I Sat by xur today and just listend to all the thing's he said. I learned that yes like his name states, he is indeed an agent for the nine. Just an agent and only sent to The tower to trade. The nine controls xur. Xur is made from cells from earth and morphed into what he is. He is from outter space and finds our inner planets weird. He cannot control his own movements. The most interesting thing xur mentioned and I quote, "Your traveler has a dark mirror". What exactly is xur trying to tell us???