>>539057374th and 5th starter options2 held item slots (one major slot for good items and a minor slot for less useful or consumable items that arent megastones nor z crystals)
eviolite
more fun field effect and move interactions-- fangames have gotten this right and fan games havent
variations on pokemonn-- different shades of bleu for squirtle. its weird that all pokemon look the EXACT same and various colors and shiny mutations would help
triple types and more delta pokemon-- maybe even the holon region as a post champian story. I really want an elec/ steel/ flying or dragon delta dragonite
for super effective attacks and resistances to be nerfed down to 1.2 to make the game less of a 1 shot or be one shot game
megas (but the stronger megas only last 3 turns)
z moves
dynamax
and a special battle frontier tent that is designed around building a team of 1 mega, one dyna, 1 z move user, one tera type
a chaos mode of all the gimmicks
I'd also like a game mode about writing code for an autobattle ai and entering frontier tournaments to see where your program fails and improve it