>>12232249Max still exists but stays at home. Jessie, James and Meowth now out of a job decide to join Team Magma and are given new uniforms for their cause. This changes their role from trying to steal Pikachu to roles closer to Team Magma in the games. Butch and Cassidy join Team Aqua.
Harley is May's main rival, Drew is never introduced. May's contest opponents reappear a bit more often. Ash also gets a new rival who is pretty much Paul from Diamond & Pearl.
By the league Ash has Sceptile, Glalie and actually calls on his reserves to balance out his team. The league ends with Ash winning.
The Battle Frontier becomes a way for Ash to prepare for the Elite Four. The arc is similar but takes place in Hoenn. Ash and May grow closer and we finally get a romance for Ash.
Ash faces the Elite Four but is inevitably defeated by the champion, Steven (who actually got more build up as the champion). Ash and May part ways to promising to meet again when they achieve their goals.
Sinnoh has Ash travel with Barry and Dawn. Dawn's Piplup actually evolves and very early in the series. Rather than Paul this series introduces the concept of rivals traveling together as Ash and Barry both aim for the league. Jessie, James and Meowth join Team Galactic.
With HGSS's release a return of Team Rocket story presents itself. It happens after Team Galactic are defeated leading the Team Rocket trio to return to their roots, only this time they are given their black uniforms and present a greater threat.
The league is the same. Ash decides to climb Mount Silver and train with the Pokémon Master who lives up there. We get a time skip.
Unova is more or less the same but Ash is now older. The Team Rocket Vs Team Plasma plot actually continues. When Ash challenges the league he wins (none of that god awful league that actually happened) and the current arcs are his training for the Elite Four. I'd then plan for Ash to win and for his journey to end.