Warning: Possibly some abuse
The New Bark Town Lab wasn't as prestigious nor as vast as Professor Oak's back in Kanto. Still, it was a lab, and they often found themselves in possession of odd Pokémon. Of those gifted to it, one was a Pokemon pretty common to the Johto region. A Mareep. But, slightly different. An extra large Mareep. There was nothing else odd about it, not really, but it was enough that the lab assistant decided it wasn't a big deal to let it live in their fields and give it their food and observe its behavior.
The young Mareep was very well taken care of. It socialized with the other Pokemon and was rather content with its life away from the difficult wilderness with the other sheep. It was well educated, and knew it was possible that at some point it may end up in the hands of a trainer or breeder, traveling the region with a lifelong partner. While this was only one possibility out of many, it was hopeful that one day it may get to find a trainer perfect for it.
"A lifelong friend!" It would hope, excitedly smiling at the daydream.
On this day the Mareep was inside its Pokéball. This wasn't irregular, as sometimes when the scientists and assistants were moving or counting or cleaning, the Pokémon would temporarily get pocketed for until they'd finished.
When it was released, however, it was outdoors. Not in the fields behind the lab, but rather, somewhere else. Standing in front of the sheep, there was a boy. A red haired, young boy, that the Mareep recognized as a trainer.
Perhaps... its trainer?
Instantly, it knew. It was now its mission to defend this boy and be his most loyal companion forever.
Silver left home without even a bag of spare clothes. He needed a Pokémon, but had nothing to catch one with. If he was going to get one, he needed to steal. Stealing from trainers was dangerous. If a trainer had one monster, they'd have others. There was no way that the Pokemon themselves would be loyal if they knew they belonged to someone else, at least without any intimidation on his side. Of the options, the Lab he saw felt like the best bet. He could get in, take one of the Pokeballs out in the open, and walk out.
Least, that's what he came up with.
He watched from outside a window, waiting for the people inside to walk away. His heart was racing while he watched and waited, but he stayed patient. Someone tapped his shoulder, but he quickly realized it was just a boy his age, and not anyone threatening. Instead of aborting the whole plan, he got him to go away by rudely telling him off.
Once the place was clear, he dashed in and took the first Pokéball he could get his hands on. He didn't have a clue what was in it, and didn't dare take more than one. He ran out. He thought he was in the clear, but soon heard people shouting. Someone had noticed someone had just ran in and took something, but wasn't fast enough to have caught him. Silver ran until he was out of earshot, and then deep enough into the forest he'd be hard to find.
When he first released the Pokemon, he was... disappointed.
Mareep. Common in Johto. Pure Electric Type. This one was above average size, at least according to what he remembered in his textbooks. Electric wasn't bad, but it couldn't do anything to Ground Types. Which... coincidentially, was the Type his father used to run a gym for.
Regardless, a Mareep wasn't the worst. For all he knew, he could've gotten something much weaker. If he was worried about Types, he could catch something else later to cover for that. This was an option now. With a Pokemon of his own, he could defend himself against the wilderness, and from people.
As long as he could keep it, that was.
He heard shouting again. It caused Silver to startle. The blue head of the sheep brushed up against his face fondly, a gesture he didn't expect.
The Mareep recognized the voices as those from the lab, but similtaniously detected the fearful feelings of the boy in front of it. Desiring to calm him, it put its face forward to cuddle the child.
Silver didn't know how to reciprocate. He only had a moment to be surprised by it before coming back to his senses and putting the monster back in the Pokeball. He felt that if he didn't want to get caught, he had to keep moving.
They make it through the forest, only having to deal with a few wild fights here and there. Silver tries to avoid these for the most part, only allowing the Mareep out for brief periods at a time. His battling style and manner of speech was extremely sharp. He knew a lot. He wasn't very patient, and he was ruthlessly direct. He'd yell commands without a hint of doubt, and at a victory would cooly call "return". Mareep didn't mind this at all, enjoying the straightforward directions over fumbling some of the lab techs seemed to do.
At the very end, even though it looked like they'd finally reached a town, they weren't out of the woods yet.
The black-haired boy that had bothered Silver earlier stood at edge of the forest. Despite being beat up from the hike, he was determined to return the stolen Pokemon back to the lab. Silver had to use the Mareep for the first time in a real trainer battle. The Mareep had no fear and followed instructions perfectly. It even managed to knock out Gold's one battling Pokemon, the Houndour. Silver was pleasently surprised by its battling power, but the other trainer had tricked Silver. While he was distracted by having won, his Trainer ID got stolen.
Despite only seeming angry on the outside, the Mareep could tell he was really just acting that way because he was scared. It didn't know anything about Silver, hardly even his name, but it felt deep inside of it that this was someone who needed protecting. It felt a feirce sense of loyalty to him.
