Board Thread:Episode Discussion/@comment-14138255-20171107165310/@comment-14138255-20171111212558

Even discounting aliens, Dust not working out of the atmosphere for the sole purpose of keeping Ozpin on Remnant is interesting (just replace aliens with The Gods), and it seems like the kind of thing Ozpin would do if not for the fact that space-travel as they know it is impossible because of that.

For context, I mentioned Kane in that original comment. Kane was the main villain of the Command and Conquer  RTS series who always came back at the beginning of every game despite dying numerous times and is clearly something else, even when actual aliens invade later. It's eventually revealed he was an alien who crashlanded on Earth thousands of years ago and has been manipulating people into war to develop technology and trigger events to eventually escape the Earth.

Convoluted I know, but it's kind of what I imagine Ozpin would have been capable of. Faced with an impossible task of trying to defeat Salem for all eternity, he could have opted to instead escape Remnant and wander the stars as an immortal, except Dust is inert outside Remnant, making space travel useless and trapping him on the same planet as Salem.