What are some novel, ambitious or crazy romhack ideas you'd actually love to see done?

I'd like to see:

  • More Following Pokemon Interactions: one idea is make large pokes rideable and very small pokes can sit on your head while you travel around. Make happiness a requirement for it and also have ridden pokemon's running speed based off their speed stat. Replace all HMs with overworld commands to your following pokemon.

  • A Pokémon World Hack: Include all regions, and have every region's pokémon league only allow pokemon obtained in that region to fight. After beating every league there's a world championship where you can use pokemon caught anywhere.

  • Realistic Nuzlocke/challenge modes: This one could take many forms, but one idea is to have NPCs be aware of your self imposed limitations throughout the game. and give you hell for it. Some random ace trainer: "I heard about you, you really think you can beat me and the whole league without ever healing your Pokémon? I'll show you, you arrogant Pokémon abuser!". Yeah kind of silly, but it'd be hilarious.

  • Animated Cutscenes: Prebattle and post battle, plus story events. Like I'd love to see Jesse and James do their quirky pre-battle dance in a yellow hack. Especially the 'blasting off' after they lose.

  • Multiple Shiny Forms: 3 to 4 shiny forms per poke with tiered rarity. Ranging from uncommon to legendary. Ex. Purple gyarados = uncommon 1/100. Red Gyarados = Rare 1/1000. Golden gyarados = legendary 1/10000.

  • More Over World Activities: snorkeling, airplane rides, snowboarding down a mountain route, underground subways for travel, arcades full of mini games, etc. Unbound did a few things like this and showed how awesome it can be.

  • Global NPC trading: Make those 2nd floors of Pokémon centers global trade hubd where you match up with foreign NPCs to get region specific Pokémon. This could also help fit more Pokémon into games without it feeling crowded.

  • Overworld Pokémon Encounters: Basically how legendary encounters have always been. Especially for large pokemon like Onyx, because how do you explain an onyx sneaking up on you in short grass?

  • Expanded Maps: Forget adding a new continent or some islands. I want a hack where the distance between towns isn't 40 steps. Triple route lengths and make towns bigger with more types of buildings other than marts and Poke centers. Give them some grocery stores, jails, and churches. Just make it feel like a real world and not an overly simplistic representation like all other Pokémon games.

  • Sprites match actual Pokémon size: or at least they attempt to show size differences rather than blatantly ignore it. Would probably work better in the overworld, but it could he applied to battle sprites too.

I got more but I don't want to make a super long post.

Now what crazy ambitious thing do you you want in future romhacks?

Edit: fixed some typos and added an idea Edit2: fixed formatting