Set to make a comeback, Yoo Ah-in appeared markedly different from before. The production team behind “Vampir,” tentative English title, announced Tuesday that the project had finalized its cast, including Yoo, Lee Sung-min, Lee Jun-hyuk, Kim Do-i, Yoon Kyung-ho and Choi Hyun-wook, and entered production this month. An occult thriller, “Vampir” follows an unidentified contract killer who tracks down a mysterious pagan group at the request of a clergyman. The film drew heightened attention as it will mark Yoo’s first big-screen project since he became embroiled in a drug-related controversy and went on hiatus. Yoo had been rumored to be joining the cast since last year. At the time, the actor’s agency distanced itself from the reports, stating that his appearance in the film had not been decided. As recently as last month, film distributor NEW said it remained unclear whether Yoo would appear in the film. But with his casting officially confirmed after a year of speculation, Yoo’s return to cinema is now set to begin with “Vampir.” In a photo from a script-reading session