So I'm currently writing a fanfic that follows the adventures of Pokémon trainer Red up to the last gym, and I already have a sequel planned out, but the Pokémon league isn't really important to the plot aside from establishing that Red is champion. I kinda want to do a Dragon Ball thing where the protagonist returns as a teen after training but I can't decide weather I should do a separate prologue mini-fanfic thing for the Pokémon league or just have the first chapter of the sequel be Red returning and the semi-finals and finals. What do you think I should do?
If the plot isn't too essential to the story, you may as well cut it out. Maybe the very beginning of the prologue or first chapter could have him landing the deciding blow and being declared the Champion in order to establish his position?
My suggestion would be to go ahead and skip it for now. If you want to later, you can use the stuff that happened during the time-skip as a flashback or even a spin-off.