Tanjiro woke up abruptly in a dimly lit and empty hallway. How he got there, he couldn't figure out. The last thing he remembered was being on the Mugen train with Kyojuro, his sister, and his friends on that train.

"Where are we?" Tanjiro asked. But, he got no response. "Guys?" Tanjiro started to panic as he looked around in a frantic search for any of his comrades, but they weren't to be found anywhere in sight. With one last gulp, he reached behind him to feel for his backpack that was supposed to have his sister in it…

Nothing.

Tanjiro began to breathe heavily in a severe state of panic. Tanjiro didn't know where he was or how he got there or where his friends and sibling were. He was snapped out of his crisis when he heard a faint voice.

"Let's give a warm welcome to today's fighters!"

Tanjiro began to calm down as he figured out that other people were here. Tanjiro decided to ask around in hope that somebody could help him. He walked throughout the building he was in as more light filled the hallways as he walked. He looked to his left to see that there was yet another hallway that seemed to lead outside. He kept walking while the voice from earlier spoke as well as the sound of a large crowd.

"In the right corner, we have Mr. Video Game himself, hero of the mushroom kingdom and lover of mushrooms. You know him, you love him, MARIO!"

The crowd went wild as Tanjiro walked closer to the opening outside. The voice spoke again.

"And in the left corner, we have the puffy pink terror, the atrocious yet adorable alien from planet popstar, please welcome, KIRBY!"

Tanjiro finally reached the outside to see that he was in a huge arena with a VERY large crowd in the stands. Tanjiro looked ahead to see two people watching what was going on. The first was a woman with long, brown braided hair. She had elf ears, which almost made Tanjiro mistake her for a demon if not for her not-so-hostile scent. She wore a long, white dress with a purple top over it as well as long white gloves on her hands. She also wore a golden headband on her head and two golden shoulder pads on her shoulders.

The second was another woman with long blond hair and in a long pink dress. She had a small crown on her head as well as two white gloves on her hands.

It would seem that these two were watching what was happening in the arena. Tanjiro decided to ask them for help.

"Um, excuse me?" Tanjiro said, politely getting their attention.

"Hi there!" the woman in the pink dress greeted.

"Who might you be?" The woman in the purple and white dress asked.

"My name's Tanjiro Kamado." Tanjiro greeted. "And...um...I'm kind of lost. I don't know where I am or how I got here."

"My, that is a rather strange predicament." The brown haired woman said. "You're in the Midair Stadium, my friend."

"Midair...Stadium?" Tanjiro asked, confused.

The two women exchanged concerned looks with each other. "I'm afraid we don't really know how else to help you, Tanjiro." The blonde haired woman said. "But for now, if you would like you can watch the match between Mario and Kirby with us."

"Who?" Tanjiro asked before looking to the arena. He saw two people fighting. The first was a rather short man with a mustache who wore red clothing and blue overalls. He had white gloves, brown shoes, and a red cap with a white circle with a red letter M on it.

"The man in red is Mario." The blonde girl said. "And he is fighting Kirby."

She pointed to Mario's opponent. It was...uh...Tanjiro didn't really know what it was at first. It was a weird, small, pink, blob creature with nubby little arms and two dark pink feet and an adorable face with looks that could rival Nezuko's.

"I see." Tanjiro said, a little confused, but he got the idea.

"Oh! We forgot to introduce ourselves. Where are our manners?" The brown-haired woman said. "I am Princess Zelda of Hyrule. It is a pleasure."

"And my name is Princess Toadstool of the Mushroom Kingdom." The blonde-haired woman said. "However, a lot of people just call me Peach."

"Princesses?!" Tanjiro exclaimed before he bowed in respect of royalty's presence.

"While your respect is greatly appreciated, you can drop the formalities." Zelda said.

"I insist!" Tanjiro said.

"No really, you don't have to-" Zelda was cut off by the crowd. The three of them looked to see that Kirby had become victorious and Mario had become...

"Gah! He's a statue!" Tanjiro exclaimed.

"It's 'trophy' actually." Peach explained. "And don't worry, Mario's fine. Watch."

Tanjiro watched Kirby walk up to the 'Trophy' of Mario. Kirby then tapped the base of the Trophy as it then started to glow. One flash of bright light later, Mario was back to normal.

"He's back to normal." Tanjiro said. "What just happened?"

"To be honest, we're not entirely too sure ourselves." Zelda said. "One day, Mario and another friend of mine were sparring, one of them got knocked high into the air, so much that we couldn't even see him, and when he came back down, he was a trophy."

"This kept on happening for about a year, until eventually it just became a normal thing and everyone grew used to it." Peach explained. "Don't worry, I'm sure you will too eventually."

Okay, Tanjiro knew that knocking someone out so hard, they turn into a 'Trophy' definitely wasn't a normal thing where he was from. He may be a little bit more far from home than he thought.

