More Double Battles in the main game would be great, as are more interesting strategies.
But my number one improvement has to be an optional Trainer School like Earl's Pokémon Academy from
Pokémon Stadium 2.
Earl's Pokémon Academy is by a country mile the best tutorial in the games. I want it back ASAP because it would benefit anyone.
It teaches everything you need to know about playing the game somewhat decently, from the basics to more complex stuff. You have things like Type match-ups, status conditions, move categories, stats, but you also get to learn shit like additional effects of moves and recovery, as well as things that were new to GSC, e.g., held items. And at the end of every lecture, you get to answer questions to prove you paid attention to the lesson.
This is already great, especially compared to what other games in the franchise teaches the player, but the cherry on top is the battles.
That's right, in Pokémon Stadium 2, you are given special "puzzle" battles to prove you know how to battle well. Because good teaching isn't just lecturing. You are thrown into a 3v3 battle, and you have to find the three best available Pokémon.
A memorable example is early on, a battle that teaches Moves with a semi-invulnerable turn and Moves with a charging turn.
- Your opponent uses moves like Solar Beam, which are strong but came with a significant drawback: a charging turn.
- You are given six Pokémon, three of which having moves like Dig or Fly to evade the damage dealt by Solar Beam and the rest.
For me, this is one of the most memorable battles in the franchise. It's not a self-imposed challenge, it's not a boss battle, it's just a lesson.
And this was back in Generation II! Can you imagine the lesson battles if they were made after that? With Double Battles and its own set of strategies? New battle types like Triple and Inverse? The Physical/Special split? New moves like Stealth Rock or the Pledges, Abilities, the Fairy type, new items? You can do so fucking much with all these new toys!
Alright, gushing over. All I want to say is,
Earl's Pokémon Academy = good, please bring it back.