Disclaimer: Kingdom Hearts belongs to Square Enix and Disney. Nintendo franchises belongs to Nintendo. Persona 5 belongs to Atlus and Sega. Code Vein belongs to Bandai Namco and Ufotable.

Ford1114's A/N: Hello everyone. This is a non-canon collaboration between Akane no Mai by Kanius and myself, and the upcoming Kingdom Hearts: The Nintendo Version Remixed by KingdomKey23. It is similar to how Persona 5 has collaborations with various franchises in Japan such as Granblue Fantasy.

Because this is non-canon, I can allow myself that this one-shot is set around Kingdom Hearts III. This marks the first time in fanfiction history that a friend of the original author contributes something neat (Such as finally expands outside the box of post-KH2, opening doors for allowing freedom) and earn his blessing.

Enjoy this collaborative one-shot.

xxxxx

Akane no Kingdom Nintendo

Written by: Ford1114

xxxxx

The Velvet Room

In a lone prison realm showed a rotting wooden desk. A single bulb is hanging over the desk and illuminated the spot.

Sitting in the desk is a mysterious man. Although, one could wonder from first glance if this 'man' was really human. He had features uncharacteristic for a human. He had the physical features of an elder man but a long beak for a nose and wide bulging eyes that appeared bird-like. He had tufts of gray hair around the back of his head and thick black eyebrows. He wore a black suit and white gloves. He raised his head, grinning wide.

"Welcome to the Velvet Room." The mysterious figure addressed himself, "My name is Igor. And we are here to tell the story of the chosen one, Sora. He has been an adventurer throughout worlds in meeting companions and combating the darkness."

Igor then showed visions of the hero's adventures. It is set in a fictional crossover universe filled with wondrous Nintendo franchises that portray the existing roles of Disney.

The first showed past events such as Sora, Luigi, and Yoshi becoming the iconic Nintendo Trinity. Exploring the worlds of Metroid, Pokémon where they meet the legendary trainer named Red, Donkey Kong, The Legend of Zelda with the events based on Ocarina of Time, Kirby, F-Zero, and Sonic the Hedgehog. The Nintendo Switch system is seen within the Nintendo Trinity's supplies. The events of Hollow Bastion, such as fighting Bowser in his normal and Giga Bowser forms. The battles against Ansem, Seeker of Darkness. The events of Castle Oblivion, leading to the Nintendo Trinity falling asleep for a year to regain their real memories.

The events of II are shown. The Nintendo Trinity exploring Twilight Town. Wario and Waluigi made their appearances. Sora and his friends meet the legendary Shigeru Miyamoto, who is Mario's master and a former Keyblade wielder. Mario is seen using Cappy. Exploring the world of Banjo-Kazooie in reuniting with a certain bear and bird since Sora used them as Summons back then, especially around the world of Donkey Kong. Sora and friends meeting Auron while exploring Team Rocket's Headquarters, they also assist Red and his friends against Ghetsis & Hydreigon, alongside competing Giovanni's tournament cups. Sora and friends go to the Mushroom Kingdom in reuniting with Princess Peach, Daisy, Toad, Toadsworth, and Professor E. Gadd; alongside exploring the retro world of 8-Bit Mario. Sora and friends meet Rosalina. The world exploration of Metal Gear and meeting Solid Snake. Returning to the world of Zelda with the events of Twilight Princess. Reuniting with Ness in the world of Earthbound since Sora once use him as a Summon, they team up to face Porky Minch and later Giygas. Meeting Mega Man inside Hollow Bastion/Radiant Garden's computer. The battle against 1,000 Heartless, but it is clearly an easy battle since Sora uses Reaction Commands to wipe out all the enemies besides Luigi and Yoshi backing him up. Sora teaming up with Fox McCloud to face Xaldin. Sora and his friends fought Tabuu summoned by Xemnas. The confrontation against Organization XIII and Xemnas. Afterwards; Sora, Riku, and Kairi finally return home in Destiny Islands.

Sometime later in segue to the Dream Drop Distance, images shown Sora and Riku in the Sleeping Worlds for their Mark of Mastery Exam. One of which is Riku fighting Master and Crazy Hands summoned by Young Xehanort, who corrupted the two hands to become the Master Core. Another is exploring the world of Paper Mario of helping a paper version of Mario and his allies against Dimentio. This lead to the events of Master Xehanort's return with the real Organization XIII and gathering the Seven Lights for the coming battles.

