First, you need to have a good understanding of the character Ash Ketchum. Know his traits, his goals, and how he behaves in different situations. Then, when creating a yaoi - themed story, think about the relationship dynamics you want to explore. But remember to keep it in line with the general feel of the Pokemon world. And for the 'lemon' part, be careful as it can make the story more adult - oriented and might not be suitable for all readers.
There are many Ash Ketchum yaoi lemon fanfictions out there, but it's difficult to single out the most popular. A lot of it has to do with the way the fanfic community promotes certain works. Some fanfictions might become popular because they offer a unique take on Ash's relationships in a yaoi - themed way. However, this type of content may not be mainstream and can be a bit controversial as it goes against the traditional view of the Pokemon series.
One common theme could be the rivalry - turned - romance. Since they start as rivals in the Pokemon series, it's interesting to see how that competitive relationship can transform into something more affectionate in fanfiction. Another theme might be their shared adventures in the Pokemon world influencing their relationship, like going through tough battles together and growing closer because of it.
I'm sorry, but I don't really have specific yaoi fanfiction to recommend. However, you can try searching on fanfiction platforms like Archive of Our Own (AO3). They usually have a large collection of fan - made stories about various characters, including Ash and Gary.
One good fanfic could be 'Ash's Homecoming'. It focuses on Ash returning home to Pallet Town and his heartwarming interactions with Delia. It shows their strong bond through simple daily activities like having dinner together and sharing stories of his adventures.
Maybe a new, mysterious villain who has a grudge against Ash or wants to use his skills for their own evil purposes. This villain might be from a far - off region and has special powers that allow them to hypnotize people. They see Ash as a useful tool to carry out their plans in the Pokémon world.
First, think about their relationship. Ash is a determined Pokemon trainer and Delia is his loving mother. You could start with a simple idea like Ash coming home for a surprise visit. Then, create a plot around that. Maybe there's a local Pokemon problem in Pallet Town that Ash helps with, with Delia's moral support.
His rival, Gary, could be a likely candidate. Gary has always been competitive with Ash, and in this fanfiction, his jealousy could reach a boiling point, causing him to betray Ash for his own gain, like trying to steal his Pokémon or get credit for his achievements.
Ash could become more confident and wise as a Dragon Master. His decision - making skills would improve as he deals with powerful and often unpredictable dragon Pokémon.