Reiner's father is a Marleyan man who had an illegal relationship with the Eldian woman Karina Braun. He is the estranged father of Reiner Braun.
Reiner Braun's father's appearance is distinctly burly and muscular, standing tall with broad shoulders, giving him an intimidating presence. He has short, wiry hair with a hair line receded to the back of his head, his beard and mustache join up with his sideburns. His facial features are defined, with thin eyebrows and sharp, bright eyes. He looks haggard with lines across his forehead and bags under his eyes.
He is shown to be a desperate and fearful man since he disowns his own son out of fear of getting hung by the Marley government for having an illegal relationship with an Eldian woman.
Appearance: Reiner Braun's father's appearance is distinctly burly and muscular, standing tall with broad shoulders, giving him an intimidating presence. He has short, wiry hair with a hair line receded to the back of his head, his beard and mustache join up with his sideburns.
Personality: He is shown to be a desperate and fearful man since he disowns his own son out of fear of getting hung by the Marley government for having an illegal relationship with an Eldian woman.
History: He met an Eldian woman named Karina Braun while working at the barracks. Even though it was forbidden, they had a secret relationship.
Relationships: Karina Braun - He previously took Karina Braun as his lover, and together they had a child. " He seems to fear Karina, believing that she wishes to take revenge for some previous action, the thought of her revenge causes him to panic, attempting to distance himself from his lover and his son.
Source: Attack on Titan Wiki, available under CC BY-SA 3.0.