Kim Dae-seung (born June 18, 1967) is a South Korean film director and screenwriter.
Yoo Seung-ho (; born 17 August 1993) is a South Korean actor who rose to fame as a child actor in the film "The Way Home" (2002).
 After his two-year mandatory military service, he headlined the legal drama "" (2015) and historical films "The Magician" (2015), "" (2016), as well as historical drama "" (2017).
The Magician (; lit.
 "Joseon Magician") is a 2015 South Korean period fantasy film directed by Kim Dae-seung.
 The film was released in December 2015.
The Concubine (; lit.
 "Royal Concubine: Concubine to the King") is a 2012 South Korean historical film directed by Kim Dae-seung.
 Set in the Joseon Dynasty, it centers around Hwa-yeon (Jo Yeo-jeong), who becomes a royal concubine against her will, Kwon-yoo (Kim Min-joon), a man torn between love and revenge, and Prince Sung-won (Kim Dong-wook), who has his heart set on Hwa-yeon despite the countless women available to him.
 These three characters form a love triangle which is ruled by dangerous passion.
 The struggle to survive within the tight-spaced boundaries of the palace is intense, and only those who are strong enough to overcome the hell-like milieu can survive.
The Treacherous (; lit.
 "Treacherous Subject" or "Treacherous Retainer") is a 2015 South Korean period drama film directed by Min Kyu-dong.
The Classified File () is a 2015 South Korean period crime drama film directed by Kwak Kyung-taek based on a real-life 33-day kidnapping case in Busan in 1978.
 It stars Kim Yoon-seok and Yoo Hae-jin in the lead roles.
The Piper (; lit.
 The Guest) is a 2015 South Korean period mystery film inspired by the "Pied Piper of Hamelin" legend.
 It is written and directed by Kim Gwang-tae, in his directorial debut.
Traces of Love is a 2006 South Korean film directed by Kim Dae-seung, and starring Yoo Ji-tae, Kim Ji-soo, and Uhm Ji-won.
 The film is based on the Sampoong Department Store collapse, which took place in 1995.
Blood Rain () is a 2005 South Korean film.
 A murder mystery set in 1808, it touches on historical prejudice against Roman Catholicism in the Joseon Kingdom.
 Although primarily a period thriller, director Kim Dae-seung weaves together an unconventional mix of styles—a puzzle-box mystery plot traditionally associated with detective fiction, class-conscious social commentary, lush cinematography, sets and costume design, and a flair for gore.
Detective K: Secret of the Lost Island (; lit.
 "Joseon Detective: The Disappearance of the Laborer's Daughter") is a 2015 South Korean period comedy adventure film directed by Kim Sok-yun.
 It is the sequel to 2011's "" and is the 9th highest grossing film of 2015.

Question: What nationality was the actor who starred in 2015 South Korean period fantasy film directed by Kim Dae-seung?
Answer: South Korean