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

The girls and Kirby soon came to a stop as they looked at a huge rainbow in front of them. "That is so pretty!" Weiss exclaimed.

"I wonder…" Ruby said as she put her finger on the rainbow. "…Yup, it's definitely solid."

"Cool, so we can walk on it." Yang said as she proceeded to walk, only to slip and slide and fell on her back. "…Or not… ow…"

"Poyo poyo…" Kirby rubbed his head.

"Hey guys, look!" Blake pointed to a sign as they read it.

"Welcome to Rainbow Road, where you can ride on it to your heart's content! Strangely, the road is only slippery when you step on it. If you don't have a kart, then that's fine, you can get one out of this ? block for the vehicle of your choice! Have fun!

PS: If you're a certain pink puffball, then there's another ? block just above the other one.

PSS: Once you're done, hit the ? block again and the unselected vehicles will go back in the block."

"Rainbow Road, eh?" Ruby asked as the girls proceeded to hit the ? block, and all of the karts and bikes from all the Mario Kart races appeared as Kirby did a flip kick and all of the Stars from Kirby Air Ride appeared as well.

BGM: Argue For and Against (Touhou 10.5: Scarlet Weather Rhapsody)

"Hmm, what to choose…" Yang rubbed her chin in thought as they looked around the makeshift garage as Kirby pondered over the stars until he saw the Formula Star.

"Poyo!" Kirby got on it.

"Oooh, this looks nice!" Ruby chose the P-Wing.

"This one looks epic!" Yang chose the Flame Rider.

"Hmm, none of them seem to fit me…" Blake said, then saw the Mach Bike. "Well… that seems to work."

"Sports car, coming through!" Weiss said, as she chose the 300 SL Roadster as Yang hit the ? blocks as the unselected vehicles disappeared.

End BGM

World 7-3: Rainbow Road

The girls and Kirby drove onto Rainbow Road, revving up their engines.

Lakitu soon came down with a light post… thing on the end of a fishing pole. "You guys ready?" He asked as his question was answered by several engines revving up. "Take that as a yes, alright… one lap all the way to the finish line!"

The girls revved up the engines again, looking at each other with serious expressions and 'I'm going to wipe the floor with you!' look, while Kirby just looked forward with his happy-go-lucky smile. "Poyo!" He smiled.

"On your mark…"

Yang and Blake leaned forward.

"Get set!"

Ruby and Weiss gripped the steering wheels.

"GO!"

BGM: N64 Rainbow Road (Mario Kart 8)

The four of them immediately took off, leaving Kirby behind in the Formula Star as it was basically a slow Star… for now.

Ruby was behind Weiss and Blake as she ran over a ? box and out came a red shell in her hand. "What the…?" She wondered before throwing it as it homed in on Weiss, hitting her.

"OW!" Weiss yelled as Ruby pulled up ahead. "WHAT WAS THAT FOR?!"

"Don't look at me! It just popped up in my hand!" She said as she took off.

"Why you little…!" Weiss growled as she found a Mushroom from a ? box and boosted ahead, colliding into Ruby and Blake and is right behind Yang. "Hehehe, I'm right behind you."

Yang looked behind and smiled… before dropping a banana peel on the ground as Weiss's eyes widened and swerved out of the way, but unfortunately, she still slipped on it. "WHOOOOOOOOA!" She exclaimed, as she hit the brakes and nearly falling off the edge. "…Phew…" She sighed and backed up, but sadly, Ruby bumped into her and made her fall. "RUUUUUUUUBY!" She screamed.

"…Whoops." Ruby said, looking back as Lakitu caught her and put her back on Rainbow Road, causing her to sigh with relief and proceeding to go on ahead.

"I am so going to kill her later…" Weiss growled as she picked up speed and ran over a ? block and had another Mushroom so she boosted, and then she heard something as something quickly sped past her. "What the…?"

Ruby and Yang were right next to each other, as Blake was right up ahead as the two desperately tried to catch up as Blake had ran over a ? box and was basically firing fireballs from behind, trying to hit the two but they were avoiding the fireballs as Yang drove over a ? box and pulled out a Golden Mushroom. "What the…?"

Yang shrugged it off and tried it out, boosting like crazy. "WAHOOOOOO!" She screamed, leaving Ruby in the dust.

"Oh, that's just not fair!" Ruby sighed and then suddenly, a vehicle sped past her. "What the… was that…?"

Weiss was really behind them and drove over a ? box and had a Blue Shell in her hand. "…Please do something cool…" She said and then threw it, as it quickly took off. "…And it does nothing for me…" She sighed.

But up ahead, Yang was catching up to Blake as she saw the Blue shell from the corner of her eye. "What the…?" She wondered as the Blue shell went past her and hovered up above Blake.

"Huh?" Blake looked up… only for the Blue Shell to dive bomb and explode on her, causing Yang to take the lead.

"WHOA!" Ruby yelled, who saw the whole thing and looked back. "WEISS, THAT WAS A BIT TOO MUCH!"

"HOW WAS I SUPPOSED TO KNOW IT WOULD DO THAT?!" Weiss yelled.

"Ooogh…" Blake groaned as Yang looked back as she was driving away, sighed with relief that she was okay. "Well, that was something…" She said and then someone sped past her. "Was that Kirby?"

Yang saw the finish line in front of her, smirking. "Here we go!" She exclaimed, putting the pedal to the metal, and then heard something behind her and as she turned her head to see what it was… and in a slow motion moment, Kirby slowly sped past her as Yang looked at him in shock as Kirby turned to look at her.

"Hiii!" He waved slowly and then turned back to where he was looking, putting on his determined face as time went back to normal.

