Disclaimer: I do not own any of the material appearing in this story.

BGM: Interlude (Super Mario Galaxy)

The front doors opened and then everyone walked in, ready for whatever would be thrown at them… but to their surprise, it was quiet. Too quiet.

"Be on your guard." Saizo warned. "You'll never know what might happen in this darkness."

"Agreed." Ryoma said. "Split up, maybe we can find something of interest, but like Saizo said, be on your guard." He said as they nodded and went toward the different rooms and different areas of the castle, even the basement, but there was no luck as they regrouped.

"Anything?" Xander asked.

"Nothing but empty rooms." Hinoka said.

"Not to mention some rooms are littered with party decorations on the ground." Subaki said.

"Oh, I know what we should do once this is over!" Elise said. "We should set up a few tables for a huge birthday party!"

"Just no animatronics, please." Luigi requested.

"Still haven't gotten over that one game, Five Days of Charlie's?" Mario asked.

"Nope." Luigi shivered.

"What are animatronics?" Hana asked.

"They're robots used for children parties, sometimes used at pizza places." Mario explained.

"…Wonder if you could give them weapons to spice things up a little?" Peri wondered. "That'd be heaven for me!"

"Hell for the rest of us." Inigo shuddered.

"Could I see one of these anima-thingys after this?" Elise asked.

"Judging from how Luigi is acting from these things, I'd advise that we don't." Xander said.

"Can we get back to the topic at hand?!" Weiss suggested as they nodded and went up the stairs as they proceeded to look around, but nothing was of interest.

"Does anyone smell cake?" Sumia wondered… and then there was silence. "Where's Gaius?"

"On a date with Reflet." Cynthia said. "I asked him if he wanted to come with us after that explosion, but he said 'No thank you, as much as I want to, I'm spending some alone time with my wife. And besides, I'm a thief and last I checked, they keep low profiles'." She recited from memory. "I told him he was a party pooper."

"Aww…" Ruby pouted.

Kagero emerged from the kitchen. "Seems like someone was baking cake a few hours ago. I assume it was the Koopa Troop, but I've never heard of them baking cake."

"Maybe they bake cake behind Bowser's back?" Kamui wondered.

"Hmm, perhaps…" Kagero mused.

"Or maybe they let Peach walk around the castle but wouldn't let her leave." Robin suggested.

"About that." Tiki piped up. "We were looking for intel on where the next Star Spirit was located and had Twink help you out. We just so conveniently ran into a fat Shy Guy named Gourmet Guy and, after baking a cake, he told us where the next Star Spirit was."

"Huh, so that's where he took off to." Silas mused as they walked further in the castle and into the hallway.

"This feels like déjà vu." Yang said.

"Yeah, but this time, we're well prepared." Blake said.

"We're almost there." Mario said as they hurried along, and as they got closer…

End BGM

"Well well well, look who decided to show up!" A voice exclaimed, as they looked at Bowser who was waiting for them, along with Roman, Neo, Kammy, Kamek and Peach who was tied up.

BGM: Angry Bowser (Paper Mario)

"Kamek too?!" Ruby exclaimed.

"That's right, I'm back! And… wow… that's quite an army you've got." Kamek said.

"No matter on that, I don't care how big your army is, or if you got lobster head and dark and sinister too! I will reign supreme on all of you!"

"I'll never understand why people think of me like that." Xander said.

"Now that we're all here… let's finish this, shall we?" Roman asked as Neo took out her umbrella with a smirk.

"Everyone, split up!" Robin ordered as they all jumped away. RWBY, Mario, Luigi, Nyx, Bow, Lakilester, Kamui, Ryoma and Xander took on Bowser; the Tome and Bow users dealt with Kamek and Kammy, the lance wielders dealt with Neo; and the others took on Roman.

"Bwahahaha! Can you really defeat me?" Bowser chuckled as he breathed fire on them, but they quickly avoided the attack, Ryoma and Xander both ran and slashed him repeatedly before jumping back. "Grrr!" He growled as he jumped up in the air to ground pound them, but Nyx shot him in mid-air to knock him back.

