Author's Note: I've been reading the Pokemon Adventures Manga for the first time ever since I was 9-10 years old and I can proudly say that, even after all of this time, it is still great! Although, my only real concern for the manga is that it seems to be losing some popularity and I can't really keep up with the most recent volumes. Anyways, as a guy who just loves Ultraman and Pokemon ever since I was a kid, I thought it would be a good idea for a crossover fanfic between the two series. I mean, there is barely any Pokespe crossover fanfics and Ultraman doesn't have a lot of crossover fanfics when compared to Kamen Rider and Super Sentai. Anyways, enough with me rambling. Time for this story to begin.

Land of Light…

Inside of the main command tower of the Inter Galactic Defense Force, Ultraseven was right now staring out of its windows as he looked at the green sky from his position. Right now, he was thinking about an Earth that he had once visited sometime after Ultraman 80 left Earth to help him and the other Ultra Brothers, alongside with any other Ultras, patrol the universe and protect it.

"I wonder how much time has passed ever since I visited that world…." Seven thought to himself, before a voice called out to him.

"Finally! I've been looking all over for you father!" The voice cried out, causing Seven to bring him out of his thoughts and look behind him.

Behind him was no other than his son, Ultraman Zero. It had been a few weeks ever since Zero returned from Ultraman Geed's universe and the great defeat of Ultraman Belial. Words couldn't describe how relieved he was to find out that Belial had finally been defeated for good and was sealed away in a dimension forever. Granted, while he had to admit that sealing Belial in a dimension forever was a bit too much, it was necessary to make sure a dark Ultra, like Belial, had finally been taken out for good this time. Plus, from what Zero told him, Ultraman Geed, who was Belial's own son/clone, was able to purge the darkness out of his father and expel Alien Reiblood's influence on him for good and Belial just accepted that he was gonna stay there forever.

"It's good to see you, my son." Seven said. "How were you on Geeds Earth, aside from your Ultra Zero Bracelet being broken?"

"It was fine." Zero replied, shrugging. "Aside from feeling weaker and having to only rely on my Beyond form, I was able to last on that Earth for a while until I was able to get my bracelet fixed."

"Good." Seven said, in a bit of relief. "Right now, we need you to go on another mission."

"Another one already?" Zero asked, before signing a bit. "Of course, we can't catch a break. Can we?"

"I'm afraid so." Seven replied. "This mission involves you going to a new Earth that none of us Ultras, except for me, have been to before."

"Really? What's it like?" Zero asked, crossing his arms.

"This Earth doesn't have any Ultra Warriors protecting it, nor are any Ultras who exist in it." Seven answered. "It also has creatures called Pokemon living on it alongside with the humans of that Earth."

"Pokemon, huh?" Zero mused. "How'd you come across that world?"

"It all started when I was chasing down some alien bandits who fled to another universe and I was able to track them down to that universe and confront them on that Earth." Seven replied. "Thankfully, I was able to take them down before they could do any harm to that world. While on that planet, I discovered the existence of Pokemon and did some research on them while staying there for a while."

"Huh. Not a bad story." Zero remarked. "Why do you need me to go to that Earth?"

"We are not sure, but some unknown darkness is currently hiding in that world and it feels familiar. We needed someone to investigate that Earth and we decided to send you there, Zero." Ultraseven said, his tone growing serious.

"Got it. You can count on me to make sure that Earth is okay." Zero said, turning around to exit the tower.

"Zero, wait!" Seven called out to his son, causing him to turn around. "You'll need to know where that universe with the Earth is first."

Ultraseven used his hand to summon a small ball of light and thrusted it towards Zero, who quickly reacted to it and raised his arm, having the Ultra Zero Bracelet, and allowing the small ball of light to enter his bracelet. Zero looked at the bracelet in satisfaction as he saw it glow for a second before returning to normal.

"Thanks father." Zero said. "Wish me good luck."

After Zero said that, he soon exited the tower and headed outside. Once outside of the tower, Zero faced the green sky and leaped up into the air, letting out a grunt as he flew out of the planet's surface, as Ultraseven saw it all from the tower he was in.