Afterwhich, Sora seeks to regain his strength and the Power of Waking. In the Pokémon League that started the II.9 event; Sora, Luigi, and Yoshi reunited with Red, his Pikachu, & Mega Charizard X and the other trainers to fight Team Rainbow Rocket consisting of Giovanni & Mega Mewtwo X, Ghetsis & Dynamaxed Hydreigon, Cyrus & Dynamaxed Weavile, Lysandre & Mega Gyarados, Maxie & Mega Camerupt, and Archie & Mega Sharpedo. Among the allied trainers seen are Blue & Mega Blastoise, Green & Mega Venusaur, Ethan & Typhlosion, Lance & his three Dragonites, and Cynthia & Garchomp. The characters mention about the Galar region alongside two legendary wolves that each one is armed with a sword and shield. Lance's Dragonites are named Azrael, Ibris, and Djibril. Lance also mentioned that his cousin, Clair, named her Dragonite, Kisara. Bowser, Wario, and Xigbar are encountered in that world. Sora and his friends even fought Primal Groudon, and used the Spirit Train Attraction in using the spirit tracks and fireworks on the legendary Pokémon before the showdown against the evil team.

The battle royale against Team Rainbow Rocket are specifically shown: Blue & Mega Blastoise vs. Archie & Mega Sharpedo. Green & Mega Venusaur vs. Maxie & Mega Camerupt. Ethan & Typhlosion vs. Lysandre & Mega Gyarados. Lance & his three Dragonites vs. Ghetsis & Dynamaxed Hydreigon. Cynthia & Garchomp vs. Cyrus & Dynamaxed Weavile. Sora, Luigi, Yoshi, Red, Pikachu, and Mega Charizard X vs. Giovanni & Mega Mewtwo X. This is clearly a big opening event of what's to come for Sora.

Now the recent events of III has properly started: Sora and company met Cooking Mama at Twilight Town. Luigi lets out a repetitive dialogue saying, "This might be a good spot to find some a-ingredients!". Bowser, Bowser Jr., the Koopalings, Wario, Waluigi, and the Broodals are finding the mysterious Black Box. Sora assisting Pit and Palutena to fight Hades. The world of Kid Icarus is aware that their in a fanfic crossover series written by a friend of the main fanfic author living in a different universe, while the main fanfic author is creating a new universe for a Remixed of his old fanfiction crossover. Sora and the Ice Climbers are fighting the wolf Heartless, Sköll. Sora summoned Link in his Breath of the Wild incarnation to fight a number of Heartless that formed into a shape like Calamity Ganon. The reunion with Solid Snake. Sora teaming up with Spider-Man by exploring the vast New York City, alongside both taking a selfie, these events take place after Spider-Man stopped Doc Ock and the Devil's Breath outbreak.

Afterwards, Sora ventured to the Realm of Darkness to save Riku and Mario from Anti-Aqua, alongside saving Aqua from the darkness within. Then, the heroes went to the Land of Departure in saving Ventus from Vanitas, while Sora finally gets the Power of Waking. Miyamoto has gathered the Seven Guardians of Light and allies: Sora, Riku, Kairi, Mario, Luigi, Yoshi, Lea, Aqua, and Ventus of preparation of the final battles ahead.

"And here we are, with Sora and his friends are venturing to a world to meet the urban tricksters." Igor announced the coming event.

xxxxx

World: Shibuya

Shibuya, one of the major commercial cities in Tokyo, Japan. This is the site where a group of eight teenagers have these special powers called Personas, manifestations of people's feelings and hearts. These teenagers are called the Phantom Thieves, and their goal is to steal the treasures of corrupted figures' hearts and changing the flawed society within justice. The names of these members are Ren Amamiya/Joker, Morgana/Mona, Ryuji Sakamoto/Skull, Ann Takamaki/Panther, Yusuke Kitagawa/Fox, Makoto Niijima/Queen, Futaba Sakura/Oracle, and Haru Okumura/Noir.

One day, a strange group of monsters are seen attacking Shibuya. Caught by surprise, and how their presence caused the Phantom Thieves to utilize their Metaverse powers in the real world.

