As the series is drawing closer to the end, there’s still many theories on the end game. In between all of that are how the pieces will fit together in eventually working themselves out. Two characters who have been somewhat silent (literally and figuratively) are the Mountain and Qyburn. I feel that both have an interesting possible role in Season 8, although this current season won’t really reveal much as of yet.
One thing that has become more important to the story suddenly is Dragonglass. Thus far, we only have learned that it plays a role in destroying and creating White Walkers. We saw in Season 6 the birth of the White Walkers through Bran Stark’s vision where he saw the Children of the Forest drive a shard into a man’s chest. In addition, I believe Benjen Stark’s half-dead state is related to this situation.
Given these facts, one hypothesis that I’ve been brewing over lately is how Qyburn managed to provide life to the Mountain after Oberyn Martell poisoned him. It’s assumed that the Mountain is or was dead at Oberyn’s hands but not completely confirmed. If not then he was very close to dead and Qyburn had done some off limit experiment to keep the Mountain in this animated stasis.
When the Mountain removed his helmet in approaching Septa Unella at the end of Season 6 Episode 10, we had a very dark look at his decayed, bluish face. The color is reminiscent of Benjen minus the fact that there is apparently no sign of communication ability nor individual thought process. The only thing we know is that according to Qyburn, Ser Gregor had “sworn an oath to fight the evil of the realm.”
That said, he does seem to obey commands from certain individuals such as Qyburn and Cersei while responding to people’s actions like when Jamie talked about him in the previous season. It’s not apparent if Qyburn had done something malicious such as removing Ser Gregor’s tongue since Ser Illyn Payne is not on the show anymore. But this lack of verbal communication in this state is odd considering that someone like Benjen has some level of coherence.
With Samwell Tarly making his discovery of Dragonglass in the citadel, it’s possible that the Maesters themselves with their ancient knowledge know how to manipulate its properties, which seems to include being able to cure Grayscale (which is what Samwell will do for Ser Jorah Mormont).
Given this notion and that Qyburn was at one time a Maester, it’s highly likely that he understands how to employ Dragonglass for its life saving properties. Is the Mountain then powered essentially by a battery of Dragonglass? My guess is that we’ll see this come out sometime in Season 8.
Because Leaf and the other Children of the Forest had been destroyed in the battle with the White Walkers (assuming they were the last of their kind), the knowledge of how the White Walkers can be destroyed, created or turned away at this point in time only can be understood by Bran and the Maesters. That means that both Samwell Tarly and Qyburn might be the key along with Bran in dealing with the White Walkers in a certain manner.
With this in mind, I have two ideas of how the Mountain and Qyburn will play a part in season 8. First is that the White Walkers might’ve sensed how humans are playing with “fire” in using Dragonglass for misaligned purposes. The Mountain might symbolize man’s attempt to control life itself against nature’s will and that their desire to aim south is to prevent man from uprooting the balance. We know that their purpose originally was to fight against man for the Children of the Forest, in which they eventually turned against the creators (from what we can guess). So this mad individual of Qyburn might use his skills on behalf of the queen Cersei to create an army of undead down the road and the White Walkers are marching South to stop him.
My problem with that theory is that it elevates the purpose of the Mountain and Qyburn too high up. They really are minor characters but serve a purpose in the plot. The other thing that is similar though is that the Hound might eventually be forced to fight his brother and he defeats the Mountain. In the process of slaying the Mountain, everyone learns that Qyburn has the secret of how the White Walkers can be formed with Samwell Tarly being a key person in deciphering Qyburn’s experiments. This latter theory feels more plausible. It adds more purpose to the Mountain, Qyburn and the Hound especially.
I suppose this begs the larger question of how Dragonglass plays an even larger role in the story. I can’t really see it being similar to the story of Dragonlance where an armorer like Gendry ends up forging tons of mystical weapons so that we can some epic battle scene. That’s not how Game of Thrones plays out. But I do think that the secret of life and death are definitely intertwined with Dragonglass at this point.