Disclaimer: I do not own the characters of Pokémon, Digimon, or Naruto. All rights go to their respective companies.

Pokémon! Sun. And. Moon!

You know you've come so far, so why stop right where you are?

New challenges coming your way, so move out of the way, let's go, go, go!

Gym Leaders, Rivals, Elite Four, the Champion awaits! Let's go out and play!

Pokémon! Sun and Moon! You know you're in it to win it, so why stop where you are?!

So stand up and fight! Team Skull, go away! We're here to save the day!

New friends and new adventures await, come on, let's play!

Sun and Moon! In a battle of Day and Night! Whoa oh! Let's go out during the day and night! And let's play!

Get your game on! It's time to have some fun!

You know you're. In it to win it. So stay strong and! Get in the game!

The Sun shines brightly now! The Moon's come out to play! It's a new adventure, hey, hey! Pokémon!

Alola has many adventures waiting for you now! C'mon! Let's go get them now!

You can catch 'em all! Pokémon Sun and Moon!

Yamato's Voice

Fusion Confusion!

As our heroes keep on travelling to the Mahalo City Gym, there's a big message on Jumbotron! What could be happening?

"Ladies and gentlemen, it's time to announce the Lineup for this year's annual All-Star Concert and Tournament! On our starting bracket, we have Katy Perry and Britney Spears going at it for a battle of musical talent in a duet showdown! Metro Station and Good Charlotte will open up the ceremonies for the Concert! Demi Lovato is appearing as a singer singing her cover of I Love Rock 'N Roll by Joan Jett and the Blackhearts! Speaking of Joan Jett, she'll also be performing with Miley Cyrus in an all-star concert for Joan Jett's recent anniversary album and the albums she came out with to begin her debut! Bowling For Soup will be doing a duet with The Dollyrots singing their duet rendition of the classic song High School Never Ends! Metro Station will be performing a rendition of Love and War and Good Charlotte will be singing their rendition of Shake It by Metro Station! Our guest performers will feature the Cast of RENT singing a reunion special performance of Seasons of Love with Stevie Wonder joining their cast for the song! The Lion King Musical Casts from Japan and the US will be performing both of their renditions of I Just Can't Wait To Be King! Ladies and gentlemen, this is going to be a concert to remember! Hold onto your seats because the Pokémon World Tournament will be hosting a Tournament for Trainers, Gym Leaders, Elite Four members and Champions to all perform in! Are you ready for THE Party of the Century?! Tickets are on sale now!" An announcer's voice shouted.

Yamato nodded as he held his tickets in his hand. The entire group had gotten free tickets in advance due to saving the World from Team Tiki. Yamato began to stare into space as he remembered his battle with Olmec and Austin alongside Ash and Paul.

Begin Flashback

"Go Sylveon! Use Hyper Voice!" Yamato shouted, tossing his Poké Ball to reveal a Sylveon.

"Absol! Meowth! Get in there!" The two Grunts shouted as they sent out their Pokémon.

"Litten! Help us out!" Ash shouted.

"Popplio! Stand by for battle!" Paul exclaimed.

"Rowlet, come out and help us!" Serena shouted, sending out her Rowlet.

"Go Exeggutor! Crush these low-lifes!" Olmec shouted, tossing an Ultra Ball.

"Sandslash! Get in there as well!" Austin snarled, sending out a Steel and Ice-type Sandslash.

"Whoa, who's that Pokémon?" Ash asked, taking out his PokéDex.

"Sandslash, Alola Form and the evolved form of Sandshrew, Alola Form. It is the Mouse Pokémon and 3 feet and 11 inches tall and weighs 121.3 pounds. The Alolan Sandslash live on the snowy mountains of Alola and evolve from their pre-evolutions, the Alolan Sandshrew. These Pokémon are known to be rather heavy and have spiny backs that are coated in ice. These spines are very large and sharp and Alolan Sandslash hide in the snow when strong enemies appear leaving only their needles exposed and ready for business. The weight of their spines makes them much heavier than normal Sandslash and as a result slower than normal Sandslash. Yet in snow fields and ice, they move by creating a path with their claws so they can move faster. The sprays of snow they kick up are so beautiful that many photographers head for the snowy peaks to capture the moment. However, because Alolan Sandslash live so high up in the mountains, there is a great risk of becoming stranded, so it's prohibited to climb the mountains Alolan Sandslash live on without permission." The PokéDex said.

"Whoa, so that's a form of Sandslash. That Meowth must be a rare form of Meowth." Ash said, looking at the Meowth.

"Yeah, Ash, that's an Alolan Meowth and it's a Dark-type so be careful." Paul replied, looking at the Meowth.

"Sylveon, use Hyper Voice!" Yamato shouted, looking at his Sylveon, who nodded in response.

