OMG. Just finished reading the GI cover story.
Folks, this is why we eagerly awaited next gen systems.
NPCs in this game at going to function just like you're character. While you're off doing whatever they're dying, getting promoted/demoted,leveling up, fighting battles and more.
If you fight someone and they live, they'll remember you. They might stop at nothing to see you dead or they might go back to camp telling everyone you're a badass.
The next time you see them, they might run. The ENTIRE CAMP might run depending on how legendary they think you are.
It's radiant AI applied to every character in the world. Monolith is calling it the Nemesis System.