"Good luck my son." Seven thought to himself.

Space…

Once outside the Land of Light and in the darkness of space, where a bunch of stars were at, Ultraman Zero started to fly through space as he touched his Ultra Zero Bracelet and soon, turned into his Ultimate Zero form as the Ultimate Aegis formed around his body. Using his Ultimate form's power, Zero created a portal in front of him and soon flew into it, with the portal closing after he went into it. Inside of the portal, Zero flew faster as he looked at the gem on his arm blade and saw the small ball of light that his father inserted into his bracelet come out of the gem and flew in front of Zero, as if it was guiding him.

"I hope you're ready, new Earth! Ultraman Zero is on his way!" Zero declared, still flying inside of the portal as it was just one huge crimson tunnel. "I'll blow away whatever darkness you have like a black hole!"

Inside of the Light Stone…

Black honestly had no idea how long he was in the light stone, since it was so quiet and dark. What's even worse is that he felt completely lifeless. His body floated in the air, among the abyss of darkness that surrounded him. There was nothing to hear, smell or taste. His eyes felt blinded from the black and his fingers grasped nothing but air.

He then remembered how he was sucked into the Light Stone and how he admitted to White, that he promised to take off his jacket to show the media the shirt he had on him, which had the BW Agency logo, and shout out the advertisement for the BW Agency, when he'd earn the right to challenge the Elite Four. However, he wondered if he satisfied her by revealing it. However, now he was stuck here, away from White and the rest of his friends and his mom.

"White…." Black thought to himself. "I miss you so much."

Space…

A portal opened out in the middle of space and out coming from it was Ultraman Zero, in his Ultimate Zero form. The portal closed behind Zero as his Ultimate Aegis armor soon turned back into his Ultra Zero Bracelet, reverting Zero back to his base form while the Ultra Warrior looked to see, in front of him, was the Earth of this universe he had just arrived to.

"So, this must be the Earth father was talking about." Zero thought to himself. "Looks like every other Earth that I have visited in the past."

Zero soon flew down to Earth, passing by its atmosphere as he started to see the ocean in front of him while he was flying down. Just then, he spotted something fast below as it zipped above the ocean and in the right direction Zero was hovering in.

"Now, what could that be?" Zero wondered, before he decided to go after the thing that zipped past his right direction.

Wasting no time, Zero flew after the thing that zipped past his right direction and flew down just to the level that is not so high above the ocean, but not in it at all. When catching up to the thing, Zero saw that it was some kind of white ball that was somehow floating and flying in the air. However, that didn't confuse the son of Ultraseven as he sensed that there was someone trapped in the white ball, causing him to be a bit caught off guard.

"Who is stuck in there?!" Zero thought to himself, before deciding to save the unknown person inside of the white ball.

A few minutes later, when Zero finally had reached it, Zero grabbed the white ball and soon focused his energy into the white ball. A few seconds later, Zero's body completely disappeared, leaving the white ball the only thing hovering above the ocean as it suddenly glowed blue, before it headed off to the nearest piece of land it could find.

Inside of the Light Stone…

Black felt the Light Stone was suddenly grabbed onto by someone, but had no idea who it was. Could it be White? Cheren? Bianca? Maybe his mom? Maybe one of the gym leaders or Alder? However, Black feared that maybe it might have been Ghestis or Team Plasma who found him.

Unfortunately, it wouldn't be any of them as Black saw some sort of blue light coming his way and was also in the Light Stone too, causing him to be confused and worried of what that thing could be. As the light grew closer and closer to him, Black had the urge to scream, but couldn't as he was too weak to do anything, before, much to his bafflement, he heard the light speak.

"Oi! Don't worry. I'm saving you." The light said, while soon engulfed him, causing Black to faint as he felt his body go through some strange changes.

A few minutes later, outside…

Black blinked a few times as he slowly woke up, groaning. He looked around his surroundings and realized that he was actually back outside, causing him to be shocked and relieved.