When Gold went back to the Professor to tell him about the Trainer who'd stolen the Pokemon, Professor Elm thanked him and looked over the situation. Gold was busy getting back onto the path, but while he was gone, the Professor realized the "nefarious theif" he was worried about was just a young kid without any other Pokemon. He was worried it was a Team Rocket member, or they'd also stolen something valuable. He knew that if the Mareep didn't like this trainer, it would be able to defend itself and find its way home. He liked the Mareep, but didn't mind the idea of someone else having it at all. Honestly, if the kid had asked nicely for a Pokemon, he had a whole ton he would've been fine with him taking. Plus, if him and Sens were going to be following a similar path, it's possible he could be hearing more about where it's gone in the future.
Silver didn't know about any of this, so assumed he was still "on the run" and would need to be much more careful going forward. What if he went into a Pokecenter, and they told him that his Pokemon was stolen so he wouldn't be getting it back? These are the sorts of things he worried about. Because of this, his next big task was to aquire a team of other Pokemon. Ones he didn't have to worry about being stolen.
With how much battling they did, it did not take long for Mareep to evolve into Flaaffy. Once evolved it was easily the size of Silver, but was not here for hugging, it seemed. As his first Pokemon, and, more importantly (given how little he seemed to value his relationships with them), most obedient Pokemon, it got into the most battles. Every time the Electric Pokemon would give its all for every fight. It was only natural it'd evolve into something stronger.
As one might imagine he was slightly bothered by the indignities of having his star Pokemon be a fluffy pink sheep. He never commented on this directly, but Sens would tease him for it in battles and it obviously agitated the boy. This only motivated Cloud to try even harder in battles to prove itself as a serious Electric force that Silver would have no reason to box away.
The boy, its trainer, is rude. He is mean, even. The other Pokemon didn't like him at all. They complained about how their last trainer had abandoned them, and they didn't feel their new trainer really cared about them. He worked them all hard in battle, got frustrated at their losses, and, sometimes, would even scold them for their failures. Even during times they couldn't have won, or it was actually Silver's fault for giving poor instructions.
Even though Cloud understood why the other Pokemon felt this way, it did not share these feelings. Silver was harsh and had problems, but Cloud itself never faced the worst of it, nor did it feel Silver hated them.
One of the most callous things Silver had done happened once encountering the Gym Leader with a sick Ampharos. Ampharos, the next evolution of Flaaffy. He called her weak for choosing to try and help her sick Pokemon instead of opening the gym. She argued it could die. He didn't change his stance.
It was easy to say that he didn't care if his Pokemon died. It was easy to talk about them like they were tools instead of living beings. It was easy to stand by these beliefs that'd been instilled in him since his earliest memories. What was difficult was standing by these words when it truly counted. In the same breath where he'd say it doesn't matter if Amphy lived or died, he would carefully get his Flaaffy back to health himself because he was afraid of the Pokecenter taking it away.
Being his main Pokemon, Silver expected that the evolution to an Ampharos would come as fast as its evolution into a Flaaffy. Even when it felt like they'd trained more than enough, no sign of evolution came, and this had gotten on Silver's nerves. With all the trading and leveling had done, practically all of his Pokemon he used were all fully evolved, so it was odd this group didn't include the one he used the most.
All Pokemon evolve at different times depending on them as individuals. Some evolve fast, some evolve late. This is partly based on their biology, and partly on personality. Cloud, despite how much Silver spoke as though he wanted it, didn't feel it was right to evolve yet. Silver wanted a stronger Pokemon, but Flaaffy was plenty strong in the form it was used to. Rather, Silver felt like he was far past the point where any part of him would care for soft wool against his chin. He didn't want a stuffed animal, he wanted to defeat everything in his path to prove himself as the "Strongest".
Cloud disagreed. He didn't need to be the strongest. Or, even if he needed to be, the Flaaffy felt like evolving would rob Silver of something he secretly needed. He acted tough, but... At the end of the day, was a scared boy all alone without anyone to rely on. Why would Cloud want to rob him of its fluffy wool? No, it wasn't time, so it did not evolve. And it would not evolve for a very, very long time. Maybe this frustrated its trainer, but it felt this was correct.
Silver gets completely humiliated by Lance at the Dragons' Den. The league's season is ending soon, and Gold is leaving for Kanto soon. He gives Silver an offer to follow him, but he has a lot to mull over first.
With hardly so much as a warning, Silver releases all his Pokemon.
Confidence shattered, his idol shaming him for his behavior, and his beliefs already shaken from a year of being shown again and again they don't work, he announces to the Pokemon he'd captured that he is no longer their master, and that they are free to find other homes.
Most of the Pokemon leave. Cloud refuses, and so do three of his other Pokemon who follow Cloud's leave. Silver may have been scared, but, despite everything, he wasn't as alone as he thought he made himself.
Cloud remains as Silver's most loyal Pokemon who was there from the very start. It was there for every step of the journey, from his very first step into the wilderness to today. It's always very excited to be included and greatly enjoys socializing with other trainers and motivating Silver to new horizons. One day, it will evolve into an Ampharos, and it will be even bigger when it does.