Has anybody tried pkmn reborn?
It has emerald graphic style but its main features are that it is hella difficult but not unbalanced (you don't have to grind like a madman, even if that helps, but have a better strategy than your rival); way bigger world, packed with secrets of any kind, stronger pkmns are harder to get, no legendaries before the champion (if and when they develop it); mature content.
Give it a read.
https://www.rebornevo.com/pr/index.html/