Game of Thrones fans got their Cleganebowl, but it didn't necessarily pan out like many fans may have thought. Cleganebowl was the long-awaited fight between brothers Sandor Clegane (the Hound) and Gregor Clegane (The Mountain). They are more commonly known on Game of Thrones as The Hound and The Mountain. The show has been setting up a battle of revenge for The Hound since the beginning, because his brother is the one who scarred him as a child. But the way Sandor took down the seemingly insurmountable Gregor is kind of an epic callback.
When they were children, Gregor (The Mountain) found Sandor (The Hound) playing with one of Gregor's old toys. Enraged, he pushed his brother's head into the fire. He only stopped when others came to Sandor's rescue. But Sandor was left with severe burn scars and an intense fear of fire. After that incident, Sandor made it clear that he one day wanted revenge on his brother. It took him eight seasons to get to that point, and Sandor did use the very thing Gregor once tortured him with to finally take his brother down — but it was frustrating to see him go down in the flames too.
Why The Mountain Was Invincible
Of course the fire was also completely necessary. The Mountain didn't die after being stabbed multiple times, and even being stabbed through the eye. That's because The Mountain was hardly man anymore. In season 4, he was poisoned in a trial by combat and left for dead. But ex-maester Qyburn performed an experiment to bring The Mountain back from certain death. However, The Mountain did not come back exactly as himself. He was a sort of zombie version (and apparently the kind of zombie that doesn't adhere to normal zombie rules), his appearance and demeanour drastically changed. Still, he served as Cersei's bodyguard until the end when confronted by his little brother. Then, nothing would stop him from killing Sandor once and for all.
Why The Hound Went Into The Fire With The Mountain
The Mountain attempted to kill The Hound the way he'd killed Oberyn Martell, by digging his fingers into The Hound's eyes and crushing his skull. Before he succeeded, The Hound realised there was no way to kill The Mountain without sacrificing himself. The Hound tackled The Mountain and drove him off the staircase ledge and into the fiery, burning city multiple stories below.
The Hound had really always known that his revenge attempt would be the last of him. It's why he told Arya to turn back and not kill Cersei. The Hound had nothing left to do. His desire for revenge is all he was living for at that point. Arya still had so many other outcomes for her life. "The road to vengeance always ends in one place," co-showrunner David Benioff said in the "Inside the Episode" following episode five. For Sandor, that was mutually assured destruction.
Co-showrunner D.B. Weiss added in the episode commentary that they'd always planned for the Clegane brothers to die together — and to die by fire. After all, The Hound's hatred of his brother was born by fire. "We knew that these two were going to die together at each other's hands and we knew that The Hound's death had to be a death by fire," Weiss said. "The one thing stronger in the hound than his fear of fire is his hatred of the person who put that fear there in the first place."
Fans probably would have preferred if Sandor was triumphant and got to live, but this is Game of Thrones and that doesn't really happen 'round these parts. But at least Sandor got his revenge and illustrated an important point along the way; revenge never quite works out exactly like you want it to.