Complex sentence: However, when he went back to Taiwan because of his grandmother's death, he was discovered by director Yang Daqing, who cast him in the TV series named "The White Paper of Love" (愛情白皮書).
Split into simpler sentences: However, when he went back to Taiwan because of his grandmother's death. He was discovered by director Yang Daqing and starred in the TV series named "The White Paper of Love" (愛情白皮書).