TL;DR: you can scan a pod at the end of Cayde's stash an apparently there is a guardian in there. This might be something already known, but during the "Cayde's Stash" mission, in the last room where you fight the Echo of Oryx, if you stand on the platform thing above/behind the stealth drive, you can actually look at the pods on the wall and scan one with your ghost. When you do, the ghost says something along the lines of this: I tried reviving that guardian because of his exception light levels, before I revived you, but he said he'd fought enough and would prefer to stay sleeping, and so your ghost revived you instead. [b]Who is this guardian?!?[/b]