True, everyone saying that humans made Exo's. But to be honest humans were not able to terraform any planet before they found the traveler. So i believe that Exo's were made with the technology of the traveler just like the ghosts were. So them having there own AI and extremely advance defense networks to protect them from all unknown viruses, temperatures, etc. etc. and most than likely extremely long life span is more than likely the case on how they came to be into existence. And Exo's were specifically designed to fight off the darkness, so they were made to be EXTREMELY lethal since that was the reason they were designed in the first place. And if history is any indicator when or if the darkness is ever deafeated, then most likely the awokens and humans will turn on the Exo's since they will see them as extremely lethal threats to their future prosperity, making them second class citizens to try and curve off their initial sole purpose of being. Therefore leading Exo's to have to kill the humans and awokens to live out there life OR Occupy the planets that best suit them and fend off the other races. But that is just me and what i think is the most likely possibility that will happen after the darkness is defeated. What do you think?