The Phantom Thieves are now seen fighting a thousand of these dark creatures called the Heartless in the Shibuya streets. The Heartless seen are Neoshadows, High Soldiers, Flutterings, and Metal Trolls. Besides that, a group of Reaper Nobodies and Spiked Turtletoad Unversed back up the Heartless.

"What are these things that we're fighting?!" Skull yelled.

"From the looks of it, they're not even Shadows!" Mona answered, which is ironic how there are Shadow and Neoshadow Heartless.

"And what's worse, since they're in the real world, Shibuya is in danger." Queen warned.

"There's too many of these things!" Skull cried out.

All of a sudden, a slash towards a High Soldier Heartless is heard out of nowhere as the creature disappeared. It sounded like being hit from a key of some sort. The Phantom Thieves turned to see three figures.

One is a teenage boy with brown spiky hair, yet the spiky part is downplayed unlike his younger years. He wore a black jacket having grey pockets and a stripe of the same color on each sleeve. The hood, sleeves and jacket have a red lining and six buttons can be seen on the front. Underneath he wears a black shirt with a V-neck style collar and a white lining. He wore gauntlets that are designed like his jacket with the exception of a grey circle on the backs. The palms of his hands are exposed. He wore black shorts with armored sidings that appear to be attached by red straps that wrap around his legs. He had black shoes with yellow linings. As usual, he wears his crown necklace. His name is Sora, and that he brandished a Keyblade called the Kingdom Key.

The other two are his companions: One is an Italian plumber with green clothing such as his hat named Luigi, to which he brandished his Save the Queen+ staff. The other is a friendly, green dinosaur named Yoshi, who he brandished his Save the King+ shield.

"Organization XIII must have block a pathway on the way to the Keyblade Graveyard!" Sora stated to his friends. Indeed, while the trio are on their destination, the dark force from their enemies made them took a wrong turn to this destination.

"Yeah, they must have forced us to go to this world to clear this a-special stage!" Luigi agreed from his Italian accent.

Sora and his friends then turned to the Phantom Thieves. Apparently, both sides are obviously on the same boat of fighting these dark enemies.

"Hey, thanks for helping us, just wonder who are you guys?" Panther asked.

Sora responded with his trademark smile.

"I'm Sora! And these two are my friends, Luigi and Yoshi!" Sora introduced with his two friends nodded towards the Phantom Thieves.

"It's nice to meet you." The leader of the urban vigilantes answered. "I'm Joker, and we are the Phantom Thieves."

"We could use a helping hand with these things." Mona offered.

"No biggie! We're good in helping against these monsters!" Sora positively responded.

The battle begins as Oracle inside her Necronomicon Persona boosted the party members' stats. Sora used Waterga that conjured streams of powerful tides at the Reapers and a Metal Troll. Yoshi bashed some High Soldiers with his shield with Fox assisting by slicing some down with his katana. Fox summoned his Goemon Persona, as he unleashed a freezing Bufu on Flutterings.

The Metal Troll injured by Sora's water magic gets up and is about to strike with its axe. However, Skull arrived with his Captain Kidd Persona in unleashing a Zio thunder attack to stun the Heartless before hitting it with his mace. Sora and Ann w/Carmen Persona arrived, with Ann used the fiery Agi to land a direct hit at the Heartless. Sora used Ars Arcanum that delivered a flurry of strikes with his Keyblade before he finished the Metal Troll off.

Sora then switched his Kingdom Key to another Keyblade named Poké Origins, received after Sora's visit from the Pokémon League. Sora and Joker teamed up in taking down some Heartless. A Spiked Turtletoad and a Metal Troll approaches. In response, Sora's Keyblade effect activates to form change into a bazooka-like Keyblade shape filled with Poké Balls.

Sora then shoots three Poké Balls from his transformed Keyblade to call forth a Squirtle, Ivysaur, and Charizard. In response, Joker called forth his signature Persona, Arsène. The two heroes continued their assault at the enemies, with Sora striking down a Fluttering with his Keyblade and Joker slash down a Neoshadow a few times with his dagger before the Heartless is killed. Joker used an Eiha by snapping his fingers to fire a dark flame at another Neoshadow to destroy it. Squirtle used his Water Gun from his mouth to spray down High Soldiers. Charizard beats down a Metal Troll and used Flamethrower on it. Ivysaur grappled with a Spiked Turtletoad with his Vine Whip.

