>What game would it be a hack of?
B2/W2 probably.
>What would it be about?
Firstly, quality of life improvements. Options for instant text, cancelling dialogue in case you accidentally talked to someone you don't want to talk to, instant turns, as well as a lot of other improvements introduced in X and Y.
But primarily, the hack would be about a large variety of shinies with different rates of appearance.
There'd be common pokemon,
Then there's a palette of pokemon which has a rate of appearance of 1 in 2,
Then a palette which has a rate of 1 in 4,
Then 1 in 8,
Then 1 in 16,
32,
64,
128
256,
and so on, until 1 in 32768.
Pokemon which appear at odds of 1/8192 or rarer are considered authentically shiny if traded to non-hacked games.
I just really like the idea of having a very large variety of colors for all of the pokemon. I love modifying palettes a lot, too, I do it all the time with stuff on fightcade. It'd make everyone's parties very different, and tell something of a story about their experiences going through the game. Maybe people who dislike certain pokemon will gain a lot of appreciation for them after catching some with different color palettes that appeal more to them.
The pokedex would also have some kind of viewer that shows all of the shiny-levels of a pokemon that have been encountered. It'd be too much to have the pokedex demand you catch all of the different types of shinies, naturally
