Legends say that these humans are hand picked from hell by Thel 'Chavam. Most have never even heard of them and the ones that have insist they are a spook story.
You can run and hide. You'll just die tired. ~ Sgt V. Reznov.
Its true that these men where hand picked from hell (Although his wife is not to happy about it). These men are given the most hard core special operations training and are extremely hard to track due to them already being dead. They have the best active camoflauge, training, and Exon weapons available. Ruthless in their work few that have seen the Exon Ghosts rarely ever live more then a few days to tell the tale.
The Exon ghosts mostly work for Vlad Pavlov the Exon NKVD/KGB commander. The KGB is Exon's ONI. They are the single best intelligence group.