So, I decided to rewrite this. It just didn't really sit right with me. Also, I've been wanting Greninja to use a special Z-Crystal after reading Epicocity's Alolan Trilogy. It was just so cool! So, big thank you for giving me inspiration!

And don't worry, I'll still add Serena at the end. But I hope you guys enjoy this new version of- The Return of Greninja: United!

This time, it mostly takes place before Ultra Adventures start. And, Disclaimer: I do not own Pokemon!

[Alkala Island- few months previously]

Ash rode along on the back of his Stoutland, Pikachu perched on his shoulder. After that treasure hunt with the rest of the class, he wanted to do a little of exploring of his own. He had also asked Lana for directions to the cave where she had found the Z-Ring stone and was now heading there to see if he could find anything interesting.

"That should be it, right buddy?" asked Ash, pointing to the cave that they were approaching.

"Pi-ka!" agreed Pikachu, his tail swishing slightly in excitement.

"Alright, Stoutland, take us in!" He nudged the Big-Hearted Pokemon forward, and it walked into the cave. As soon as they walked through, the Stoutland started sniffing the ground, as if it was trying to find something.

As they made their way deeper into the cave, Ash happened to glance at the right side of the cave wall, where he saw several deep scratches in the wall. "That must've been where Lana found her Z-Ring, right buddy?" said Ash, pointing to the wall. Pikachu hopped off for a few seconds before confirming it.

Suddenly, Stoutland darted towards the left side of the cave, a little ways away from the scratches and sniffed a small spot before starting to dig. "What is it?" asked Ash.

When Stoutland finally stopped, it stepped back, giving a small bark of triumph. Ash slid off of it's back and bent down, before giving a shocked gasp...

()

"Where's Ash?" asked Mallow as they stepped outside.

"I think he went to go exploring," said Sophocoles, "He took a Stoutland with him."

"Well, let's hope he gets back soon," said Kiawe as their Pokemon- including Ash's Rowlet, Litten, and Rockruff- rushed around the Pokemon Center where they were staying, "Class will be starting in a bit."

"Hey guys!"

Everyone turned as Ash and Pikachu and their Stoutland came running up the trail. "Where were you Ash?" said Mallow, a slight scolding tone in her voice.

"Treasure hunting," he replied. "Did you find anything?" asked Lillie, picking up Snowy.

"Let me put up Stoutland first." Everyone followed Ash to the Stoutland stables, where Ash unsaddled and fed the dog-like Pokemon. As the Stoutland started to eat, Sophocoles said, "Well? Don't keep us in suspense! Did you find anything?"

Ash nodded and dug into his pocket for a bit, finally pulling out something. Everyone's eyes went wide in shock.

Ash held a Z-Crystal in his right hand, one they hadn't seen before. It was blue and red, and the symbol in the center was a dark gray bold X with a small circle in the middle of it. "Where'd you find it?" finally asked Lana and Kiawe.

"Same cave where you found your Z-Ring Stone," Ash said, looking at Lana.

"If you had found that during our class yesterday," said Kiawe, "You probably would've won the second round."

"I wonder what kind of Z-Crystal it is?" said Sophocoles, as Ash held it up to the dim light of the stable.

"Well," said Lillie, "It's blue, so that suggests that it could be a Water-type Pokemon."

"Yeah, but it's also red," said Kiawe, "That means it could be a fire type! But who ever heard of a Pokemon that's a Water-type and a Fire-type Pokemon?"

Both Lillie- and Ash- said at the same time, "I have."

"Really?" said Sophocoles skeptically.

*A Pokemon that is a Water-type and a Fire-type?* said Rotom in amazement, *The possibility of that being real is at least 28 percent true!*

"Then I don't think you're Pokedex has been updated enough, although I don't think many people know about him," Ash directed at the Rotomdex. Then he turned to the group and said, "When I was traveling in the Kalos region," he explained, "Me and my friends met the Mythical Steam Pokemon, Volcanion. He really didn't like us at first."

"Pika-pika," agreed Pikachu.

"You've met Volcanion?" Lillie said in amazement.

"Yeah." Ash said, "He and the rest of the Pokemon that were with him finally trusted us after we rescued one of the Pokemon that lived with them. It was a pretty crazy adventure, but I've had those before."

"So you've told us," said Kiawe, chuckling slightly.

"Alola!" The class turned to see Professor Kukui and Kahuna Olivia standing at the entrance to the stable. "Alola!" the class said in return.

'Where exactly have you been, Ash?" asked Kukui, "You weren't in bed this morning."

"Treasure hunting. Look what I found in a cave!" Ash showed them the Z-Crystal.

