First crossover I've ever done so hopefully I manage to balance it between the two sides.
Enjoy

Chapter 1
The Charizard Guild was quiet, several Rescue and Exploration Teams had long gone to bed. Only a young yellow, mous-like pokemon with red cheeks and a lightning bolt-shaped tail, a Pikachu, stood awake in the room with his team.
"Why do I feel strange?" The Pikachu, Mathew, asked himself as he looked at the full moon in the sky, why do I keep having those weird dreams?
Mathew sighed and went over to his bed. "I should get some sleep" he said as he looked at the sundial on the wall. "Doduo will be up soon to give the wake-up call."
With that Mathew closed his eyes and drifted off to sleep.
“DO-DO-DO!” a loud call came from the doorway, causing a light grey bird with a white spot on its chest and it face, as well as a small dark grey crown on its head, a Starly, to fall off her perch on a vine and onto the ground with a loud ‘Thud’.
“Ugh…” the Starly, Star, groaned as she stood up “Remind me to tell him that next time if he’s going to wake us up to be a bit quieter so we can get some sleep.”
“We should get into the main room” A small light-blue penguin pokemon with a white face and a dark blue 'cape', a Piplup, named Alice said grabbing three scarves from the wall, a shining badge with a silver center was clipped to each one.
Soon several teams had gathered in the main room, talking about several missions and news they had heard about.
The chatter stopped as a bipeadal, orange dragon pokemon with dark aqua wing membranes, a Charizard, the guildmaster came out of a room, followed by a dinosaur like pokemon witha leaf on its head, known as a Bayleaf and a brown owl-like one, a Noctowl. These were the Charizard's assistants and friends.
Everyone’s attention turned to Charizard as he began to speak. “As of yesterday we have received rumors of strange things happening in several Mystery Dungeons and other towns and cities.”
Several teams began to murmur about the news. Some in panic, others in confusion.
“Do not be alarmed by this” Charizard continued “These are just rumors and there is no evidence yet that they are true.”
This caused the apprentices to calm down, some were still suspicious though.
“And that concludes today’s announcements!” Bayleaf exclaimed in her usual cheerful tone. “Now get to work” Noctowl said “those missions won’t pick themselves you know.”
The teams split up; some going to do there jobs in the guild, others going to the boards, into town, or on a mission.
Mathew went over to one of the several mission boards in the upper room of the guild. He had gone back to his team’s room to grab something, their bag. He saw his team members over by the board on the far left of the room, talking to another team, Team Solar, made by a forest green, lizzard-like pokemon with a leaf on its head, as well as its wrists, known as a Grovyle, named Lucar and a small turtle with a twig on its head, a Turtwig, named Kyle.
“Hey guys” Mathew said as he came over, “Oh hi Mathew!” Lucar said. Lucar was cheerful most of the time, Kyle was the same way but serious when he had a reason to be.
“So did you guys find anything?” Mathew asked curiously as he turned to his team, Team Poke-Pals.
“Yeah, I think so” Star said handing her team leader a piece of paper with her talons.
Mathew took the paper and began to read it:
My friend went into Lava Cavern with me and we became separated.
Mission: Rescue Chicorita
Location: Lava Caverns
Difficulty: Medium
Restrictions: None
Reward: ???
“Sounds good to me!” Mathew said as he put the mission into the team’s bag.
“We should store some of our stuff first” Star suggested “Lava Cavern is a tough dungeon”
The team left and headed out of the guild and into the busy streets of Sinarah Town, their home.
Meanwhile, somewhere else in another world a shadowed figure could be seen in the distance.
A young Purple Dragon flew through the air; her rainbow wing membrane glowed in the sunlight.
Heather sighed as she flew, she was sure she was lost. “Ugh, I can’t believe I forgot which way home was.”
Heather touched the necklace she had made with a strange crystal she had found on her journey. It was a black diamond shape with a bit of blue in the center.
“I wonder what this thing is” She questioned aloud. Just then, a city came into view. “I made it!” Heather said speeding up “Warfang, The Dragon City!”
Heather quickened her pace as she flew towards Warfang. However, if she had paid more attention she would have seen the small black hole quickly growing behind her.