ASHES

In the year 2089, Earth is invaded by an unknown alien race. The people of earth refer to the aliens as the "ASHA". You cannot see the Asha. It is hard to come into physical contact with them and it is normally hard to hear them. They're invisible most of time to the humans. Through decades of fighting them and having very little information to go off of, the world has become a wasteland. The ASHA created outposts called "ASH ZONES" around the world. The ASH ZONES are pockets of land in which the ASHA have commandeered for terraforming purposes. The ASHA secrete ASH like substance from their bodies that make the area they're in uninhabitable for humans. Humans have to go into each ASH-ZONE with masks for filtration and to begin reversing the process. The ASH like substance from the aliens act as a deadly hallucinogenic that psychologically torments the victim until the host dies.