season 1, a very familiar name popped up as Jefferson Hall made his prequel series debut as not one but two Lannisters, twin brothers Jason, Lord of Casterly Rock, and Ser Tyland. “It was a real treat when it came up and there’s obviously a lot of pressure because they were much-loved and much-hated characters and very popular characters,” Hall tells ET about bringing the family back to life 200 years in the past in HBO’s adaptation of George R.R. Martin’s novel, . The actor, who briefly appeared in season 1 as the newly anointed knight Ser Hugh of the Vale, takes on the far more substantial roles as the two siblings, who will play increasingly larger parts in the overall battle for the Iron Throne as the series continues to unfold. For now, crafty and calculating Tyland (who dons shorter hair) was introduced as one of the men of King Viserys’ (Paddy Considine) council, while the far more boisterous and prideful Jason (appearing with longer locks) made his intentions known to Princess Rhaenyra (Milly Alcock). While speaking to ET, Hall opened up about playing the two Lannisters, how much he drew from the family’s portrayals on and what fans can look forward to.