Suyin Beifong, also known as Su, plays a significant role in "The Legend of Korra" as a key character and Toph's daughter. She is the founder of the Metal Clan and the city of Zaofu, representing a new era of earthbending. Suyin's character is pivotal in the series as she helps Korra master metalbending and plays a crucial role in several major conflicts, including the battle of Zaofu. As Lin's sister, her relationship with Lin Beifong also adds depth to the Beifong family dynamics, making her character integral to the storyline.