There are some theories floating around, but aye, nothing has been confirmed.

[ The only thing she can suspect is if he's parted from Frostmourne, well, that might help. Saying it out loud though is another thing. ]

This is why it would be better if we came together as a group to discuss potential ideas. With many individuals from worlds with different experiences than our own, there surely has to be someone out there with an idea we have overlooked.