"Alright, let's try this!" He said, pulling out the Star Rod and glowed brightly as Kamui ran over and slashed him, but she didn't leave a dent. "Bwahahaha! I'm invincible! You can't touch me!" He said, back handing Kamui to knock her back, but she recovered.

"Cover me." Mario requested.

"You got it, bro!" Luigi gave him a thumbs up as Ruby quickly ran toward Bowser and did a Ruby Tornado, similar to Sonic, as Bowser tried to attack her, but he was sucked into the tornado, which luckily for him, didn't affect him.

"Come on, what did I just tell you? I thought you were smarter than that." He said.

"Oh, I know!" Ruby said. "I'm just distracting you." She smiled and jumped back as he was then encased in ice by Weiss… and then Mario was ready.

"Star Spirits… help us out here!" He requested as the Star Spirits appeared and floated above Bowser who broke out of the ice.

"Didn't even phase me!" He said… and then the Star Beam hit him. "Bah! …What was that?" He wondered as Kamui tried again, and this time she was successful. "ARGH! …Wait, you hit me?! How is that possible?!"

"Gotcha!" Ruby grinned as Yang jumped in and punched him hard where the Mario Bros hammered him, and then he was pelted by Spinies from Lakilester and then Bow slapped him hard with her fan.

"Grr… I don't know what you just did, but I'm not liking it!" He said as he got in his shell and rolled toward them, Kamui went into her dragon form and shot water at him to knock him back as he got back up, where Ryoma slashed through him. "AAARGH!" He yelled as he quickly used the Star Rod to make him invulnerable again. "BWAHAHAHA!" He roared and then breathed fire at them, forcing them to dodge… and then Mario used Star Beam again, knocking it right out of him… and then Xander glowed.

"You're right where I want you!" He said and slashed through him, as Bowser roared in agony and jumped back.

"…Alright, you want to play hard ball?!" He asked. "I'll give you hard ball!" He said as he jumped up to grab Peach.

"Ack!"

It was then that he whistled, signaling his Koopa Clown Car to scoop him and Peach up. "You want to end this? Then meet me outside on the roof!" He said and took off.

End BGM

"See you losers on the other side!" Roman said, throwing a flashbang down, blinding them all… and when the light disappeared, they were gone.

"To the roof!" Ryoma said as they took off to the roof, ready to end this once and for all, as they eventually saw an arena for all of them as they jumped in.

"Heh, you were sure dumb enough to come here!" Bowser taunted. "Now this is where we seal the deal. Kammy! Kamek!"

"Right!" They both nodded and proceeded to charge up.

"This is a special arena designed for us to kick your butts!" Bowser said. "You wanna know why it's special?" He asked… and right on cue, Kammy and Kamek both fired beams at Bowser, making him bigger.

BGM: King of the Koopas (Paper Mario)

"IT'S SPECIAL BECAUSE IT POWERS US UP! BWAHAHAHAHA!" He roared, and while Roman and Neo didn't get bigger, they did get a nice power boost.

"Eeep!" Sakura paled.

"Oh, like that should scare us!" Hana said.

"Please, like that'll be any different." Hinoka said.

"Yeah, why should this be different?" Niles wondered.

"Oh, why don't you find out?" He chuckled as they proceeded to fight again with the same tactics as before, though Kamek and Kammy decided to stay out of it this time. However, when Bowser unleashed the Star Rod to start glowing, Roman and Neo glowed too.

"That's nothing." Mario said, unleashing Star Beam on Bowser… but unlike last time, it didn't even get rid of that.

"Uh oh! What's this? It seems like you can't even use that now! BWAHAHAHA!" He laughed, and as Robin used Arc Fire on Roman, it didn't leave a scratch.

"Ohohoho! So this is what it feels like to be invincible!" Roman laughed while Peri kept stabbing Neo multiple times.

"Come on! Why can't I stab you?!"

"She's invincible, Peri! She can't be hurt nor stabbed!" Inigo said.

"What?! That's not fair!" Peri complained as Neo seemingly let out a small chuckle.

"Oh no… what do we do now?!" Ruby asked.

