Comet Observatory (Super Mario Galaxy)

"They're coming in a bit hot!" A Luma said.

"Brave yourselves!" Another exclaimed, but the gravitational pull kicked in and they safely landed on the Observatory.

"Ugh…that's the last time I want to get shot out of the cannon…" Hikari groaned.

"Is this our stop? I'd like to get off…" Luigi muttered.

Worldwalker got up. "Well, that went well."

"Hey Cody, look what Hades took." Mokou said as he looked to see Hades holding two certain orbs.

"Thank you for grabbing me."

"Space police! It's the space police!"

"Wheatley and Space Core, huh?" Worldwalker looked at them and smirked evilly. "Yukari, take them to my mansion. I'm pretty sure SHE can use the company."

Yukari chuckled. "You got it." She said as she took the two of them and made a gap.

"Uh…what do you mean by 'she'?" Wheatley asked as they went in.

"Here you go, make yourself at home." Yukari said as she put them down and made a gap back to the other universe.

"Are we still in space?" Space Core asked.

"Oh joy, it's you two…" A voice said.

"Oh no." Wheatley said as he looked to see GLaDOS looking at them.

"Just who I wanted to see. The moron and the space freak."

"How many times have I told you?! I AM NOT A MORON!" Wheatley yelled.

Back with the others…

Hades chuckled. "That's going to be quite interesting in the mansion."

Worldwalker smirked. "Like I said, she could use the company."

"Okaaaay?" Polari blinked.

Mario got up. "Polari? What are you guys doing here?"

"Well, our 'Peach kidnapping' radar kicked in some time ago and we've been trying to get Peach back. However, we also noticed Rosalina being held hostage here, which is kind of strange because Rosalina is with us at the moment."

"Rosalina? So she escaped." Natsu said.

"No, we're still picking up Rosalina in there…" Polari said. "Though, oddly enough, Peach kinda disappeared on us."

"I hope Peach is okay." Mario said.

"I'm hoping that too." Polari said as he saw someone walking up to them in the corner of his eye. "Ah! We were just talking about you."

"I was wondering what the commotion was all about." Rosalina said and then spotted Worldwalker. "…Cody?"

"Hey." He waved.

"Wait, what?" Natsu asked.

"You two know each other?" Happy asked.

"Yeah." Rosalina nodded. "What are you doing up in space?"

"Getting a Crystal Star and going to get my sister out of there." He explained.

Rosalina blinked. "Huh?"

"You see…" Yukari explained everything.

"Oh." She nodded. "I think I got that."

"So Worldwalker's sister is Rosalina from another universe while at the same time, Rosalina in THIS universe is his sister too?" Gray asked.

"This is making my head hurt." Natsu muttered.

"It shouldn't." Minene said. "Because I think I got this figured out."

"I think most of us have got it figured out." Laxus said. "The only one who doesn't get it is Natsu."

"So let me get this straight; your universe's Rosalina jumped into a random portal with you guys, somehow got separated and got captured by the X-Nauts while at the same time our universe's Rosalina is right here and not even noticed by anyone else?" Polari asked as Worldwalker nodded. "Okay, that makes more sense than what a couple of Lumas came up with."

"What was it?" Erza asked.

"Rosalina has a twin sister." Polari explained.

"It seemed plausible at the time!" A Luma pointed out.

"If I had a twin sister, I would've known about it." Rosalina said.

"But never mind about that, we need to go save my sister from another universe!" Worldwalker exclaimed.

"I'm all fired up!" Natsu smirked.

"Lets-a go!" Mario exclaimed.

"Wait, before we go out…something's been bugging me since we were shot to the moon." Gajeel said. "How the heck are we breathing in space?"

Levy blinked. "...Now that you mention it, that is a good question."

Wendy folded her arms. "It's been bothering me too."

"Uh…" Polari blinked. "Logic?"

"Makes less sense than this universe crap." Natsu shrugged. "Oh well, let's go, Happy!"