"KIRBY?!" Yang exclaimed in shock as Kirby crossed the finish line and hopped off of the Formula Star as the girls pulled up right behind him with Yang being in second, Blake in third, Ruby in fourth and Weiss in fifth.

End BGM

"I didn't know that thing has a lot of speed to it." Yang said.

"Poyo poyo." Kirby smiled as they saw a ? block as Yang punched it, as the vehicles disappeared, then they noticed a sign.

"Hit this ? block to get rid of your vehicles when you are done with them."

"Cool." Ruby said as they walked forward and then they walked forward, laughing about how much fun they had as they saw a clearing ahead of them as they took off to investigate.

World 7-4: Feel the Thunder!

As they walked, a lightning bolt nearly zapped Ruby. "Whoa!" She exclaimed, as they got in position, then they saw a Lakitu floating overhead, but it wasn't just any Lakitu.

It was Lakithunder.

BGM: Boss (New Super Mario Bros Wii/U)

"Oh, you think you can just take US down just like that?!" Yang growled. "Kirby!"

"Poyo!" Kirby nodded and sucked Yang up before spitting her out and becoming Yang Kirby again as the five of them got ready for combat.

Lakithunder proceeded to fire lightning bolts at them as they dodged as Yang and Kirby punched the air, hitting Lakithunder a few times and forcing him to move where Weiss made a cloud as it floated above Lakithunder and it rained fire on him as he screamed in agony and flew around to cool down, as Ruby used her semblance to fly past Lakithunder as the tornado sucked him in and tossed him out of his cloud as he fell to the ground as Blake ran over and jumped up, spinning around and her tail hitting him, knocking him away and into the abyss below.

End BGM

"…That was it?" Yang asked. "The Sumo Bro put up more of a fight than that loser!"

"Poyo poyo!" Kirby exclaimed, dismissing his power-up in favor of doing his iconic victory dance. "Poyo!" He grinned as they wandered around until they saw a Warp Pipe that said 'This way back to the ground!'.

And so, all five of them jumped into the Warp Pipe, as they jumped out and landed on the ground, as they saw the Koopa Kingdom in front of them.

"Poyo poyo." Kirby said as RWBY looked at him. "Poyo poyo poyo poyo!"

He was basically saying that he wishes them the best of luck to save the Mario Bros and Peach while he goes off somewhere else.

"Aww, you're leaving?" Ruby asked, as if she knew.

"Poyo." Kirby nodded and then hugged them all before smiling, waving them goodbye. "Poyo poyo!" He waved and then took off.

The four waved him goodbye and then looked at each other and then at the Koopa Kingdom. "You guys ready?" Ruby asked.

"Yeah." Weiss nodded.

"Let's go." Blake said as they took off.

Meanwhile, with Bowser…

BGM: Bowser's Castle (Paper Mario: The Thousand Year Door)

"WHAT?!" Bowser yelled. "You mean they got through wherever they went and are currently entering MY kingdom… WITH the help of that mangy puffball?!"

"Yes." Koopa nodded. "That is what it is. Fortunately, Kirby left."

Bowser growled. "ALRIGHT, THAT TEARS IT!" He yelled. "SEND EVERYTHING YOU GOT AGAINST THE FOUR… SEND THE GRIMM! EVERYTHING!"

"And what will you do?"

"Prepare for war, of course." Bowser said. "I will show Team RWBY that I will NOT go down so easily!"

"Your Nastiness!" General Guy approached him. "I am feeling much better after my failure at DK Jungle."

"Good! Get the airships ready… and get your tank ready as well!"

"Yes sir!" He saluted and walked off.

Bowser looked out the window and chuckled darkly. "I'd love to see them try get even close to my castle. If they do… I will show them no mercy."

End BGM

Meanwhile, at Dr. Toadley's…

BGM: Dr. Toadley (Mario and Luigi: Bowser's Inside Story)

"A visitor..." Dr. Toadley muttered as he opened his eyes to see Lucario walking in. "The Aura Pokemon. Have I foreseen your arrival? I most certainly have."

"I came here to ask you something."

"You most certainly have. Tell me, what is it that troubles you?"

"I keep having this feeling that something terrible is about to happen. As soon as I saw these Grimm creatures, I know for certain that something was amiss."

"Indeed... it is not just a random encounter that happened overnight. The encounters continue to grow worse each and every time they appear in Toad Town…"

"I had this premonition that something would happen during the Brawl tournament... and then Tabuu made himself known. I am glad we had survived his attacks."

"By the skin of your teeth."

"Yes... and I just want to know something. Surely, this isn't something normal that will continue to be a normal occurrence."

"Indeed."

"Maybe there's something you know. Am I being paranoid, just thinking too much on this?"

"You are right to be concerned." Dr. Toadley's crystal ball lit up. "Ah, the crystal ball speaks... and it..." His eyes darkened and went silent.

"What... what is it?"

There was a darkening silence that went on for several minutes, and even though Lucario is normally patient, he couldn't help but feel a bit agitated.

"It is indeed troubling." Dr. Toadley finally spoke. "It must be stopped before it is too late."

"Who's the source of the problem?"

Dr. Toadley's crystal ball showed an image of Dry Bowser "Bowser?"

"Is it Bowser? It most certainly is not. Is it an ancestor of Bowser that has been awakened for quite some time? It most certainly has."

"Bowser's ancestor?"

"Indeed. He is the source of this problem... but to this Grimm situation, pardon my pun, it is not controlled by him. It is controlled by this woman." He said, showing an image of a certain woman.

"Who is she?"

"I do not know the name... but there will be perilous times if these two were to meet. They must be stopped... otherwise..." He went silent again.

"...Dr. Toadley?"

"...Otherwise, the Mushroom Kingdom, the Smash Mansion, Remnant, and any other places out there... will fall."

Dun dun dun!

Sorry, couldn't help it.