Saint Roswald, also known as Rosward Sei, is one of the World Nobles and resides in the Holy City of Mariejois. He is recognized as the most responsible member of his family, evident when he reprimanded his children for their behavior.
Despite scolding his children, Roswald genuinely cares for them. He has "never hit his son," even with his son's unruly conduct, and expressed deep anger when Luffy struck him. Like his daughter Shalulia, he takes immense pride in his lineage. Among his family, he is the only one who hasn't abused any citizen or slave, although he did shoot at the Straw Hat Pirates and supported his children's treatment of others.
Roswald is first seen with his daughter, Saint Shalulia, looking down on a runaway slave named Dias, who was the Captain of the Acumate Pirates. After his dog urinates on Dias, his daughter shoots him without remorse. A demon-like creature, later revealed to be Pirate Captain Jean Bart, is seen behind him.
He appears again at the Human Auctioning House with his son, Saint Charloss, and daughter, Saint Shalulia. He becomes displeased with his son for bidding on Camie. When his son is attacked by Luffy, Roswald uses his cane, which conceals a rifle, to shoot randomly around Luffy and calls for an Admiral. Sanji kicks the cane out of his hand, and Usopp accidentally knocks him unconscious after falling from the rooftop.
Roswald is known for having a "Pirate Captain collection." According to his daughter Shalulia, he has never beaten his son Charloss, something the Straw Hats did during their first day on the island. His wife(s) have yet to be seen.
When Hancock speaks of her past, she describes a man who was "the very vision of terror itself." The silhouette matches Roswald's hairstyle, suggesting that he might be the man in question.
(Source: One Piece Wikia)
