In some fanfictions, Prof Oak is bashed for being too traditional. He might be stuck in old ways of training and evaluating Pokemon and trainers. So a fanfiction could explore how his old - fashioned methods are holding back the development of new training techniques and the growth of trainers in the Pokemon world.
Another reason could be character development for other characters. By bashing Prof Oak, it allows other characters, like young trainers, to shine. If Prof Oak is shown as wrong or unfair, it gives the trainers a chance to rise above his unjust actions and prove themselves, which makes for an interesting story arc.
One possible plot could be about an adventure where Prof Oak discovers something rare that is blue in color, numbered 39 perhaps. It could be a new Pokemon with unique abilities that Prof Oak then studies. Maybe it has a connection to some ancient legend that he is trying to uncover.
Obviously, Prof Oak would be one of the main characters. And perhaps a young trainer who is helping Prof Oak in his research related to the blue 39 thing. It could be a trainer who has a special bond with a certain type of Pokemon that is somehow related to the mystery.
Often, in these scenarios, Ash might face challenges that test his determination and the support from Prof. Oak and his mom plays a crucial role in his development. There could also be unexpected friendships or rivals that come into the picture.
The plot could center around a mysterious phenomenon that is either blue or green in color. Prof Oak, being the knowledgeable character, gets involved in investigating it. It might be something that is affecting the Pokémon world. For example, it could be a new type of energy that is either blue or green, and Prof Oak has to figure out how it works and whether it's beneficial or harmful.
The fanfic could be centered around a mystery where the blue or green stole is a key element. Professor Oak might be involved in the mystery, either as a guide or as someone who is also searching for answers. The stole could have been stolen from him, or he could be trying to protect it. The color of the stole, whether blue or green, could hold the key to unlocking the mystery, like blue could be related to a water - based clue or green to a forest - related one in the context of the Pokemon world that Professor Oak is from.
It could be a young trainer. This trainer might be on a journey to discover more about Professor Oak and the significance of the blue or green stole. They might be new to the world of Pokemon and their encounter with the stole and Professor Oak sets them on an adventure.
Prof Oak could interact with trainers who are associated with either the blue or green side. For example, a trainer who specializes in water - type Pokémon (blue) might come to Prof Oak for advice on a new blue - colored Pokémon they discovered. Or a trainer with grass - type Pokémon (green) could be in conflict with the blue - side trainers, and Prof Oak has to mediate.