Complex sentence: In 2003, before starting his career, Doh-hyeong participated in dubbing of a video game for PlayStation 2,', voicing one of the soldiers and the pilots, as a winner of a game-related event at that time.
Split into simpler sentences: In 2003, before starting his career, Doh-hyeong participated in dubbing of a video game for PlayStation 2,'. He voiced one of the soldiers and the pilots, as a winner of a game-related event at that time.