"The stunt guys were so excited about what was coming up," says Enzo Cilenti, who plays the slaver Yezzan.

Game of Thrones is ready to unleash another huge battle.

Sunday's episode will feature an epic gladiatorial match in which Jorah (Iain Glen) hopes to prove his devotion to Daenerys (Emilia Clarke), who in the previous episode banished him once again.

Glen previously told The Hollywood Reporter it would be a "massive, massive fight" in which Jorah would "risk all." Now Enzo Cilenti, who plays the slave master Yezzan zo Qaggaz, is sharing more details.

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"The stunt guys on that show were so excited about what was coming up," says Cilenti, whose character enslaved Tyrion and Jorah earlier this season. "It's something they'd been working on and choreographing for months."

The episode comes after the unexpected battle between Jon Snow (Kit Harington) and the White Walkers — something that had yet to take place in George R.R. Martin's books. The same is true of the upcoming battle in the fighting pits.

In a chat with The Hollywood Reporter, Cilenti talks Yezzan's motivations and reveals details of BBC America's upcoming fantasy drama Jonathan Strange & Mr. Norrell , in which he plays the mysterious Mr. Childermass .

In your first scene, you come in and get to be mean to Tyrion and Jorah, characters viewers have loved for years. Was that scary?

That's really scary, doing that. I had worked with Iain Glen before. It was a big surprise to me that Peter Dinklage and I had a mutual friend in common, which I didn't know until I'd met Peter. There are important scenes in that first episode, and it can take a while to find your feet on a set. You know you have to hit the ground running, which isn't always an easy thing to do, but I was really encouraged to do that.

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Your character, Enzo, agreed to let Jorah compete in the fighting pits once again. What was the key to getting that short but important scene right?

My character was very low on the moral compass. He's very greedy, but there's a little redemption there. Even within that small period, there's a nice journey to go on. That's a hallmark of great script writing. When you're handed those [scenes], it's a pleasure.

Did they give you hints about that battle with Jorah?

We set it up absolutely beautifully. The stunt guys were so excited about what was coming up. It's something they'd been working on and choreographing for months. Fans of the show are going to be really bowled over.

In Jonathan Strange, your character is very mysterious and in control. What drew you to him?

It's the exact opposite of my life. It's a wonderful departure. He's a thief, he's a man of the street. He represents the poetic nature of Yorkshire and its history of magic. I thought, "I'll never get to do that!" They'll get somebody really brilliant and famous to do it. I couldn't believe it when I'd found out I'd gotten the part. It was the night before my sister's wedding in Portugal, and I ran around the entire hotel complex. There were two projects offered to me at the same time before I found out I'd gotten Childermass and I turned them down, which I never, ever had done before.

Did you have any concern that they would be able to successfully adapt the book?

It's the first question. How on Earth do they make that mighty tome work? Initially, the BBC offered them six episodes. Very quickly [writer] Peter Harness and [director] Toby Haynes said, 'We can't do it.' So they gave them the extra hour. It's a slightly weird, seven-episode thing. As soon as we got the scripts, with the book so fresh in my head — I probably only finished it a month before — I was blown away by how much of the book they'd gotten into it. And how it made sense and how it stood together.

What do you think the key to translating it from page to screen was?

You've got these magnificent tools when you are shooting. It really evokes the dark, musty, literary feel you get from the book. The first scene I saw was the first time Mr. Norrell meets the man with the thistle-down hair [Marc Warren]. The greenness and the darkness and the echoes of that made me feel like I had a really heavy book in my right hand.

Game of Thrones airs Sundays at 9 p.m. on HBO. Stay tuned to The Live Feed for more from the series.