|Not a day goes by that I don't regret it... The day my son took my daughter outside the walls. I was always too harsh on him, insisted that he became a doctor. It was me... It was all my fault...|
|— Jaeger breaks down in regret after recalling his son|
In the year 817, Jaeger is a middle-aged man with mild wrinkles on his forehead and face. He has short brown 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, Jaeger 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 leech on what the higher-ups tell him, as seen when officials are talking about how Grisha and Fay 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, he came to deeply regret his treatment towards his son which drove him down the path that got him banished, to the point where it traumatized and caused him to go through crazed episodes that he required constant supervision from his co-workers. While unknowingly speaking to his grandson Eren, Jaeger 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, and believed that if he had not been hard on him, he would not have been banished.
Jaeger was confronted by a soldier who covered up the cause of Fay'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. He 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, Jaeger 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 Fay and that all they could do was stay in the internment zone and lead simple, quiet, modest lives.
Jaeger 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, Jaeger 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, Jaeger 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.
- Jaeger and Dennis Aiblinger share the same Japanese voice actor.