"I… I am back?!" Black asked, looking around his surroundings, before he broke into a massive grin. "I'm back! I can't believe this!"

"Well, you can now believe it." Zero's voice remarked, causing Black to be caught off guard as he looked around for the voice.

"Who said that?!" Black cried out, looking frantically for the voice. "Show yourself!"

"Relax. I'm not gonna hurt you." Zero assured. "By the way, I'm Zero. Ultraman Zero."

"... Are you some kind of Pokemon that can somehow talk?" Black asked, clearly confused at what an Ultraman is.

"What? No. I am not even from this universe." Zero replied, causing Black to suddenly gawk.

"Wait… so the multiverse theory is actually real?!" Black asked, remembering how he read a theory about there being alternate universes.

"Pretty much." Zero answered, smirking a bit at Black's reaction. "So, you wanna tell me how you ended up in that white ball in the first place?"

"Well, it's a long story…" Black chuckled nervously.

Black explained on how he became a Pokemon trainer and got his Pokedex, how he met White and was kinda forced to work for her company, the BW Agency, how he and White encountered Team Plasma and fought them, how he got all of his gym badges, how he took part in the Pokemon league, how he awakened Reshiram from the Light Stone, and how he got sucked into it. After explaining his history, Zero was a bit impressed with Black's adventures.

"Not bad, kid." Zero said. "That must have been so much for you to handle."

"Thanks, but I've got one question…" Black looked around for Zero. "Where the heck are you?"

"I'm in your body." Zero answered, causing Black's eyes to widen and his jaw to drop to the ground. "Don't worry. I just bonded with you as my human host. That's what we Ultras do if we see a human badly hurt. Now, while you weren't hurt, your body was really weak while you were inside of that white ball. Thankfully, I was able to get you out of there."

"Okay…" Black said, awkwardly. "By the way, what's an Ultra?"

Zero went on to explain who Ultra Warriors are and how they came to be. Zero said how, in his universe, the Ultras used to look like humans until their sun was nearing the end of its life. In a move to save their race, the Ultras' smartest scientists came together to create an artificial sun called the Plasma Spark. It worked and the light didn't just save the Ultras, it also changed them completely, turning them into giants of light before they decided to fight for peace and went around the universe, protecting all sorts of planets and civilizations.

"Wow… that is… I have no words other than that sounds really amazing." Black said in awe, after Zero was done explaining the history of the Ultras in his universe. "So, what are you doing here on my Earth?"

"I came here to investigate some sort of darkness that is hiding out on this Earth." Zero answered, his tone turning serious. "I don't know what it is, but I'm sensing that it's all the way out here."

"Really?" Black asked. "Can you just go stop it by yourself?"

"About that, I sorta need a human host, which is you, for me to travel on this Earth since I can maintain my true form for 3 minutes on this planet." Zero, sheepishly, said. "So, I hate to break it to you, but I am gonna need you to be my human host for a while."

"Are you kidding me?!" Black cried out. "I just wanted to go finally see my friends and mom!"

"Sorry kid. But you're stuck with me until I deal with this darkness." Zero said. "Don't worry. Once this is all over, you can get back to your family and friends."

"Okay. Let's just get this over with." Black signed. "By the way, if you don't know who I am, I'm Black."

"Black, huh? Don't worry. You have my word." Zero said.

Soon, Black walked off as he, with Zero, tried to find some sort of city or town to stay in for a while so Zero could deal with this darkness. Unbeknownst to them, some shadowy figure was spying on them from the air, looking down at Black. While the shadowy figure couldn't see Ultraman Zero, he could sense his presence, as he just let out a growl.

"So… you have ended up here too, Ultraman Zero. Hmph, doesn't matter. You alone won't stop us." The shadowy figure scoffed before leaving.

Author's Note: This takes place after the finale of Ultraman Geed and after the events of the Black and White Arc of Pokespe. Hope so I did a good job of writing the first chapter of this Fanfic. Feel free to critique me in the reviews, but in a nice way. Oh, and I did try to do a story like this, but I deleted it, feeling dissatisfied with it. Anyways, see you all next time.