Lin is a supporting character in the anime Arknights: Perish in Frost, which adapts chapters four through six of the main game storyline. She is a young woman from the mobile city of Lungmen and serves as a Caster operator with the Phalanx classification. In the game, she is formally known as Lin Yühsia and is a Lungmenite who becomes an operator for Rhodes Island after events involving the Dossoles Holiday and the main story. Her background ties her to the upper echelons of Lungmen society, and she carries a strong sense of duty toward the city and its people. In the anime, she appears primarily during the Lungmen arc, where Rhodes Island operators work with the Lungmen Guard Department to counter the Reunion Movement’s plans. Her role is that of a calm and composed figure who uses Arts to deploy defensive barriers and crystalline shields, protecting allies and controlling the battlefield. She is also capable of dealing significant Arts damage when needed. Her motivations stem from a desire to safeguard Lungmen and uphold stability, even as the conflict between the infected and the non-infected escalates. Key relationships include interactions with other Lungmenite operators and officials, particularly those connected to the city’s leadership. Over the course of the story, Lin demonstrates a steady resolve and a willingness to cooperate with Rhodes Island, showing growth in her understanding of the broader struggle. Her notable abilities revolve around her Phalanx combat style, which combines strong defensive Arts with measured offensive strikes, making her a reliable operator in both protection and counterattack situations.