"Aye, sir!" Happy exclaimed as they all took off to the X-Naut Fortress.

"You're not going with them?" Polari asked Rosalina.

"I could, but…I don't want to cause a universal collapse if I met an alternate version of me."

"Ah yes, better safe than sorry."

X-Naut Fortress (Paper Mario: The Thousand Year Door)

"I'll go save my sister." Worldwalker said. "You guys can go and do what you do best."

"Music to my ears." Natsu smirked. "Come on, Happy! Let's wreck this place to the ground!"

"Aye, sir!" They both took off.

"Wait! You can't hog all the glory, you knuckleheads!" Sting said as he went after them with Rogue and Cobra following them.

"Oye! Salamander! Save some for me!" Gajeel exclaimed as most of Fairy Tail took off.

"Boys will be boys." Carla chuckled and then noticed Laxus running away. "I never thought I'd see you excited to smash things."

Laxus smirked. "I got some anger still inside." He said and took off.

"Well, we might as well go help them. Come on, We-…" Wendy was gone, causing Carla to sigh. "Kids." She smiled. "Hey, wait for me!" She took off.

"Leave some chaos for me!" Hades took off.

"Save a piece for me to blow up!" Minene exclaimed.

"I'll go with you." Mokou told Worldwalker as he nodded.

"I'll gap you to the room." Yukari said as she made a gap as they both went in. "And now, if you'll excuse me…" She cracked her knuckles. "I believe a couple of X-Nauts called me a hag at one point."

Outside…

"Good lord!" Polari exclaimed with a sweatdrop.

"Never thought they'd be that rowdy." Rosalina blinked.

Back with the others…

"Hello, R.O.B." Worldwalker said as the robot turned around to see them.

"Cody! Mokou!" Rosalina exclaimed happily.

"I will dispose of the two of you…and then I will destroy her." R.O.B. said.

"Bring it on, tin can!" Mokou's hands ignited.

Rinzler Recompiled (Kingdom Hearts: Dream Drop Distance)

R.O.B. charged up his gyro and then launched it, but they dodged as they ran over as Worldwalker slashed him while Mokou threw fireballs over to him. "Useless." He said as he used Robo Burner to fly up, and then attacked Worldwalker from above, but then Mokou grabbed him and threw him to the side, launching a fire blast at him to knock him to a wall.

Worldwalker picked up the gyro and carefully aimed it at R.O.B., and then he threw it at him, but he used Arm Rotor to reflect it back and hit him. "Hmph, well played!" He said as Mokou flew over and kicked him away, only for R.O.B. to use a charged up Robo Beam to send her flying, but she recovered.

"Let's see if you like this. Deathless: Xu Fu's Dimension!" She called out as R.O.B. attempted to send them back with Arm Rotor, but that got him nowhere as Worldwalker slashed him several times and then he got hit in the face with a couple of fireballs.

"Prepare to get sent to the scrap heap!" Worldwalker exclaimed as he ran straight for him.

"Time to be executed." R.O.B. said and then used Super Diffusion Beam on Worldwalker and sent him flying near the control panel and slammed into it, causing it to short circuit. "Now there is one left to be eliminated."

"Make that two!" A voice said as R.O.B. turned and Rosalina kicked him in the head.

"What? Impossible, you should be trapped!"

"You sent my brother to the control panel, which broke it and released me." She said as she summoned a Luma.

"I didn't intend to save her like that." Worldwalker got up. "But hey, what are you gonna do about it?" He asked.

"All three of you will be exterminated!" R.O.B. exclaimed and fired a Robo Beam, but Rosalina used Gravitational Pull to make the Robo Beam disappear.

"Undying: South Wind, Clear Sky Soaring Kick!" Mokou shouted as R.O.B. was sent to another wall and then a Luma was shot out and slammed into R.O.B. to finish him off…and he broke apart.

X-Naut Fortress

"Well, that takes care of him." Worldwalker said.

