Su is a MANTIS soldier and scientist from the Previous Era. He is the best friend of Kevin and was once a doctor back before the Honkai started. He is a very calm, serene, wise, and polite man. Unlike the other Flamechasers, he dislikes and does not resorts with violence but can fight when he deems it necessary. He was one of the fewest Flamechasers to survived against Finality. He doesn't open his eyes a lot.