Complex sentence: However, the true story behind this Superman (whose real name is Lee Hyuk-Suk), is revealed: two major tragedies that befell Hyun-Suk traumatized him and left him believing he was, in fact, Superman.
Split into simpler sentences: However, the true story behind this Superman (whose real name is Lee Hyuk-Suk), is revealed. As it so happens, two major tragedies that befell Hyun-Suk traumatized him and left him believing he was, in fact, Superman.