Then, Sora then commanded the finisher from his transformed Keyblade, Triple Finish, which has Fire Blast, Hydro Pump and Solar Beam combined from the three Pokémon to wipe out a group of Heartless and Spiked Turtletoads. The Keyblade is reverted back to normal as the summoned Pokémon disappeared.

Meanwhile, a few Reapers are about to strike with their scythes, but Queen blocked them with her fists and beats one Nobody down in disarming its scythe. Then, Queen grabbed the scythe in slicing the Reapers down before they disappeared. The scythe disappeared. Queen hopped into her Johanna Persona that's shaped like a motorcycle for her to strike through Neoshadows and High Soldiers with her Persona and Frei nuclear spell. Noir with her Milady Persona backed up Makoto by firing her grenade launcher at the Heartless.

Then, Sora summoned one of his Attraction abilities, a set of three Mario Karts for himself, Yoshi, and Luigi to ride on.

"Let's Mario Karting!" Sora announced as he and his two friends drive towards the Heartless.

The Phantom Thieves are impressed by this.

"Whoa! You got some go-karts in beating their tails high!" Skull hollered.

"They look impressive, though I still prefer riding Johanna." Queen calmly commented.

"Wish I should ride one myself, what do you think, Inari?" Oracle asked the kitsune-masked Phantom Thief.

"It sure to be intriguing for a spare race across Shibuya's streets." Fox answered.

While Sora use his kart to crash down Heartless, he fired countless Firaga to take out some High Soldiers and Flutterings. Luigi gave his trademark death glare at the Heartless while using his Mario Kart in mowing them down. Yoshi threw a green turtle shell at the Heartless and a Spiked Turtletoad as the shell kept bashing through the enemies. Upon having enough power from his fire spell, Sora unleashed a devastating Firaza that delivered a huge fiery impact to wipe out the remaining Heartless.

The Mario Karts then disappear after being used. Just as things are about to be cleared, the Phantom Thieves' navigator alerted something.

"Danger, guys!" Oracle announced to her teammates. "We have a big wave of bad energies coming!"

Suddenly, the skies have darkened as an ominous sign. A huge dark portal materialized in the skies.

Coming out of that dark vortex is a colossal black tentacled monster with a single sinister eye that intimidated his coming opponents. The eldritch monster let out an unholy screech, as if its trace from the ancient, unimaginable darkness.

"The heck?!" Skull yelled.

"It's so creepy looking!" Panther cried out in disgust.

"W-What is that thing?!" Sora shouted.

"Mamma-mia! I've heard of this thing in a-stories and even the Mushroom Kingdom heard the legends!" Luigi shivered in fear when seeing the abomination, "He's a-Dharkon, a monster made out of pure darkness and chaos. He and his light counterpart, Galeem, have always fought each other in their endless cycle!"

Besides Luigi, Yoshi is seen giving the slight shivers in the background.

"Can't believe Organization XIII actually summoned him!" Sora glared at Dharkon.

"Remind me how Ansem once summoned both a-Master and Crazy Hands before." Luigi groaned of some similar connection.

"Yeah, how can I forget!" Sora recalled when he and his friends fought the hands back in the End of the World.

All of a sudden, more Heartless are summoned by Dharkon, as they menacingly approach their oppositions.

"Great, just as we needed." Queen gritted upon seeing more enemies.

Mona then turned to Joker, "Joker, we'll fend off these Heartless. You go help Sora and his friends against that monster."

"On it, Mona." Joker nodded at the anthropomorphic cat.

Just then to some people's surprise, Sora then called out two Summons: Bayonetta and Kirby. The Phantom Thieves are impressed the way the Keyblade hero summoned them.

"We could use some help taking down Dharkon." Sora responded upon doing this act.

"Hey there, boy. You thought you could use some help with mommy." Bayonetta first saw interest of the Phantom Thief leader and gave an encouraging smile at Joker.

"Um, yeah sure." Joker hesitantly responded.

Kirby then absorbed Joker before instantly spat him out. Much to the Phantom Thieves surprise of the former act, and seeing Kirby's appearance, the cute pink being has gained Joker's mask, unkempt hair, and pistol.

"Man, I've seen weirder things, but this takes the cake." Skull commented on Kirby.

