>>539074129
not a new faction, but simply a new enemy thats a mission modifier like roachs or hivelords

Automation railgun snipers. They will try to keep a distance of over 100 meters from a target, and if they arent actively being shot at, will start to fire at you until you break LOS for more than a few seconds, which they will reposition and try again. Since a sniper would be a deadly enemy, only one would spawn at a time. Too many, and you'll get a problem on your hands after ignoring them for too long.