out their Transteam Guns and aimed at him.

"Whoa-whoa calm heads my friends." Anti-Build chuckled as they kept their guns trained. "I'm here to have a little talk."

"Why would we talk without enemy?" Shroud questioned with a glare.

"Tsk-tsk-tsk. Oh I am not the Baron you know and hate, I'm a much better one." Anti-Build eased the tensions."

"Hmm," Stalk looked at his free hand to see if it glowed or not, no matter how hard he tried. "You're right, you aren't our Baron."

"See, I told you so." Anti-Build walked over to the two. "Now how about we discuss a little alliance?"

"Why would we ally ourselves with you?" Shroud still had her gun out even when Stalk lowered his. "You just waltzed on in here like it was nothing and think you can boss us around."

"Shut up Shroud, let the guy talk." Stalk silenced her. "How can you help us?"

"You need to use those Bottles to turn people into SMASH with Nebula Gas." Anti-Build made the same black gas from the Grimm appear around his hand. "I can do it with a simple touch."

The Anti-Rider then noticed two White Fang members walk past and decided to show off.

"Let me show you." He used the spring on his leg to bounce over to the two White Fang members and touched them both on the chest, engulfing both in the black smoke.

"APE!"

"SHINEY!"

"BIRDIE!"

"BANG-BANG!"

The smoke dispersed to show the two had turned into SMASH. The first looked like a humanoid gorilla with diamonds on its back, head, and arms. The second was a humanoid bird with a pair of gatling guns on it arms, and cybernetics on its body.

"Tada~~~~." Anti-Build chuckled as the two SMASH roared.

So after the attack in class, team RWBBY took Shiro and Kari into Vale for a look around. And during all that, Baron had a lot of questions for Shiro.

"Lemme guess, you're not from around here either?" Baron whispered as the two boys trailed back a bit.

"Is it that obvious?" Shiro sighed but then realised something. "Wait, 'either'? Are you-?"

"Yep, got sent here from some other place. Just woke up in a forest."

"So you're trapped here? If you want, Kari and I could probably get you back to your world." Shiro offered, but Baron shook his head with a smile.

"There's no point, I got nothing back there, but I got everything here. Ya see I've got amnesia and don't remember much, but I have memoires here."

"But what about your family back on earth?" That made Baron loose his smile. "Oh, I…I'm sorry."

"Don't worry about it." Baron wiped away a tear. "But anyway, I gotta ask about that armour of yours. How does it work?"

"I don't exactly know myself, my dad gave it to me as a birthday present. He was the Decade before me. Kari's got one too," On cue Kari showed off her Neo-DienDriver.

"Huh, looks familiar. Well that is if you replace the blue with green." Baron tilted his head as he looked at the gun.

"So wait, you could've helped during the fight, but you didn't. Why?" Blake questioned.

"Meh, you guys had it handled." Kari shrugged with a smirk. "Now what is there to see in this city? I need tourist attractions!"

"Well there's the CTT. We could take you there." Blake offered. "There's also a shopping mall near there too."

"Good enough."

"You boys coming?" Yang asked. Shiro was about to answer but Baron slung an arm around him to answer.

"Nah, I'll show him around some other places. Meet you all at the Air Docks at 5:00?" He didn't wait for an answer and just dragged Shiro away.

"How do you cope with him?" Kari asked which made Yang roll her eyes with a smile.

"Well it's not easy."

Baron had taken Shiro down to the local arcade for some 'bro dude time' or some shit. The two were currently playing some arcade games right next to each other.

"So you're travelling through different worlds?"

"Yep."

"And you have to stop this evil guy from killing me?"

"Yep."

"But by doing that you need to make a copy of my powers?"

"Yep."

"Holly hell that is convoluted." Baron chuckled as a 'GAME OVER' appeared on his screen. "Aw damn."

"Yep." Shiro completed his level and got some prize tickets. "So what exactly is this place, Remnant I mean?"

"It's a strange world." Baron answered as the two went to leave. "This place has basically been at war with the Grimm for….maybe hundreds of years. I only came here about a month or two ago."

"Do you ever….I dunno…ever have second thoughts of all this?" Shiro asked as he dumped his tickets into a nearby bin.

"Sometimes, but I know I never really had a choice in the end." Baron reached into his shirt and pulled out a locket.

Shiro was about to comfort the other Rider, but he heard the sound of wings beating as well as a whirring sound.

A bird like shriek filled the air as the two Riders turned around to see some sorta monstrosity flying in the air. The monster aimed both its arms, showing them to be gatling guns, and fired an onslaught of bullets.

"Run!" Shiro shouted as he and Baron made tracks from the barrage. The attack stopped as the monster landed in front of the two.

"A SMASH." Baron recognised.

'Oh yeah, I remember hearing about these things. Gotta beat 'em really hard to free the poor sucker trapped in it.' Shiro thought back to what Sento had told him. "Baron, you alright?"

"Y-yeah but…this thing looks familiar." Baron then had a face of horror as if remembering something VERY bad.

"What?"

"It looks like HawkGatling….one of my Best Matches!"

The SMASH shrieked and spread its wings as it flew to attack the two. They both rolled out of the way and attached their Drivers.

KAMEN RIDE!

RABBIT!

TANK!

BEST MATCH!

Baron and Shiro stood up readied themselves.

ARE YOU READY?!

"Henshin!"

DECADE!

FULL METAL MOONASSAULT! RABBITTANK! YEAH!

