Longclaw. The sword Jon Snow wields against the Night King’s lieutenant just like the piece of dragon glass Sam used to kill a white walker. Theories abound about the importance of Longclaw to the war, but what if the story of Longclaw goes deeper?
We all know up to this point Jon Snow’s real heritage. And we all have an idea that Jon Snow having a Stark mother and a Targaryen father brings with it special magical powers.
My theory is that Longclaw is not only made of Valyrian steel. It’s a specially forged sword containing a heart of dragon stone. It was lost to the great houses through the years and ended up at the Mormonts (or maybe given as a reward for something?)
Or another theory of mine is that Jon Snow killing a walker with his Valyrian steel sword had nothing to do with Valyrian steel at all. (Think about it. Has any other Valyrian steel sword been used to kill a white walker?) Jon Snow being of Stark/Targaryen is no ordinary man when it comes to fighting the white walkers. I think that when the war comes, those with Valyrian steel swords will find out that their swords will not kill white walkers. They’ll be killed and us viewers will be left reeling when we find out that Valyrian steel alone cannot kill white walkers. The heritage of the person wielding the Valyrian steel sword activates whatever magic needed to kill the white walkers.