Saturn, also known as Saturnus in Latin, was known as the Roman god of agriculture, justice, strength and the harvest of ancient times. Saturnus is also identified as Cronus, the leader of the Titans from Greek mythology. He is the namesake for both the planet and Saturday. His mother was Terra and his father was Caelus. He was identified in classical antiquity and is famous for castrating Caelus using a sickle, which lead to the birth of Venus.
Saturnus is the Persona representing the bond between Yu and Teddie. He was first summoned during the battle against Kunino-sagiri to protect Yu from fire attacks. However, Kunino-sagiri was able to possess Yu while still using Saturnus, who unleashed a barrage of Agidyne attacks on the team. Luckily, his attacks were blocked by Konohana Sakuya.