JTBC’s “Sisyphus: The Myth” finally revealed insight into Kim Byung Chul’s character! “Sisyphus: The Myth” is a fantasy-mystery drama starring Cho Seung Woo as Han Tae Sool, a genius engineer who goes searching for the dangerous truth behind his brother’s death, and Park Shin Hye as Kang Seo Hae, his savior from a war-torn future. Spoilers In the March 4 broadcast of “Sisyphus: The Myth,” the actor behind the mysterious figure known as Sigma was revealed to be Kim Byung Chul. Despite his brief appearance, Sigma (Kim Byung Chul) left a powerful impression on viewers as a figure who already knows everything that will happen to Han Tae Sool and Kang Seo Hae.