"Yeah, this is something to get use too." Joker muttered before resuming the focus. He then resummoned Arsène behind him as the Phantom Thief leader gave a rebellious look at Dharkon. "Ready for this, Sora?"

Sora switched his Keyblade to brandished his Ultima Weapon and glared at the tentacled monster, "Yeah, Joker. Let's end this!"

Then, as the rest of the Phantom Thieves are fighting more Heartless; Sora, Joker, Yoshi, and Luigi charged at Dharkon by rushing towards the top of the skyscrapers to confront him head on. Dharkon started off by firing thousands of dark spikes at the four heroes. The heroes barely evaded the spikes, Sora guarded some of them, Joker slice down some with his dagger, Luigi used Thundaga to dispel some, and Yoshi used his shield to protect himself from the spikes. Both Bayonetta and Kirby fired their guns at the spikes and Dharkon's body.

Gaining enough strength, Yoshi then temporary sprouted white feathered wings in becoming his Super Dragon form. The green dinosaur cried out to call Sora's attention.

"Got it, Yoshi!" Sora nodded as he quickly rush to ride on the dinosaur. Yoshi flew up in the sky as Dharkon attempted to strike with his tentacles, but Sora used his Keyblade to hit and deflected Dharkon's attacks. Yoshi spews out fire from his mouth in hitting the abomination. Dharkon's sole eye fired a laser beam in about to hit the two, but Sora and Yoshi barely evaded the devastating beam. Joker has arrived to support by briefly flew with Arsène's black feathered wings on his back and fired countless Eiha by snapping his fingers, causing dark flames to hit Dharkon.

Dharkon then fired large dark energy spheres at his enemies, but Luigi used his Poltergust G-00 that it seriously sucked out all of the spheres and reflected them back at Dharkon to damage him. Bayonetta supported the green-clothed plumber by kicking some of the spheres at the monster for further damage. Dharkon's tentacles briefly disappeared as his eyeball is about to fall down to the ground. As the four heroes and two summons are about to strike back, Dharkon quickly recovered alongside his tentacles, and lets out an unholy screech in sending a dark shockwave and more spikes in hitting his opponents. Bayonetta and Kirby are recalled back from Sora for safety as the Summons disappeared.

"Not yet!" Sora cried out, that by drawing the power of his Ultima Weapon, the Keyblade wielder unleashed his Ultimate Form from the Ultima Weapon to transformed into a legendary sword with his clothing turn white. Now levitating, Sora unleashed swords in dispelling all of the spikes. Dharkon then fired another laser beam from his eye, but Sora used his Ultima Weapon blade to deflected the beam, after a brief struggle, Sora then pushed the energies into Dharkon in greatly damaging the eldritch beast.

This is their chance.

"Here comes our All-Out Attack!" Joker declared.

Then, the Phantom Thief, Sora, Yoshi, and Luigi leap upward and giving game faces towards the weakened Dharkon. The time has come for brutality indeed. The screen turned red with Dharkon's silhouette, as flashes of the four silhouetted heroes repeatedly hit Dharkon many times. Additionally, Sora also used his finisher from his Ultimate Form state in raining down swords and light columns while slashing at the abomination with his Ultima Weapon. Both Sora and Joker then pierce through Dharkon's eye body with their blades.

As both protagonists stand in triumph, Dharkon screamed out in the background as the chaotic monster exploded and disappeared. The remaining Heartless are slain by the Phantom Thieves.

"We did it!" Sora victoriously cheered.

xxxxx

In the aftermath of Dharkon and his forces are slain, the city of Shibuya is restored back to normal. In the busy streets where civilians are seen wandering back to their daily lives, Sora & his friends and the Phantom Thieves in their civilian appearances are seen interacting with another. They get acquainted more with each other, including what the Phantom Thieves do in their daily vigilante deeds by stealing corrupted hearts. This gives similarities of how Sora and his friends having themes relating to hearts.

"So you're from another area of Tokyo?" Makoto questioned the three visitors.

"To be frank, yeah. We just stop by and visit this place, only to figure of the monsters we help stopped." Sora answered, not to meddle with the affairs of revealing other Worlds.

"The city is so huge! It reminds a-me and my brother went to a similar city from another country!" Luigi commented on Shibuya in looking around the surroundings. That similar city he mentioned is New Donk City.