Just when Tanjiro decided to give up and go look somewhere else for help, the sound of fear and concern from the audience as well as the ground shaking stopped him. He turned around to see that the sky had turned Blood Red and a giant metal ship with wings appeared from the clouds.

"Oh no, now what?" Tanjiro thought. "Is this a part of the match?" He asked.

"Not that I know of…" Peach said with concern. "Zelda?"

"No, me neither…" The princess of Hyrule replied. Kirby and Mario exchanged glances as well. Kirby had the most worried face as he recognized the ship immediately; the Halberd.

Just then, a hole underneath the Halberd opened up releasing strange, small, purple particles in the arena. Once they landed on the arena floor, they gathered together in chunks to create...Tanjiro couldn't even describe what these were.

(Hi author here, y'all know what Primids look like right? Ok cool just checking.)

The purple particles created at least 3 dozen of them from a rough geuss. These were called Primids, low tier minions of another mysterious being.

"Primids." Peach said bitterly.

"You know these things?" Tanjiro asked.

"It is a rather long story." Zelda told him. "But right now we need to stop them before someone gets hurt!"

Zelda and Peach then did something unexpected. Peach leaped into the air before pulling out a pink parasol. She then floated down elegantly next to Mario and Kirby. Zelda on the other hand teleported herself next to Mario, Peach, and Kirby.

Tanjiro watched in awe as the 4 of them prepared to fight the Primids. Tanjiro looked at the pyramids. Even though they didn't look hostile, the scent they gave off told the young Demon Slayer otherwise. Looking for his friends and his sister could wait, right now though, these Primids needed to be eliminated.

Tanjiro drew his sword before leaping after Peach and Zelda. He landed next to Mario.

"Who's the new guy?" Mario asked in a strong, Italian accent.

"Hai!" Kirby said.

"I'm Tanjiro Kamado." Tanjiro introduced himself. "And we need to eliminate these things."

"You're-a speaking my language, Tanjiro." Mario said. "Sick 'em, Kirby!"

"Poyo!" Kirby exclaimed before inhaling a few of the primids. He then spat them back out at another group of baddies, knocking them into the pit below them.

"Let's a-go!" Mario exclaimed as he threw fireballs at his foes. A few of them lit up in flames before poofing out.

Peach hit a few Primids with her frying pan while Zelda casted Din's fire on a few of them.

Tanjiro readied his blade when 6 of them surrounded him. He knew exactly how to deal with this.

"Total Concentration, Water Breathing: Sixth Form!" Tanjiro then began to run through, past, and around the enemies, all the while performing a spinning motion. Tanjiro sliced through the Primids with ease while performing the Breathing Technique. "Whirlpool!"

Tanjiro took out a lot of the Primids using the same Breathing Technique twice with a little help from Peach, Zelda, Kirby, and Mario of course. But then came a new enemy: the Spaaks.

The Spaaks were literal clouds with two red beady little eyes and an electric generator inside of their bodies and an electric battery on top of them. Tanjiro gulped as he knew that water and electricity and water would not make a good combination, not in this situation at least.

He was also briefly made to think of his blonde-haired friend, Zenitsu. Tanjiro wondered if his friends were in this strange new world as well.

Tanjiro was snapped out of his thoughts when he saw three Spaaks flying right towards him Tanjiro readied himself yet again. "Total Concentration, Water Breathing: Seventh Form!" Tanjiro pulled back the tip of his sword and at the right moment thrusted it forward as if it were fencing. "Drop Ripple Thrustcurve!" The Spaak's were launched in three different directions, 2 of which got them KO'd.

"Tanjiro, behind you!" Peach cried out. Tanjiro turned around to see that a black, angry Spaak was flying straight towards him at high speeds. But before Tanjiro could react, Mario jumped over him and hit the Spaak with a downward punch (FORWARD AERIAL), Ko'ing it.

"Thank you, Mario!" Tanjiro said.

"Don't-a thank me just yet." Mario replied. "We still have more fish to fry."

With three more slashes to end it, Tanjiro knocked out the remaining Primids and Spaaks, clearing the arena. Tanjiro took a deep breath before thinking to himself. "Why did that feel...too easy?"

The young Demon Slayer then heard a strange noise. He, as well as Kirby, Mario, Peach, and Zelda, looked up to see a figure in a dark green outfit that covered them completely except for their glowing yellow eyes. The figure was flying down to them on some weird floating device while carrying something Tanjiro couldn't make out.

"Who is that!?" Tanjiro exclaimed.

"I'm afraid that I can't say that I know." Zelda said, solemnly.

"I haven't a clue either." Peach said, her hand softly covering her mouth.

"Poyo…" Kirby shook his head in confusion.

The hooded figure was known as the Ancient Minister. A mysterious figure who keeps himself laid low. One thing is for certain, however. He is on the side of evil for unknown reasons.

The Ancient Minister dropped a large, metal ball. Then what appeared to be two robots on wheels appeared from behind it. The two robots then planted both of their arms inside the metal ball, pulling it open to reveal blue electricity, a small floating black orb, and…

...a timer...counting down from 3 minutes.

