The World's Cure

Who I am?
Well let's see, I'm Reagan. My last name? Where I come from, no one does really bother with last names.
I can't tell you much about me, either. That's maybe because I can't remember a third of my life. What I do know is that here is chaos everywhere since the earthquakes had hit. The whole map of the world has shifted, there is not much left, pretty much everything covered in water.
But this huge disaster wasn't enough. Oh hell no. With that, a disease was released. Not like ones we knew before. Demons. They are able to possess any body they want. It's as dangerous as it sounds, yes.
This all wasn't that bad until I messed up one job. One damn job.
How could I have known that this would change so much?
And now, I have no idea how long I can stay alive.