Director Kim Han-min who helmed “The Admiral: Roaring Currents” (2014), South Korea’s biggest hit of all time with 17 million admissions, spent the last decade producing a trilogy on Adm. Yi Sun-sin, one of the most revered figures in Korean history. On Wednesday, the epic finale “Noryang: Deadly Sea” opened in theaters. “I’m just not ready to leave Adm. Yi Sun-sin. To borrow...