That vex theory is amazing by the way, they killed him by going back in time like terminators. If only. I wanted to say a little about the hive, they are essentially the darkness incarnate. They are the absence of the light, and they are on an unholy crusade to extinguish the light. Hopefully we encounter dark guardians like Dregden Yor in the DLC. The hive are intelligent, but are our polar opposites, they want to spread corruption and darkness. They have developed dark arts beyond our comprehension that appear as magic to our eyes, they aren't to be underestimated because they are essentially humans but instead of taking in the light they chose the darkness. So they have the potential to have very interesting concepts play out.