It's not appropriate at all. Pokemon has a positive and clean image, and creating such erotic content related to its characters, like gym leaders, would be disrespectful to the brand and its fans. It also violates the moral and ethical standards expected in the fan community.
A fanfic about a gym leader teaming up with other gym leaders to face a common threat, like a powerful group of rogue Pokemon trainers. It could explore their strategic thinking and cooperation skills. They could use their different types of Pokemon and battle styles to defeat the villains.
One idea could be that Ash uses his unique battle style which he has developed over his journey to create a really challenging gym. He might include Pokémon from all the regions he has visited in his gym battles, making it a diverse and exciting experience for trainers. For example, he could have Pikachu lead the charge as always, but also include some of his less common Pokémon like Heracross or Gliscor.
Obviously Ash is one of the most popular characters. And then there are the gym leaders like Brock, Misty (who also has gym - related aspects in some versions), and other gym leaders from different regions.
In Gym 7 of Pokemon Black 2, the Gym Leader has a unique set of Pokemon and a particular battle style. You'll face challenges specific to that Gym's type. For example, the Gym might be focused on Electric - type Pokemon. You need to strategize your team accordingly, like having Ground - type Pokemon to counter the Electric - type attacks.
His understanding of Pokémon could deepen further. Since he now has to design challenges for trainers, he would study Pokémon types and abilities more intensively. He might discover new strategies and combinations that he hadn't thought of during his regular journey. This could also make him more respected in the Pokémon community as a knowledgeable gym leader.
A possible plot for a Pokemon Striaton Gym fanfic could revolve around a young trainer who is initially intimidated by the Striaton Gym's reputation. This trainer could start by observing other battles at the gym and learning from them. As the story progresses, they discover a hidden aspect of the gym, like a secret training area. With the help of this discovery and some new Pokemon friends they make along the way, they build up the courage and skills to face the Gym Leaders.
It's not appropriate at all. Pokemon has a huge following of young fans who look up to the characters and the world. Erotic content associated with it would not only be disrespectful to the original concept but could also have a negative impact on those young fans who might accidentally come across it.
Well, in some ash gym leader fanfiction, there could be a story where Ash has to overcome personal challenges while facing a gym leader. Maybe he's feeling unconfident, but through his Pokémon's loyalty and his own determination, he manages to pull through. The gym leader might also have their own backstory that ties into the battle, making it more than just a fight for a badge.
You can make a character who is an aspiring Pokemon chef. They use their knowledge of Pokemon food to boost their Pokemon's performance in battles at the Striaton Gym. Another way is to create a character who is a Pokemon artist and uses their creativity to inspire their Pokemon in unique ways during battles. Also, a character with a disability but who has a special bond with their Pokemon can be very interesting.