Complex sentence: Using the information he succeeds in persuading her to help him and she helps him uncover the tragedies in his past, including having been born with shamanic abilities similar to Yun and accidentally killing his father and sister.
Split into simpler sentences: Using the information he succeeds in persuading her to help him uncover his past. Jung-Won discovers that he had been born with shamanic abilities similar to Yun and accidentally killed his father and sister.