This hack idea is based of the game half-life 2 (I don't want to make stupid references, but a completely different plot)
Rough sketch: The world has been taken over by the combine and they use pokemon as their slaves for various jobs. Actually having a pokemon is a sign of rebellion towards the combine, and it can get you killed.
You're living in City 11 (That's how every city will be numbered) and (at some point) will join the rebels and get a pokemon. Then your goal is to get to city 01 and...
(I dunno, i told you it was a rough sketch)
Don't think i will put things like zombies in, just the general theme. And i will have to give the combine pokemon, which is kinda silly.
I dunno, what do you think?
Edit: I posted the same thing at the storyline thread. Not sure if i should delete this one.
Anyway i really would like to do this hack so if anyone wants to help they can call out.