Charlie Hunnam. Goss trained with action director and former Jackie Chan Stunt Team member, Brad Allan, learning sword and spear skills for six to seven months for his role. He and Anna Walton also learned ancient Gaelic from a dialog coach for their lines. Goss did not perceive Nuada as evil, explaining, "It's issues, his people, he's part of what he truly believes. I don't think, really, he's so deluded... [He] is driven by an ethic that was instilled by the person he has problems [with; that is,] his father, and inevitably, that leads into the conflict with him and Hellboy." Goss also noted that his character admired and revered his twin sister, portrayed by Anna Walton. He said of the prince and the princess, "There is an incestuous relationship that's not maybe overly obvious to everybody, but some people hopefully will pick up on the fact, certainly from my direction towards her." Anna Walton as Princess Nuala: King Balor's daughter and Nuada's twin sister. She is described as "very light" while Nuada is "very dark", creating a yin and yang dynamic. She elaborated on the incestuous tones between her character and Prince Nuada, "He's the dark side and she's the light side and they're pulled apart and pulled back together again, and she's trying to get away because she knows there is something she has to do. He can't let that go and they can't really do anything without each other so it's a really interesting thing." Her character also forms a relationship with Abe Sapien, and Walton noted their similarities, "They are both slightly lost souls and they understand each other." Walton spoke of her character's sense of purpose, "She feels very strongly about what she has to do in the film, and then her absolute connection and love for the Earth and what we are given. That's what she's here to protect... Her relationship with her brother, and how he is almost a part of her but she has to break away and will do whatever it takes to stop him from achieving what he wants to achieve, which is the mass destruction of mankind." Jeffrey Tambor as Tom Manning: Head of the B.P.R.D., he has a slightly antagonistic relationship with Hellboy. John Hurt as Trevor Bruttenholm: Hellboy's adoptive father, he is seen in the beginning of the film telling young Hellboy the story of the Golden