For a little background, Azor Ahai is a mythical figure who used his powerfully magical sword Lightbringer to defeat the invading White Walker army during the Long Night Winter in Westeros thousands of years ago.
A prophecy claims that during the next long Winter, when the White Walkers are again closing in on the seven kingdoms, Azor Ahai will return as "the prince that was promised," a hero born "amidst salt and smoke" who will "draw from the fire a burning sword." This hero is the one who will beat back the dark army.
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