Gang Seo-hae is a character from the South Korean drama "Sisyphus: The Myth," portrayed by actress Park Shin-hye. She is a mysterious and beautiful woman from the future who travels back in time to save Han Tae-sul, a genius engineer, and prevent a nuclear war. Seo-hae is an elite warrior, skilled in hand-to-hand combat, sharpshooting, and bomb-making, which she learned to survive in a world dominated by gangsters and military cliques.