Lightbringer & The Citadel [book spoilers/speculation]
Something mentioned recently in the season 2 rewatch got me thinking about the light bringer myth/prophecy from the books. What if lightbringer is made of obsidian? We know that obsidian kills the white walkers and fire destroys the dead. What about a solid obsidian sword that is also aflame? When discussing the obsidian candles as a citadel rite of passage, Jim & A.Ron mused that perhaps it is possible to light them but that the knowledge was forgotten. The tradition remained as a lesson on what cannot be known. If the method for lighting obsidian was anything like the lightbringer myth (involving blood sacrifice), it would make sense that the citadel would do away with this. We know that they don't approve of human experiments. I think this would bring further narrative purpose to Sam's citadel visit in the show and the faceless man's presence at the citadel in the book. Ultimately I don't think we'll see any more citadel in the show but what do you guys think about my theory?