Board Thread:Spoilers!/@comment-24674051-20160927161944/@comment-24674051-20160929164257

I had a thought about a way that they could bring Robin back. It is defintely WAAAAY out there in terms of theories, and I don't think they would actually do it, but I'll put it out there for everyone to shoot down with their Arrows. XD

The theory starts with a misconception regarding the Olympian Crystal. It's function was not to obliterate souls, but to trap them. And so long as the crystal remained in existance, the souls thus entrapped could never escape. Even when Hades held the broken crystal, it was still in existence, and any souls previously trapped were still trapped. (Side note: it is not clear if Hades would be fully aware of the details of the Crystal, those details may only be known to Zeus).

After the crystal was destroyed by the combined effects of stabbing Hades and untethering the magic, all of the souls in the Crystal were released. They couldn't very well go back to their former lives, as many have been dead for a very long time. But there was a built-in failsafe for the trapped souls. They were magically given their bodies (or at least reasonable replacements that represented their original identity) and were sent to the LoUS, since their stories were forceably put on hold by the use of the Crystal. From there, they could continue their existance.

This influx of souls from the Crystal would not have occurred until after Hyde was in SB, since the destruction of the last piece of the crystal was not completed until Regina restored the magic to SB. So Robin would appear with a host of others in the LoUS. From there, it would just be a matter of Robin figuring out how to get a message to Regina so that they could be reunited.

As I said, not the best of theories, and way out there, but there it is.