"I feel kind of bad, though…he's been reprogrammed to act like that." Rosalina said.

"Well, maybe we can reprogram him back to his normal self." Worldwalker said. "I wonder if Nitori's not too busy at the moment." He wondered as they walked out to see an Iron Club going through the hallway and knocking out several X-Nauts.

"Take that, you freaks!" Gajeel said.

"Hey uh, Gajeel? Where's Nitori?" Worldwalker asked.

"How the heck should I know?" He shrugged as he noticed a tidal wave coming in with several X-Nauts screaming and Nitori surfing on it. "…Found her."

"Surfs up, dudes!" Nitori said as she fired danmaku at their legs before swallowing them up in the water as she landed near them.

"Hey, do you mind if you reprogram this guy?" Mokou pointed to R.O.B.

Nitori nodded. "Leave it to me." She said as she walked in while Gajeel ran off to destroy more things.

"On a rate of one to ten…how do you rate that tidal wave?" An X-Naut groaned.

"7.8…it was too much for me." Another groaned. "Too…much…water…" He said as the ground underneath them exploded as Minene was underneath them.

"Ah, I love the sounds of explosions in the morning." Minene grinned.

With Crump…

"What in blazes is going on out there?!" He asked as pieces of ceiling were falling on top of him as the door opened up and he saw Natsu, Happy, Erza and the Mario Bros standing right there. "Uh oh."

"Alright, you freak! Where did you put Peach?" Natsu asked.

"She's not here! She's at the Thousand Year Doo-" A chunk of ceiling landed on top of him. "OW!"

"She's in the Thousand Year Door?!" Mario exclaimed.

"Hmph, we'll take the Crystal Star and get out of here." Erza requipped into the Ike Amiibo outfit. "Prepare yourself." She said, aiming the Ragnell at him.

"Oh, you think you've won with that outfit on? Well we'll see if you can actually win with Magnus Von Grapple 2.0!" He said as he went into the machine and started walking to them…and just in time too, because a support beam landed where Magnus Von Grapple 2.0 was at.

Magnus Von Grapple (Paper Mario: The Thousand Year Door)

"Prepare to be exterminated!" He exclaimed as he ran over and punched Natsu, but he blocked with one hand, but it did cause him to slide a little.

"Hmph, let's see if this robot has high defense!" Natsu said as his other fist burst into flame. "FIRE DRAGON'S IRON FIST!" He yelled and punched Magnus Von Grapple 2.0 away and nearly causing it to fall from the debris.

"Whoa!" Crump exclaimed as he then hit by Mario and Luigi doing Knockback Bros and then Erza slashed Magnus Von Grapple several times. "Alright, let's see if you like this!" He said, as he sucked up several pieces of debris and launched them at the group, but they dodged and the debris caused even more of a mess, even destroying the doors.

"AETHER!" Erza yelled and slashed down on Magnus Von Grapple.

"You Fairy Tail freaks are going to perish!" He said as he launched his arms like missiles, but Natsu and Erza slashed them away and they exploded once they hit the walls. "Hey, no fair!"

"FIRE DRAGON'S BRILLIANT FLAME!" Natsu yelled as Magnus Von Grapple 2.0 stumbled and fell to the ground, and starting to malfunction.

"Oh, this is bad!" Crump exclaimed as Erza ran over to him and then a rainbow-like aura surrounded her as she slashed up to send Magnus Von Grapple flying in the air.

"GREAT…AETHER!" She yelled as Crump was screaming…and then she slashed down and caused Magnus Von Grapple to explode and Crump was sent flying out of the X-Naut Fortress.

"I'LL REMEMBER THIIIIIIIIIIIS!" He yelled as a star shined brightly in the darkness of space.

"We did it!" Luigi exclaimed and high fived Mario while Erza picked up the Crystal Star.

"Come on, let's go." She said as they nodded and took off.

I was going to end it after ROB's defeat, but I thought "Nah, let's have Crump get annihilated!"