"We find a way. We always do!" Yang said.

With Peach…

"This is bad… I gotta help them!" Peach said, as she got out of her ropes as she went forward… but Kamek and Kammy got in the way.

"And where do you think you're going, princess?" Kamek asked, aiming his rod at him. "You're not going anywhere!"

Peach spotted a rock on the ground as she knelt down and picked it up. "Out of my way!"

"Oh, and what's a rock going to do in this situation?" Kammy asked. "Let's show her that a measly rock won't do her any good!"

"Right behind you, ehehehehe!"

"HIYAAAAAAAAAAAAAAAH!" A voice yelled, as Twink suddenly tackled the two from behind and came to Peach's aid. "Don't you dare!"

"…That little brat again?" Kamek asked.

"Bah, like he can do anything!"

"I'll help you!" Twink said as he got in front of Peach. "I'm… I'm not scared!"

"Bahaha! Get a load of THIS!" Kamek yelled, shooting a fireball at him while Kammy sent a block on him, hurting Twink.

"Gah!" Twink winced and then attempted to attack the two of them, but to no avail.

"That tickled!" Kammy laughed.

"Ehehehe! This is gonna be quick!"

I gotta do something… Peach thought and closed her eyes, hoping Twink can outdo these two as Twink powered up a little.

"Yah!" Twink yelled, hitting Kamek and Kammy.

"Okay, that hurt a little, but that still wasn't enough!" Kamek taunted as they did the same thing.

"Nngh…!" Twink winced and then he felt powered up more by Peach as he attacked them again… and after a few more hits and a few more wishes from Peach…

"Take THIS!" Kamek yelled, unleashing a massive fireball at Twink, resulting in a small explosion… but as the smoke settled, Twink was unharmed. "WHAT?!"

"Don't mess with me!" Twink said.

"Impossible! He should've been hurt!" Kammy said, firing a block at him to squish him… but Twink raised his arms up and grabbed it. "…Uh oh…"

"YAAAAAH!" He yelled, throwing it right at Kammy as it broke… but it did knock her out.

"What in blazes just happened?!" Kamek asked… and then he got kicked in the face by Twink to knock him unconscious.

"How did that happen…?" Peach wondered.

"Simple! Your wishes were pure in heart and you wished for me to have strength to finish the fight! Now I have an idea!" Twink said and whispered in Peach's ear as her eyes widened and nodded as she closed her eyes, clasping her hands together.

"Mario!" Twink flew over to them who were struggling against the trio. "Use the Star Beam!"

"I can't! It can't hurt him!"

"Trust me on this!"

"…Alright." Mario nodded as he used Star Beam again… but it suddenly turned pink thanks to Peach's help and it transformed into the Peach Beam as it went between the three and unleashed it on them, proceeding to get rid of their invulnerability.

"Huh…? Why do I feel funny?" Bowser wondered and then Mario hammered him on the foot. "YOOOOW! …How am I hurt?!" He asked as Roman and Neo also got hurt from the attacks.

End BGM

"No way… that shouldn't be happening!" Roman exclaimed as Tiki transformed into her dragon form and flew over to Peach.

"Wanna help fight?"

"Sure!"

"Then hop on!" She smiled as Peach hopped on Tiki as they joined the gang… and then Elise and Sakura healed them all up.

"Alright, they're weak! Now let's end this once and for all!" Ryoma said.

"YEAH!"

BGM: Twilight of the Gods (Fire Emblem Echoes: Shadows of Valentia)

"Grrr! I won't let you win!" Bowser said, attempting to claw Hana and Subaki, but they jumped back as they both slashed him a few times and then Mario and Luigi jumped up and hammered him on the head to knock him back a foot.

Roman aimed his cane at Peach. "Take THIS!" He yelled, firing it at her but Tiki avoided the attack as she flew up and breathed fire at him, forcing him to roll out of the way… but Peach had jumped off of her and kicked him in the head before Tiki retrieved her.

Neo blocked every attack from Peri as she whacked her a few times with her umbrella and went in for the kill, but Peri blocked it with her lance and then retaliated by stabbing her a few times and then kicked her away where Inigo came in and slashed her. "Thanks Laslow!"