"I've never seen that kind of Z-Crystal before," said Olivia, "Incredible."

"I have heard of Z-Crystals that only work with certain kinds of Pokemon," said Kukui, "Ash, I think you may have found one of those kinds of Z-Crystals."

"So, which Pokemon is it for?" asked Lillie as Ash put it down so that the rest of his Pokemon could see it.

"I don't know," said Kukui, "How about you keep a hand on that until we know what kind of Pokemon that's for."

"Right." said Ash. As he looked at the Z-Crystal, he looked at the small symbol inside and felt a small sensation of deja-vu. Had he seen this symbol before?

Suddenly, the scene shifted. Ash suddenly felt like he was sitting in water, with more water around him. Voices and Pokemon called out, ones that he recognized.

Alain and his Mega-Charizard X...

Sawyer and his Sceptile...

Then, he heard the footsteps, walking away from him. He looked up, recognizing the frog-like Pokemon that was walking away from him. He quickly stood up, trying to yell, but with no voice coming out of his mouth. As soon as he got close, the Pokemon dissolved into water and he stopped, his cap falling off of his head.

As a tear streamed down his cheek and splashed into the water that swirled around his feet, a funnel of water suddenly sprang up. He shielded his eyes from the water, and when it cleared, he lowered his arms, recognizing the Pokemon in front of him.

It was a Greninja, but resembling Ash. The crest on top of his head was red, and the fins that poked out behind his head were black. His glowing red eyes had small white triangles above them, and several messy looking spikes with red stripes jutted out behind them. His chest was a circle with a dark blue point jutting down the middle of it, with another white point at the bottom of the circle. And across his back was a massive shurikan made of glowing and rippling water.

Ash gave a sigh of relief, rushing forward and hugging the familiar Pokemon, whose arms wrapped around his trainer. For a while, Ash and Greninja stood there, hugging each other tightly.

Then, Greninja fell to his knees, nearly dragging Ash down with him.

Ash was slightly relieved to hear his voice as he asked, "Greninja, what's wrong?"

He suddenly became aware of a warmth on his left wrist, and when he looked, his Z-Ring was glowing brightly, with the mysterious Z-Crystal that he had found on Alkala Island shining with an unetheral light.

Ash turned and looked back at Greninja, wanting to ask what was happening, but a voice stopped him. Greninja looked up at him, and said, in a voice that resonated around his head, "Ash... Help me!"

[Present time- two days after returning from Kanto]

Ash sat up, a scream nearly ripping out of his throat. He looked around the loft, breathing heavily from his nightmare. Pikachu was still asleep, currently resting on top of Lycanroc, who was curled up at the foot of Ash's bed. Litten was sleeping on the small chair next to Rotomdex, and Rowlet, as usual, was sleeping in Ash's backpack.

Ash finally managed to slow his breathing, then, he walked over to his backpack, careful not to disturb the Quill Pokemon that slept inside of it. He pulled out of the side pocket a small bag where he kept all of his Z-Crystals. He finally pulled out the blue and red crystal, looking at it and finally asking a silent question to the one Pokemon that couldn't hear him currently. "Greninja?"

()

As everyone ate breakfast- or in Rotom's case, watched TV- Ash didn't exactly eat his breakfast with the usual vigor that he had. He was too busy thinking about his dream last night. Or maybe it was a vision. Last time he had a dream like that was when he first met Azelf.

Feeling like someone was staring at him, he looked up to see Professor Kukui looking at him with a slight worry in his eyes. "Are you all right Ash?" asked the professor.

"Just thinking," replied the trainer. All of his Pokemon looked up at that. Even Rotom looked up from the TV screen, where he was watching his usual detective program. Whenever Ash said he was thinking, that usually meant that something was really bothering him.

"What is it?" finally asked Kukui.

"A dream I had last night," said Ash. Turning to Pikachu, he asked his partner, "Hey, Pikachu, you remember Greninja, right?"

"Pika-Pika!" confirmed Pikachu.

Ash dug in his pockets for a second and pulled out the mysterious Z-Crystal. "I think I know what kind of Pokemon this is for now."

"Really?" said Kukui, "Then I'm guessing it's not Volcanion, right?"

Ash nodded. "I think it's for Greninja."

*But Greninja is not a dual Water and Fire type,* said Rotom in confusion, *And with the Z-Crystal being blue and red, that suggests that the Pokemon has to be a Water/Fire type.*

"That Z-Crystal has been on everyone's minds for a while, Ash," said Kukui, "How about at school you say why you think it could be for a Greninja, alright?"

Ash nodded, then went back to eating breakfast, but every once in a while, his vision strayed to the crystal and his thoughts back to his dream. Why did he have that dream?

