Go into the Vault of Glass, kill your way to the boss battle. When the guy you killed numerous times before appears, drop your gun, pull up a chair and have a one-on-one conversation with him. Get to know each other. Do some bonding. You may know he loves Golf, but stuck in that vault, he has gotten really cranky. He may tell you his most deep secrets, may even let you learn how to time shift. You would make a nice Vex. Learn his name well, it's all you will ever hear from that point in time...