Why only Dragon glass was used to destroy White Walkers? As we have seen in season 7 that Jon Snow explained to Cersei that we can only destroy them by using Dragon Glass or burning them with fire. Why not their swords have power to destroy white walkers and why does Dragon glass only have power ...

How can we hear Tyrion's pee when he is pissing off the wall? It is way, way down and there is no way we could hear this. What is the explanation?