Been enjoying Chrono Cross and I am Ab-So-LUTELY repurposing a bit of it for LANCER. The thought of going "yeah this area is a dumping ground for futures not taken" is a very interesting angle.
Now, the downside is that concept is so huge that I think I'd need to build the campaign from the ground up around it, rather than just part of it. Although I do have an area of the world map that's just covered by a haze that nobody knows what's inside...