"Anytime." Inigo smiled as Neo glared hard at them and ran over to the two.

Camilla, Severa and Beruka went over to him and attacked Bowser as he attempted to breathe fire at them but Kamui had transformed and shot water at him to counter the flames until the fire died down. Bowser got in his shell and rolled toward them Kamui, but Chrom got in the way and slashed downward, knocking Bowser back.

"Alright…!" Bowser growled as he used his Star Rod and fired a lightning bolt at Niles who aimed a bow at him.

"Mmph!" Niles winced. "That the best you got?" He asked, firing a few arrows as Bowser ran toward the gang and breathed fire again, but they had jumped back as Owain pulled his sword back… and then glowed.

"ELDRITCH SMACKDOWN!" He yelled, slashing right through him.

"ARGH!" Bowser roared before using the Star Rod again to heal him and the others back up… and then Henry used Elfire on Roman to knock him down and he tried to get back up… only to get a thrown frying pan to the face from Peach, knocking him down for the count.

"Nice throw!" Henry said, high fiving Peach. "…Aww, there's no bloody nose!" He said, taking a close look at him as Neo glared hard at Henry and went to attack him, and it was at this time that Peri glowed.

"I'm feeling stabby!" She said, and quickly stabbed Neo several times to knock her down and then Inigo went over and dealt the finishing blow on her to defeat her. "I'm gonna kill her!"

"No, let us finish the fight with Bowser."

"But… oh, alright." Peri sighed as they regrouped as Bowser did land a few hits on them, but to his dismay, Lissa, Sakura and Elise were patching them right back up as he breathed fire at the healers, but Effie came in and blocked with her shield and then Arthur slashed him with his axe… and then he glowed.

"Beware my fists of justice!" He said, slashing him hard.

"ARGH! You didn't even use your fists!" Bowser pointed out.

"Ah, but I used my fists to hold this lovely axe, so I did indeed use them!" Arthur countered.

"…You little!" Bowser attempted to claw him, but he jumped back in time and then Effie attacked him along with Saizo and Kagero as he jumped up and ground pounded them, and while he didn't hit any of them, the shockwave was enough to knock them on the ground… and then he used the Star Rod again to heal himself up and make himself invulnerable again… to which Mario countered with the Peach Beam, and then was attacked by Hinoka and her retainers, and then Lyn attacked him a few times before jumping back before she could be hurt by Bowser's claws.

Frederick pulled back and glowed. "Pick a god and pray!" He said and then brutally attacked Bowser where everyone went in on him and attacked while the healers healed them up if necessary.

"Alright, let's finish him off!" Palla said. "You guys ready?"

"Oh yeah!" Est nodded with excitement.

"Ready!" Catria grinned as the trio flew up in the air and prepared their signature attack, the Triangle Attack as they came down on Bowser and slashed through him at the same time.

"AAAAAAAAARGH!" Bowser roared… but to their surprise, he was still standing. "Argh… that the best you got…?"

"That wasn't enough?!" Est asked as they kept attacking Bowser… and then he healed himself back up with the Star Rod.

"…Alright, THAT'S IT!" Takumi said, aiming his bow at the Star Rod as he had unleashed lightning on the Mario Bros… and then fired an arrow to knock it out of his hands.

"Wha… No!" He exclaimed as he tried to grab it, but Twink picked it up.

"No you don't!"

"Come on, you guys! Let's do this!" Ruby said as RWBY went to attack him… when they suddenly glowed. "Grrr… you made me angry!"

"I'll freeze you right up!" Weiss declared.

"This is where it ends." Blake said.

"You're going out with a Yang!" Yang exclaimed, and then Ruby slashed through him, Weiss unleashed a flurry of ice attacks, Blake had circled around him with Gambol Shroud to trap him… and then Yang came in and punched him right in the head hard enough to knock him on his shell.

"Whoa! I didn't know they were capable of criticals!" Elise said.

"These girls continue to amaze me." Kamui smiled.

