Game of Thrones
Oberyn Martell (Pedro Pascal) HBO/Sky Atlantic

Game of Thrones Season 4 Episode 8 titled The Mountain and the Viper will return next Sunday and fans of the fantasy series are eagerly waiting to witness the massive fight between the Red Riper and the Mountain.

The fierce fight will decide whether Tyrion Lannister will live or he has to accept the verdict of death for murdering the young and sadist king Joffrey.

In previous episode 'Mockingbird', an angry and broken Tyrion asked Tywin to decide his fate in a battle, which was accepted by the latter.

However, Cersei was cunning when she appointed the cruel Gregor Clegan aka the Mountain as her champion to fight against Tyrion.

In his desperate search for a champion, Tyrion asks his own brother Jaime and Bronn for help and they refused it. Nevertheless, Red Viper aka Prince Oberyn instantly accepted his request and offered his help to fight Tyrion's champion.

For Oberyn, this is a perfect opportunity to settle his vengeance against The Mountain, who raped and killed his sister and her children 20 years ago.

In an interview with Entertainment Weekly, showrunner Dan Weiss revealed some important spoilers from the upcoming episode of HBO's blockbuster drama.

Game of Thrones Season 4 Spoilers: Tyrion to Die if Prince Oberyn loses to the Mountain?
Tyrion Lannister in Game of Thrones Season 4. Game of Thrones/facebook

"It's one of the best--if not the best--combat scenes we've done so far. It's not just people hacking at each other with spears and swords. It's the culmination of 20 years of anger and hatred and thirst for vengeance coming to a head in this amazing set piece that [stunt coordinator Paul Herbert and swordmaster C.C. Smiff] have put together. The fight delivers beyond our expectations," he said.

Weiss claims that the fight will be massive with dangerous performances from both Oberyn and the Mountain.

"It's one of those fights that from the very beginning of the process of planning the show before season one we knew would be a high point if done properly. And it's a real challenge because The Mountain is The Mountain, you need to find an enormous human being who can also deliver what you need on physical front," Weiss explained.

"And you need an Oberyn who delivers what you need as an actor and pull off the extremely strenuous side of that fight, which we shot over several days. We were lucky to find Pedro Pascal for Oberyn, who gives such a stunning, fun, and dangerous performance.

"And Hafþór for The Mountain is a truly unusual specimen--I believe he's the third-strongest man in the world and a former basketball player, so he knows how to move. To see somebody who is 6′ 9″ and moving the way he does in person is a surreal sight to behold," he added.