There could be a Pokemon that is a cross - breed or a genetic experiment at the school. Ash might be the first to discover its unique abilities. Another possibility is that he encounters a Pokemon that has a special bond with the school grounds, like a guardian Pokemon that he has to befriend in order to access a hidden part of the school.
One possibility is that Ash would be a bit of a star at the Pokemon school. Since he has so much experience traveling and battling. He could inspire other students to be more adventurous with their Pokemon. Also, there could be some unique Pokemon species that are only studied at the school which Ash gets to interact with.
One possible scenario could be that Ash and May are in high school and they join the school's Pokemon battle club. Ash might be eager to show off his battle skills, while May could be more interested in learning new strategies and studying different Pokemon types for her contests. They could have friendly competitions within the club and also team up against other schools in Pokemon battles.
Obviously, Ash is one of the main characters. He is the central figure around whom the story revolves. Then there are the members of his harem, though without knowing the specific fanfic, it's hard to name them exactly. But usually, they would be characters who have a special connection with Ash, whether it's through Pokemon battles, shared interests in Pokemon research, or just being good friends.
One possible plot could be Ash starting high school in a new region where Pokemon battles are a major part of the school curriculum. He could meet new friends who have different Pokemon and battling styles, and they form a team to compete in the school's Pokemon battle tournament.
Gary could be a main antagonist. He might be jealous of Ash's popularity at school and constantly try to undermine him in Pokemon battles and in front of their classmates.
They could participate in a high school Pokemon tournament. Ash would be super competitive, using his Pikachu to its full potential. May might enter with one of her cute Pokemon like Skitty. They could face off against each other in an intense battle, which would be a really exciting part of the fanfic.
Well, one interesting plot could be Ash forming unique friendships with different Pokemon in the school setting. For example, he might discover a new Pokemon with special abilities and help it overcome its shyness. Another plot could be the various competitions and challenges within the school that Ash and his friends participate in, like a Pokemon battle tournament where they have to strategize and use their Pokemon's skills to win.
Ash could be a transfer student in the Pokemon school. He'd be excited to learn new things. He might join a special class focused on rare Pokemon. His Pikachu would be his constant companion, and they'd get into all sorts of fun and mischief in the school hallways.
One possible story could be that Ash brings his unique battle experiences from his travels to the Pokemon School in the Delquan fanfiction. He might inspire the other students with his never - give - up attitude and knowledge about different Pokemon types. For example, he could teach them how to handle tough situations during battles like when facing a type - disadvantage opponent.