The supporting cast, including Michael Sheen as Lucian and Shane Brolly as Kieran, provide solid performances that flesh out the complex relationships and histories between the characters. The character development, particularly of Selene and Michael, is a focal point that helps drive the narrative forward. Visually, "Underworld" stands out for its dark, gothic aesthetic, complementing its thematic content. The cinematography and production design create a visually stunning atmosphere, with meticulous attention to detail in the depiction of vampire and Lycan lore. The action sequences are choreographed and executed well, showcasing Beckinsale's physical prowess and contributing to the film's overall intensity.