In the 2016 South Korean zombie film Train to Busan, Kim Eui-sung plays the infected passenger Yon-suk.
Yon-suk is a selfish businessman traveling on the train when the zombie outbreak begins. As the infection spreads through the carriages, he repeatedly prioritizes his own survival and persuades other passengers to exclude people who may be infected. His actions make him one of the film’s principal human antagonists, even though the zombies create the immediate physical threat.
Kim Eui-sung’s performance helped make Yon-suk memorable because the character represents fear, social division, and ruthless self-preservation rather than supernatural evil. The film’s central conflict therefore involves both the infected passengers and the choices made by the surviving humans.
Train to Busan was directed by Yeon Sang-ho and stars Gong Yoo as Seok-woo. It premiered at the 2016 Cannes Film Festival before becoming an international success and inspiring the animated prequel Seoul Station and the later sequel Peninsula.