"Nnngh… argh…!" Bowser groaned as he shrunk back down to normal size… but he got up again and roared angrily at them, but as they were getting ready for another round, the whole place started to rumble. "…Huh…? What's going on?"

"Mmmph…" Kammy got back up and gasped. "Your nastiness! It seems as if that epic fight you had with them was hard on this arena. It's about to explode at any second!"

Bowser's eyes widened as he whistled again and got in his Koopa Clown Car while scooping up Roman and Neo. "Retreat! Now! I'm not gonna go out this way!" He said and glared at them. "I'll be back in the sequel! Just you wait!" He said and quickly took off fleeing with the others.

End BGM

"We need to move, now!" Ryoma said.

"Hang on, I got this!" Twink said, using the Star Rod to conjure up a protective shield around Peach's Castle and teleported them to the entrance while also getting RWBY's Stars in front of the castle for safety… and then Bowser's Castle exploded.

BGM: Star Spirits' Request (Paper Mario)

"Well, that seems to have done it." A voice said as they turned to see Eldstar and the others flying up to them.

"We couldn't have done it without you. Thank you all." Mamar said.

"Indeed, we are eternally grateful." Eldstar said. "We will be taking this back to Star Haven… and promptly setting up a barrier so that no one else will use this in the wrong hands. We don't want anyone stealing it again, not even a grumpy penguin dictator."

Do they know of that Dedede fellow? Ryoma thought.

"Fare thee well, everyone." Eldstar waved goodbye. "Maybe we will meet again at a different time, perhaps." He said as they all took off.

"…Peach… I…" Twink tried to say. "I'm… glad that I got to meet you and Tiki."

Peach smiled. "You too, Twink."

"I'll miss you…"

"We will too." Tiki said.

Twink went over and hugged the both of them. "See you later…" He said in sadness before he flew off as well, as they all waved goodbye to the Star Spirits and Twink. Twink took one last look at them before taking off, while Peach's Castle gently floated down back into the Kingdom.

End BGM

A few days later…

BGM: Mushroom Kingdom – Peach's Castle (Super Mario Odyssey)

"Are you kidding me, father?!" Lucina shouted as they were in Peach's castle. "You had this great big adventure to save the Mushroom Kingdom and you didn't invite me?! I would've helped out a fellow Smasher!"

Chrom sweatdropped. "Sorry… I didn't know where you were."

Lucina sighed. "It's alright… but still…" She looked at Owain, Inigo and Severa. "It's amazing that you went to a different time to help someone. Though, you could've told us this before."

Severa sweatdropped. "Sorry about that…"

"So, your name is actually Severa." Beruka said.

"Yeah, that's my actual name. Sorry if I-"

Beruka held her hand up. "No need to apologize." She said. "After all… Severa sounds better to me." She said, and in an instant, she flashed a small smile.

"…Are you smiling? You never do that!"

"Don't get used to it." Beruka said, dawning her usual frown… and then Camilla hugged Severa from behind.

"I don't care what your name is as long as you're my darling retainer~!" She smiled, squeezing her tight in a bear hug.

"Ack! Choking… not… breathing…!" Severa gasped for air… and then a flash was heard as Cordelia had taken a picture of this. "N-not… funny… mother!"

"Come on, it's cute!" She giggled.

"Hey, has anyone seen Luigi?" Ruby asked.

"He said he had to do something. Not sure what it is." Mario shrugged and then the doors from up the staircase opened.

"Thank you one and all for coming on this momentous occasion!" Peach smiled. "Thanks to those who risked their lives to rescue the Star Spirits, Bowser has been defeated once again and peace has returned to the kingdom!" She said as everyone cheered. "Mario, RWBY, Nyx, Kamui, Lyn, everyone from Hoshido, Ylisse and Nohr, Tiki, and Mario's allies who had joined them on their adventure… we thank you!"

Everyone cheered for them all as they could only smile and wave at them… though Saizo did his usual grumpy 'hmph', but nobody could tell that he did smirk through his mask.

"Geez, you go out on a date and you miss out on the fun." Gaius grumbled.

Reflet giggled. "But you wouldn't go out of your way to cancel the date, would you?"

