Saul is a giant, though not from Elbaf, as he was born elsewhere. He joined the Marines and eventually rose to the rank of Vice Admiral. Prior to the main storyline, Saul traveled through the Grand Line, where he encountered numerous Devil Fruit users, though details about his adventures remain scarce.
Saul embodies the role of a big, friendly giant who is somewhat shy and timid. Despite his loyalty to the Marines, he questioned his orders on at least two occasions, indicating that he adhered more to 'Moral Justice' than the Marines' code of 'Absolute Justice.' His unique laugh, "Dereshishishishi," is something he finds slightly embarrassing, yet he enjoys seeing others laugh and have fun. He encouraged Robin to laugh, even when it might hurt, which explains why she often smiles in times of trouble.
Saul was one of three significant influences on Nico Robin. He wore a cowboy hat that Robin would later adopt herself. Through their interactions, Robin learned about the Will of D, due to Saul's middle name. This knowledge later prompted her to question Luffy about his reasons for fighting, referencing the Will of D.
Saul shared a strong friendship with Vice Admiral Kuzan, who later became known as Admiral Aokiji. Both held similar views on Moral Justice. It was largely out of respect for Saul that Kuzan allowed Robin to live, considering it a final favor to his friend.
