Spoilers for Game of Thrones, season 7 below.
Everyone from Jon to Stannis to Dany to Moonboy has been floated as the possible fulfillment for the notorious "Azor Ahai" prophecy, the age-old foretelling that a "prince/ss that was promised" will return to Westeros, essentially, to defeat the White Walkers forever.
The prophecy is unbelievably complex, but these are the main points that the coming savior must hit in order to satisfy the foretelling. Via Westeros.org:
- After a long summer, when the stars bleed and the cold breath of darkness falls heavy on the world
- Variant: When the red star bleeds and the darkness gathers
- He shall be born again amidst smoke and salt
- He shall wake dragons out of stone
- He shall draw from the fire a burning sword, Lightbringer