Very long post, please give feedback. We know that Xur is the guy that gives us all the good weapons and kush. However, many of us wonder who he really is, and what is behind that mask. One of my theories is on the Nine. As we know, there are 9 planets in the solar system, including Pluto. My opinion is that the Nine, the group Xur is an agent for, are a group of people, one from each planet in the solar system. While there is no relevant mention of the Jovian Planets and Pluto in Destiny, except for Grimoire, it is known that Jupiter, Saturn, Neptune, Uranus, and even Pluto were colonized to an extent. These nine people may have governed interplanetary relations, like leaders of different nations. After the Collapse, these people may have hidden away and shut themselves up by controlling the Jovian worlds (mentioned in Destinypedia) from the remaining shards of humanity that still existed. Eventually, they must have made themselves known to certain people who became agents for them to sell relics like the weapons and materials Xur sells, and spread cryptic news of the Nine and the Golden Age. This brings me to Xur. Xur used to be a normal Guardian, probably human. I believe that he was sent out to one of the Jovian worlds, most likely Europa, which is a moon of Jupiter that humans colonized. What probably happened then is that there was some sort of unbelievably powerful concentration of Darkness between him and Jupiter, most likely somewhere in the asteroid belt. Unlike the Awoken, who emerged unscathed and enlightened, Xur must have been horribly scarred and injured. He probably turned back and headed to the City, and when the Vanguard found out about this, they were so terrified they banished him from the Tower. He may have lurked the streets of the City for some time, and maybe the wilderness, but eventually the Vanguard may have admitted him into the Tower again because of his valued weapons and knowledge. Since then, no one has gone out to the Jovian planets. And that is the story of who we get our weapons, armor, and good kush from. Thank you. [spoiler]I'm the saddest Guardian alive.[/spoiler]
If they were rulers, it would explain why Xur sells such valuable items.