"I might have." He said with a sly grin before chuckling. "Just kidding. Nothing is more important than you, Bubbles." He said. …Maybe except for candy.

"Thank yo-hey! What did I just say abou-oh, I give up." Reflet sighed with a chuckle.

"And now, for a celebration, I've cooked up a parade for all of us to watch!" She said. "It's just outside!" She smiled as they went out to go see the parade… and Luigi was up front with Affectio next to him.

"And a one and a two… come on, let's-a go!" Luigi called out and started to lead the parade as everyone cheered and clapped for the floats, as even the villains were on the action.

"Eh, we'll get 'em next time." Red said. "Right now, we celebrate! Let's pose!"

"Right!" Black said and then got ready to pose… and then some Bob-ombs, led by Bombette appeared and blew them up, causing them to scream and covering them in soot.

"Take that!" Bombette said… and then saw Tutankoopa running for his life with three Chain Chomps after him.

"WHY DID YOU BRING YOUR FRIENDS?!" He screamed as the Chain Chomps were barking.

"Hey! Give me back my body right this instant!" Tubba Blubba's heart ordered, chasing after Bootler and the fellow Boos who were carrying Tubba Blubba.

"Alright boys, hit it!" General Guy ordered as the Shy Guys brought out electric guitars and started jamming while General Guy played the drums… and then spotted RWBY. "This is a secret to everyone, you hear me? A SECRET TO EVERYONE!"

"…How is it supposed to be a secret when the whole kingdom knows?" Blake wondered.

"He's not very bright." Weiss said and then spotted Lava Piranha… though he was made out of cardboard.

"…That's the guy that you turned into a shish-kebob?" Hinoka asked.

"Y-yeah…" Sakura nodded.

Hinoka whistled. "Nice. I wish I was there to see that." She said and then Huff n' Puff floated on by.

"…Ooooh!" Effie drooled over him. "Cotton candy!" She said and then started to chase him.

"Whoa! WHOA! I'm not food! HEEEELP!" He yelled, flying away as Effie chased him, unaware that Gourmet Guy was also in hot pursuit.

"Dibs on his right arm!" Gourmet Guy exclaimed... and then three Crystal Kings showed up.

"…Wait a minute!" Crystal King said and then screamed at the two, revealing to be Duplighosts. "Aha! I knew it! You dare make a mockery out of the Crystal Ki-" The Crystal Bits arrived and took off with the Crystal King. "Hey, what are you doing?! Unhand me, you fools! I'm the original here!"

"Hiyah!" Jr. Troopa dodged attacks from both Kamek and Kammy and fired magic at the duo.

"Pesky little guy, aren't you?" Kamek asked as they kept firing magic… and right when Bowser floated in… they fired magic right on Bowser by accident.

"…Uh oh." Kammy said.

"Exit, stage right!" Jr. Troopa said and took off… but Bowser was glaring at the two Magikoopas.

"You're not angry?" Kamek asked.

"…I'm counting to ten right now… you better run. I'm already at five!"

"Meep!" Kammy exclaimed as they took off… and Bowser chased after them with Roman and Neo right behind him.

End BGM

As soon as the parade was over, it was night and they all looked to the sky to see fireworks exploding in the sky, and they knew one thing.

Peace has returned to the Mushroom Kingdom… but as everyone knew, that peace would be short lived when Bowser will come back with a new scheme.

Meanwhile, somewhere else…

"The time has almost come…" A voice said. "The door is weakening, and soon, I, Grodus, leader of the X-Nauts, will take that ancient treasure within it, and I will rule the world with the demon! GAAACK ACK ACK ACK ACK!"

And with that... Paper RWBY has officially drawn to a close. See ya next story!

Also, fun fact: I was originally gonna have Ruby break the fourth wall and say something about "Let's head back to the real world, shall we?" and then have a scene of a certain ghostly king set up a mansion filled adventure, but... as I was writing this chapter, I thought about the ending and I felt that going from paper to non-paper would've been extremely jarring, y'know? So I decided to change it to... well... the ending you see now!

Anyway, see you on the next RWBY story!