The two now stood in their armours as the SMASH went to strike with its talons. Decade pulled out his Booker and turned it to gun mode as Build took out his Drill Crusher also in gun mode.

They both opened fire with the blasts bleeding sparks off the SMASH. As it crashed, Build threw turned his weapon to sword mode and rushed to attack. The drill spun as he managed to cut into the cybernetics on its chest.

ATTACK RIDE! BLAST!

The barrel of the Ride Booker glowed a hazy magenta and let loose his own barrage. The lasers managed to push back the SMASH into a wall.

"I hope the girls are alright, cause if one of these things are after us then one's probably after them." Build said with a worried tone.

"Oh no, Kari!"

"What's wrong, she'll be fine won't she?"

"Trust me, she can talk a big game but rarely backs it up." Decade explained, just as the SMASH freed itself from the wall and ran to attack them again.

[Meanwhile, with the girls]

"You really like blue don't you?" Weiss shook her head as they finally left the mall. Everyone else had maybe a few things while Kari had left with a full-on bag of shit.

"Yes, I do. It's my colour." She defended. 'Not like it's my money I'm spending. Kaijin did say this Lien stuff was given to us as soon as we got here.'

"Well how's about we meet up with the boys then, they're probably done being boys by now." Yang joked.

As they were about to leave, the five heard shrieks and yells of panic. They turned a corner and saw people running away from a SMASH. The GorillaMond SMASH beat its chest and roared.

"Is that a SMASH?" Ruby gasped as she looked at the creature. "Why does it look like one of Baron's Best Matches?"

"Whatever it is we need to take it down." Blake said as she unsheathed her Gambol Shroud.

"*Sigh* I just wanted a day out." Kari complained as she dropped her bags and pulled out her Neo-DienDriver.

KAMEN RIDE!

She spun the Driver on her finger and aimed at the sky.

"Henshin!"

DIEND!

Three holograms shifted around her before coming together to create the Diend armour.

"Alright monkey boy, you don't ruin a girl's day out!" Diend shouted as she aimed at the SMASH and fired blue lasers. The lasers seemed to bounce off the SMASH's diamond shelled arms.

It roared and tore up a piece of the ground to then throw at the girls. Yang jumped in front and punched the piece of ground into little bits. Weiss created a time Glyph that accelerated her speed before she dashed forward to deliver quick slashes and stabs before Ruby dashed over to slash with Crescent Rose.

She then cocked the sniper function and blasted a bullet into its head.

ATTACK RIDE! BLAST!

Diend aimed her Driver as holographic copies of her gun appeared around it. She pulled the trigger as all versions of that DienDriver fired lasers.

The SMASH roared and fired diamond spikes from its body to in all directions. Some impacted on Diend and bled sparks off her armour.

Blake turned her weapon to whip mode and flung it to wrap around the SMASH's leg. She struggled to keep it in place as Yang charged in and struck with her Dust powered punches, one last punch sent to monster into a wall.

Yang shook her hand slightly as some smoke came off it. "Damn that's got some tough skin on it."

Diend pulled out one of the diamond shards stuck in her suit as the five girls regrouped.

"Alright team, let's finish this thing off!" Ruby said as they all nodded and charged again.

ATTACK RIDE! RIDER PUNCH!

Decade's right hand glowed a light magenta as he rushed to the SMASH and delivered a punch to its stomach.

PHOENIX!

READY? GO!

Build's Drill Crusher blazed with fire as he used the spring on his leg to bounce over and prepared to attack.

VOLTECH ATTACK!

Build stabbed the Drill Crusher into the SMASH's chest as the fire spiralled into a full-on tornado that he used to slash twice.

FINAL ATTACK RIDE!

Decade turned his Booker to gun mode and aimed at the SMASH as a row of cards appeared in front of him.

D-D-D-DEADE!

Decade pulled the trigger, firing a magenta blast that passed through each card and blew up the SMASH.

As the fires dispersed, it showed a member of the White Fang who recovered before having a panicked look as his body disappeared.

"What's happening to him?!" Decade demanded as Build let out a gasp. The White Fang member glowed before he was gone.

"H-h-h-his Hazard Level must have been too high, his body couldn't take it." Build said in a shaken up voice.

The two Riders heard a slow clap come from all around them before it zeroed in on someone walking to them. And who it was seemed to shock both Riders.

"He…..looks like me?" Build questioned.

"Oh I don't just look like you, I am you." Anti-Build chuckled as he stopped clapping. "Well, that was a disappointing experiment. I'd have hoped that one of my special SMASH could last a bit longer."

"You turned him into that?!" Build yelled at his counterpart, who only laughed in return.

"Why yes I did. I overloaded his body with Nebula Gas to prove my little theory; this world's people truly are pathetic. Now thanks to this power I can now spread hatred and chaos! HA-HA-HA-HA-HA!" The two Riders growled as he continued to laugh.

A/N: And there we go, an introduction to the main monsters of this story, the Anti-Riders. So with this being the first half of the Build a Legend arc we all know what'll happen next time.

Also for anyone wondering why I didn't start with Kuuga like every other fic, well that's because I don't have a Kuuga story yet to travel to, as well as I'm not having anyone from the worlds join Shiro and Kari on their journey.

But now for reviews!

DragonKnight SR: Why yes, there shall be.

RealEWF: Oh yeah, he's inevitable.

lenz012696: Yes it does.

Well anyway I'll see you guys next time.

BYE, BYE.