()

[Pokemon School]

"Class," Professor Kukui announced, "Ash may have an idea as to what kind of Pokemon that the Z-Crystal he found responds to." Everyone looked at Ash as he said, "I think the Z-Crystal responds to Greninja."

"But, Greninja's aren't a Water and Fire type Pokemon," said Lillie.

"Why do you think it's a Greninja, Ash?" asked Kiawe, looking confused.

"Well, two reasons," said Ash, "One is that I had a Greninja before. He was one of my most powerful Pokemon in my Kalos team. We had this really cool ability called a Bond Phenomenon. Professor Sycamore said that it was a rare evolution that happened every three-hundred years or so. Whenever we triggered it, it was like we became one. During the finals of the Kalos League, we summoned this huge firey Water Shurikan. Now that I think about it, that could have been a Z-Move."

"Wow." said Sophocoles after a few moments, "You are just full of surprises, aren't you?"

"And, what about the second reason?" asked Professor Kukui, "Would that have to do with why you were acting a bit strange this morning?"

Ash nodded. Then, he explained the dream that he had had the night before.

Sophocoles still seemed a little bit skeptical. "Just because you had a dream about one of your Pokemon and that Z-Crystal glowing doesn't mean that your Greninja is the one that can use it. Greninja's are Water and Dark type Pokemon. Right, Rotom?"

*Correct!* said the floating Pokedex. It projected Greninja's profile on it's screen and quoted, *Greninja. The Ninja Pokemon, and the final evolved form of Froakie. A Water and Dark type. Greninja can compress water into sharp-edged throwing stars. With the grace of a ninja, it slips in and out of sight to attack from the shadows.* After it's screen turned normal again, it said, *Besides, basing a theory on a dream is extremely illogical.*

Ash appeared to be thinking for a few seconds before saying, "When I was traveling in Sinnoh, I had a dream about the Pokemon Azelf choosing me. And a while later, me and Azelf worked together to help calm down Dialga and Palkia. Besides, with me, any dream like this usually comes true... What?" He happened to notice everyone looking at him strangely. "Okay." said Mallow, "Maybe Ash having a dream about a Pokemon that he has a bond with and a Z-Crystal glowing could come true."

"I'm thinking that maybe we should talk to Hala before we come up with anything real definitive yet." said Kukui, "We don't really have a lesson today either, so we could go right now."

"If it'll make you guys feel better," said Ash, shrugging slightly and standing up.

And with that, the class headed for Iki Town to talk to Kahuna Hala.

Meanwhile, across the ocean, strange things and evil was at work...

()

Two small green figures watched from the trees in horror and anger as a Pokemon was dragged roughly into a truck. As the truck drove away, one of them turned to the other. "Do you know where they may be headed?" it asked. It almost resembled a green blob, with one white eye and a red crystal in its middle.

"I thought I heard something about the Alola Region," replied its companion. It resembled it, except the crystal in it's middle was blue. "Something about Team Skull and a man named Faba."

"Didn't Greninja say something about his trainer being in that region?" said the red crystaled one.

The blue crystaled one nodded and told it's companion, "Squishy, I believe we should send word to Tapu Koko. He did tell us that he chose Ash to help deal with the coming storm, correct?"

"Which means that Tapu Koko could tell Ash that Greninja is in danger!" realized Squishy. He quickly turned to one of the Zygarde Cells next to him and said, "We must speak with Tapu Koko! Quickly!"

The Cell gave a small shudder and after a bit, a projected image of the entrance of the Ruins of Conflict appeared in front of them. After a few minutes, a familiar yellow, orange and black Pokemon appeared in front of them. "You called for me?" asked the guardian deity.

"You must pass a message to your champion," said Squishy, "His partner is heading to his region. He might have already sent a message to him, but you must confirm it! Whatever Team Flare and Team Skull and Faba have in store for Greninja, it may not be good!"

Tapu Koko nodded and its image faded. "Now what?" asked Squishy's friend.

"Now, Zygarde," said Squishy, "We follow the truck and see where it will head. Perhaps we can get Greninja rescued before they reach the port."

"And how exactly will we do that?" asked Zygarde.

"We call in backup. We are close to Lumious City. I will try to find Bonnie and her brother. Can you follow them and find out where they are headed?"

"I can." Instantly, the two Pokemon summoned more Cells, going into their 10% forms before bounding into the forest, one headed after the trucks, the other towards the nearby city.

There was little time left.

Yeah, I am really liking the start of this story better than the other one. We're not doing the rescue just yet, but it will be coming soon.

And don't worry, everyone! Ash will rescue Greninja! Until next time!