Hearing this from Luigi, Sora and his two friends are also reminded of New York City with Spider-Man.

"Glad you like it, dudes! Shibuya is a lot of sightseeing!" Ryuji grinned.

"And we have a green dinosaur standing out in the crowd." Yusuke calmly chuckled about Yoshi. Yoshi can turn in giving a blink of the remark.

"Oh, Inari!" Futaba responded by patting Yoshi's head. "I bet he adorable enough that he fought those monsters, including those wings he sprouted!"

"Say Sora, there's also some pics we like to show you!" Ann offered.

Then, Ann showed Sora and his two friends photos from her phone of the Phantom Thieves' fun times, one of which is their Hawaii school vacation. One picture showed a young Shogi woman Hifumi Togo and a foreigner who is an exchange student in Kosei High, that foreigner is a young man named Skyler Jones and the same main protagonist that is Code Vein. Another picture showed a foreign girl wearing a tall papaha hat named Mia Karnstein with Morgana on the streets. Another picture showed a Japanese young man named Yakumo Shinonome. Another picture showed a foreign young man named Louis, who he's seen with Haru.

"Nice friends you have there." Sora responded of seeing these pictures.

"Thank you, I have gotten to know one of them more." Haru politely commented about the picture between her and Louis.

"And you know what's something cool, other than Hifumi, these four friends of ours are vampires called Revenants that helped us during the Palace and Mementos missions." Ann added.

"Really?! That is so awesome!" Sora is giddy of whether he imagines meeting these Revenants.

"Vampires, huh? Hope they're not scary in drinking our a-bloods!" Luigi quivered a little, coming from his experiences of ghosts and Boos. Yoshi can somehow agree with the green-clothed plumber.

"Good news, they won't do that, so long as there's blood in other places that are not people." Makoto reassured.

"Thank goodness!" Luigi sighed in relief.

"Well, as much as we want to stay for a while, we have other important stuff going on in our hands." Sora announced to the Phantom Thieves.

"Whoa, a bummer that we just met and now that you guys are leaving." Ryuji remarked.

"Well, for what Sora and his companions have experiences with these creatures, I bet it's something important that they won't tell you, monkey." Morgana responded and gave his snide insult towards Ryuji.

"Shut up, cat!" Ryuji snapped at the black cat, leaving a few people chuckled at their banter.

"If it's that important, then we wish you the best of luck." Makoto gave her blessings to the Nintendo trio.

"Come back and visit some time!" Ann smiled.

"Take care, Sora. Until our paths cross again." Ren gave his farewell with a handshake.

"Same to you, Joker." Sora grinned in returning the favor.

And so, the two groups went on their separate ways. Sora, Luigi, and Yoshi are heading to their Gummi Ship. The time has come for the Nintendo trio to head to the Keyblade Graveyard.

In distance, five teenagers are seen on top of a skyscraper in one of the few witnesses of seeing the Gummi Ship take off. Their names are Neku, Shiki, Joshua, Beat, and Rhyme. They smiled in the skies of feeling Sora's light, wondering will they meet again.

xxxxx

The Velvet Room

The area then shifted back into Igor's personal area.

"Thus, that concludes the special teamwork between the Persona users and the Keyblade wielder." Igor smiled to himself. "It is nice that the boundaries between their perspectives come together for extinguishing their common foe and learning each other's bonds. Now, Sora and his friends are about to face their greatest battles for the fate of all hearts."

Then, Igor showed visions of the future for the final battles and events:

Sora, Yoshi, and Luigi fought thousands of Heartless, Nobodies, and Unversed; to the point they use the Spirit Train in cleaning them up.

Luigi using Emerald Zettaflare from his Save the Queen+ at Terra-Xehanort. But, a Demon Tide swallowed up Sora and his friends in bringing utmost despair.

Sora meeting a Chirithy in The Final World, and upon reconstructing his body, ventured to save his friends with the guidance of Kairi's light. Then, Sora is saving his friends from the Lich Heartless by using the Power of Waking, but Young Xehanort warned of misusing the ability. Back in the Keyblade Graveyard, thanks to the presence of Naminé, the Lingering Will is holding off Terra-Xehanort.