"Popplio use Disarming Voice on the Meowth!" Paul shouted.

"Rowlet, use Leafage on the Absol!" Serena cried.

"Litten, use Flamethrower on the Sandslash! Let's go!" Ash cried out, pressing the button crystal on his Z-Bracelet.

"Greninja! Ja!" Greninja exclaimed, popping out of its Poké Ball.

"Oh no! How'd Greninja escape?!" Clemont exclaimed.

"It must've sensed danger and used the tactics it used to beat Team Flare to fuse with Ash while Ash wasn't looking." Brock said, looking at Greninja and then at Ash.

Yamato blinked in confusion as the water whirlpool swirled around Ash forming the fusion base for Ash-Greninja. The whole group was shocked and their mouths were open, agape with confusion of how Greninja escaped.

"This could only mean one thing. Greninja is kind of an escape artist like Oshawott. Oshawott tends to get out of its ball a lot." Cilan deduced, looking at the others in the group.

Suddenly, Sandslash fell to the ground at the hands of a powerful Night Slash. Absol and Meowth were both shot down by Water Shuriken and Exeggutor was suddenly cut down to size by a powerful Aerial Ace. Ash blinked in surprise and his mouth hung open and agape because of the intensity and extreme power Greninja had exhibited. Suddenly, a blinding light enveloped Ash and pulled his body towards Greninja's and the two began to fuse.

"Ja? Huh? What in the name of Arceus is going on? Ja? Greninja?! What just happened?!" Ash cried out.

"Oh my Arceus! Greninja and Ash fused together and now they're stuck in the same body! They actually merged bodies! How?!" Gary Oak exclaimed.

"Don't worry. As the former head of Team Flare, which has since been disbanded, the crew at Lysandre Labs are going to do everything in their power to undo the fusion. We might not be successful. This could potentially by a permanent change. There's a chance that their bond has grown so tight that Greninja has chosen to merge himself with Ash and fuse his heart, body and soul with his own. We'll do everything in our power to remove the effects of this fusion." Lysandre said, walking up to Ash.

"Ja. Okay. Ninja, Greninja. Okay." Ash and Greninja tried to say at the same time.

"It's alright. I can actually understand why the both of you would try to speak at the same time. Normally, I would ask you to speak one at a time but seeing as though two people have become one, I notice that this is not possible." Lysandre said, chuckling.

"Ninja, ninja." The Greninja part of the fusion said.

"Okay." Ash's half of the fusion said.

"Ninja, Ninja, Ninja, Greninja?" The Greninja half of the Fusion asked.

"What'll happen if we're stuck together like this?" Ash's half of the fusion asked.

"Well, in that case, I'll build a device that will allow Greninja to use human speech so we can understand both of you." Lysandre said, chuckling.

"Ninja." Greninja's half of the Fusion said.

"Okay." Ash's half of the fusion replied.

"Now, let's get to work on removing the fusion's effects, for starters." Lysandre chuckled, smiling.

End Flashback

Yamato smiled even though the two were stuck together for life. Even so, the device allowed the crew to understand the fusion perfectly. Paul understood that the marriage between the fusion Ash and the two of them and Serena would normally been seen as Poképhilia but Ash understood perfectly. Paul and Ash/Greninja had obtained a License that would exempt them from being charged with Poképhilia. As long as that license was in hand, Ash was legally allowed to be part Pokémon and part Human and be married to his husband and wife. It wasn't long before Yamato noticed a change in Taichi's behavior. Signs were showing of him taking on Pokémon that Takato wouldn't usually be able to handle. Takato developed strength like never before. A new, much darker form of Takato took shape and Rika took on a similar form. The Latios, Takato, knew his body would need quite some time to adjust. It was plainly obvious that Takato was adapting into a Dark-type and Dragon-type. However, Takato, nonetheless was able to keep his Psychic type moves and powers. Latias underwent the same changes and Rika cried out lightly in slight pain but she was able to survive it so far. Rika was even able to keep her Psychic moves and powers. Latios and Latias gained sharp fangs and sharper claws. Yamato stared in awe at Rika, looking at her new darker appearance. Her benevolent nature remained intact. Takato's benevolent nature remained as well. But with their new abilities came with new challenges as well. Rika was often clumsy and she often tripped and fell. Takato had become more clumsy and he often tripped and fell, but he tripped and fell more often. It was obvious to Yamato that he'd need to train Takato and Rika to regain their land-legs. Their sea-legs had taken over and now they were struggling to use their land-legs.

What has caused this mysterious new change in both Rika and Takato? Could this be the work of a legendary Pokémon? Could the legendary Moon Pokémon, Lunala be at work here? If Lunala is at work behind the scenes, then she has some explaining to do, or does she? The answer to come... As the journey continues!