Regain Lost Regions
All i did was change one number in the gameconfig file, the game already comes with this implemented, you just have to enable it, and this mod does that.
If you loose a region the game will spawn an alien base inside of it, the size of it varies depending on the invasion’s progress, after you destroy it you will reclaim the region and have 100 relation points with it (default was 500 but that was too much).