|There's not a day I don't regret it...that day...my son left the walls together with his little sister.... I...was always too strict with him. Telling him to take after me...to become a doctor.... After all, how could my son ever do something like that? It was me.... It was all me....|
|— Yeager breaking down after recalling his son|
In the year 817, Yeager is a middle-aged man with mild wrinkles on his forehead and face. He has short black hair, round eyes, and wears a formal outfit with a tie underneath his clothing.
In the present, he is now elderly with receding gray hair and requires a cane to walk.
At first glance, Yeager is a man who is respectful of his and his family's own history, yet he is incredibly scared of the repercussions regarding that. Therefore, he seems to sponge off of what the higher-ups tell him, as seen when officials are talking about how Grisha and Faye escaped to watch the blimp, he even calls his son an idiot. However, his choice of actions and lifestyle reveal a deep love for his family and children and a desire to see them safe and sound despite the cruelty of the world around them.
Years later, it appears he came to regret his treatment towards his son which drove him down the path that got him banished. While unknowingly speaking to his grandson Eren, Yeager broke down as he went on to blame himself in a speech about how his raising of his son inadvertently made him form a movement with dire consequences.
At some point in his adult life, Yeager met and married his wife, with whom he had a son Grisha and a daughter Faye. One day, he was confronted by a soldier who covered up the cause of Faye's death. He demeaned himself in front of the soldier and assured him that he would teach his foolish son, Grisha about the ills committed by their ancestors once again. Yeager then explained to Grisha the history of their ancestors, trying to make Grisha understand the consequences of stepping out of line. After his story, Grisha still attempted to reason with his father and that the soldier was lying. However, Yeager did not listen and forcefully reprimanded his son, further saying devils' blood ran through their bodies and urged him not to cause his parents to meet the same fate as Faye and that all they could do was stay in the internment zone and lead simple, quiet, modest lives.
Indeed, perhaps due to their low-profile lifestyle, Yeager and his wife lived a long life. In the year 832, after raising Grisha into adulthood, he witnessed his arrest by the Public Security Authorities and as a consequence became the caretaker of Zeke, his grandson.
Over the years, Yeager came to regret his previous ways towards his son and believed that if he had not been hard on him, he would not have been banished. His mindset appeared to have caused him to go through crazed episodes that he required constant supervision from his co-workers.
Yeager approaches a patient named "Kruger" (who unbeknownst to him is Grisha's second son and his grandson Eren) and introduces himself. Having noticed his conversation with Falco Grice, he tells Eren about the issues the family dealt with due to Falco's uncle's membership of the Eldian Restorationists. Noting how things got better for the Grices when Colt and Falco became Warrior candidates, Yeager asks Kruger to stop asking Falco favors for the family's sake and advises him to reunite with his own family. When Kruger notes on how touchy he seemed about family, Yeager mentions his children, expressing regrets about what fates befell them due to his methods before breaking down. He is then sent away by his colleagues.
- Yeager shares a birthday with Gordon.