Sora, Yoshi, and Luigi fighting the Demon Tide. The rest of the Seven Guardians fight various enemies such as a Dark Inferno Heartless; alongside Galeem summoned by Organization XIII. Kirby is briefly summoned to fight Galeem. Sora riding on flying Keyblades to mow down Galeem that merged with a tornado-filled Demon Tide, with the assistance of Ephemer's spirit and Union χ. Although he didn't tell his name, Ephemer mentioned to Sora that he and his companions fought both Galeem and Dharkon back in their time. This is one of the crowning moments for Sora.

As more Heartless appeared, Miyamoto appeared in forming a wall of light for a pathway. This allows the heroes to reach their main enemies, while Yoshi and Luigi stay behind Miyamoto to clear out the Heartless.

The second Keyblade War against Organization XIII has properly started. One-by-one; Dark Riku, Xigbar, Luxord, Larxene, Marluxia, Saïx, Vanitas, and Terra-Xehanort are defeated. Both Xion and Terra are restored back to the light. Kairi gets kidnapped again, whoopee.

Sora, Mario, and Riku vs. Young Xehanort, Xemnas, and Ansem. While Ansem and Xemnas are given final sympathetic moments, Young Xehanort remained a malicious taunter in his last breath before returning back to his time.

Kairi is then killed by Master Xehanort. Why her, indeed. Sora and his friends attempted to avenge her, such as Mario attempted an Ultima only that Master Xehanort countered with Stopza. The χ-blade is finally forged and unlocked Kingdom Hearts, but the heroes are still not going to give up. Taking advantage of Xehanort's time powers, the heroes used him as a portal to trap himself within, while the Nintendo Trinity (Sora, Luigi, and Yoshi) followed Xehanort through.

Sora, Luigi, and Yoshi are now in Scala ad Caelum, a nexus which all other worlds spring and a former seat of power for all Keyblade wielders. The Nintendo Trinity first fought the twelve armored and masked Replica Xehanorts throughout the city. After defeating them, Master Xehanort absorbed their remains to armored himself up for the Nintendo Trinity to face their difficult battle. With Armored Master Xehanort distorting space to his will, the fighters thrash around the world; going from concrete land, underwater with Daybreak Town seen, and the skies.

At the rooftop of Scala ad Caelum; Sora w/Ultima Weapon Keyblade, Luigi, and Yoshi have their final confrontation against Master Xehanort with the χ-blade. In the background showed Kingdom Hearts looming in the dark skies. The final battle is just as hard, such as Master Xehanort steal Sora's light in forcing him to become his Rage Form and that Sora needs to reclaim his light to turn back to normal. Then, Master Xehanort used the full extent of Kingdom Hearts and the χ-blade to unleashed a beam that struck down Sora, but after the boy's two friends called out his name, Sora regained conscious. Together, the Nintendo Trinity unleashed their beam from Sora's Ultima Weapon more powerful in return at their enemy.

And finally; Master Xehanort is defeated as he surrendered the χ-blade to Sora before he and Eraqus departed to the afterlife. The heroes sealed Kingdom Hearts as the universe is restored back to normal. Then, the heroes are celebrating in Destiny Islands. But, upon Sora bringing back Kairi, and the couple shared a personal moment, Sora disappeared from the living realm due to the overuse of the Power of Waking.

Of course, there are future stories to tell: Back at the Keyblade Graveyard, Xigbar revealed himself to be Luxu and meeting the legendary Foretellers, with Bowser and Wario watching them in distance. Sora appearing in Shibuya. Riku's involvement. The appearance of Yozora in nightfall. A mysterious hooded figure, presumably the Master of Masters, is staring at the full moon and making a heart shape from his hands.

"I bid you farewell." Igor concludes with a smile.

With that said, the view is faded black.

xxxxx

Ford1114's A/N: So that's the team-up within my friend's fan-universe, culminating in fighting Dharkon. The one-shot is still a one-time deal in just being a guest collaboration.

Only the Phantom Thieves appear to keep the quality simple, much like the actual KH games in showing selective Disney characters in respective and not show every Disney character, though other characters are mentioned like Hifumi and the Code Vein characters seen in the Phantom Thieves' photos. The Thieves are seen as teenagers like in canon, due to being in a KH setting for alternate versions (alongside the Code Vein cameos) and drawing general audiences.

Anyway, that's all I have to say.