Tanjiro and Mario both spoke at the same time. "IT'S A BOMB!"

The Ancient Minister was silent as he gave his two R.O.B. minions a soft nod before flying away, back into the Halberd.

"We've got to stop it!" Mario said before sprinting towards the Bomb. Tanjiro was about to join him until…

*SLAM*

Tanjiro felt a small shockwave through the ground. He detected another scent from behind him. The five of them turned around to see something that was covered up by a large cloud of dust. Then, a cannonball flew out of the smoke as it knocked Mario into the sky and out of the arena.

"Waaaaaaaaaaaaa!"

"MARIO!" Tanjiro called out.

Kirby looked up to where his friend was launched only for him and Tanjiro to hear Peach's scream. They turned to see that said princess along with Zelda were in cages, held by a monster. This monster had a plump green torso and small legs for its size. It wore a red speedo with white polka dots on it. The monster looked like a combination of a sunflower and a venus fly trap with two giant leaves for arms.

This monster was known as Petey Piranha, one of the many minions in the koopa army of King Bowser. He was sent to eliminate Mario multiple times, but has never succeeded once. Until today…

"Oh great…" Tanjiro thought to himself.

Petey Piranha slammed Peach and Zelda's cages together before roaring at Kirby and Tanjiro.

"Poyo!" Kirby exclaimed before jumping to deliver three kicks to Petey Piranha, only to be knocked away by one of the cages holding the princesses.

Tanjiro ran towards Petey before leaping high into the air. "Total Concentration, Water Breathing: Second Form!" Tanjiro then began to close in on the monster while rotating his body clockwise. He then began to spin horizontally. "Water Wheel!"

Petey Piranha countered Tanjiro's attack by shooting a fireball out of its mouth. Tanjiro was then knocked out of the air, but regained himself quick enough to land on his feet. The Star Warrior and Demon Slayer tried many times to get in close, but the Bowser Minion had countered or blocked their every move. Tanjiro tried to run around him to see if he could attack from behind. But Petey was quick in reaction time as he leaped high into the air before coming back down, slamming onto Tanjiro with the princess-full cages, had he not dove out of the way.

Tanjiro growled in annoyance. "We can't seem to land a hit on this guy, what gives? For someone with no eyes he sure does have a good grip on his surroundings. He can hit us from far away by shooting flames from its mouth. And don't get me started on those cages with Peach and Zelda in them...wait!"

"Kirby!" Tanjiro called to his pink, puffy friend. "Forget him, focus on getting Peach and Zelda free! Destroy those cages!"

"Poyo!" Kirby nodded in understanding before running toward Peach's cage. Petey Piranha tried to spit another fireball at the puffball, but Kirby inhaled it, transforming into Fire Kirby. He then began to run faster, becoming a fireball himself, ramming into Peach's cage and thankfully not bringing any harm to the Mushroom Kingdom Princess. This only did some damage however, as the cage was still standing. Tanjiro looked at Kirby's powers in awe before focusing back on the battle. He ran towards the cage in a serpentine motion as to not get hit with an attack. Tanjiro sliced through any fireballs that he just so happened to line up with his path. As soon as he neared Peach's cage, he reeled back his sword one final time.

"Water Breathing: First Form!" Tanjiro swung his sword horizontally in front of him, cutting the lid of the cage clean off. "Water Surface Slash!"

Unfortunately, what Tanjiro and Kirby didn't know was that the cages were explosive. So the first form of the breathing technique made both of the cages explode, all the while taking Petey Piranha down with them.

Tanjiro looked on in panic, worrying that death had accidentally befallen the two princesses. But Peach landed next to Kirby safely. "Wait a minute, if Peach is alive, then where's…?"

Tanjiro looked around him before letting out a sigh of relief, seeing as both princesses were safe. Zelda had landed a few yards away from them.

"Thank you, Kirby." Peach said in gratitude. "You as well, Tanjiro."

Tanjiro took a deep breath to regain himself. "Yeah, no problem." Tanjiro waved it off. But just before he thought he could catch a break. He detected YET ANOTHER scent. And wouldn't you know it, it was ANOTHER hostile one.

"Someone else is coming." Tanjiro said, pulling his sword back out of its sheath. "Be ready." Kirby and Peach readied themselves as well. The scent was growing stronger, meaning that whatever it was getting closer...and closer...and closer, until Tanjiro could tell what the scent was directly.

It smelled like…

…

...Garlic?!

In case it wasn't clear, this story takes place DURING the Demon Slayer Movie.

Consider leaving a review on this new story of mine! Let me know what you guys think of the idea of Demon Slayer: Kimetsu no Yaiba and Super Smash Bros. Brawl: Subspace Emissary!

If you have some suggestions for things I could add to this story, let me know. I would love to hear them. Heck, IF I like your suggestions so much, I might as well include it in this story.

Farewell for now!