Dirk is a man of average height and build, with long, dark blond hair that he keeps pushed back out of his eyes. He also has a thin beard on his chin and cheekbones, and a small mustache. When not wearing the standard Scout Regiment uniform his attire consists of a white button-up shirt, dark pants, and a black vest.
Dirk appears to be a rather calm, serious man. When violence erupts among the other scouts, Dirk only makes a casual note of their behavior, and makes no effort to break up the fighting or intervene in any way. He demonstrates the more serious aspect of his personality when the citizens of Trost see the Scout Regiment off with fanfare, obviously dissatisfied with the commotion that they are causing despite admitting that the scouts have never received such praise.
Dirk is seen attending a meeting between Erwin and the other Scout Regiment officers to discuss the recent revelations involving Eren Jaeger's father. After the meeting, Dirk suggests possibly punishing Keith Sadies for withholding information from the Military, but Hange Zoë dismisses the notion, claiming that Keith is not worth the effort.
Later, Dirk can be seen watching with his fellow leaders as the scouts fight each other for the meat that is being served in celebration of the mission recapture of Wall Maria. Although Dirk takes special note of the violence that begins erupting as a result of the meat, he is not concerned enough to try to stop it, choosing instead to ignore the brawls.
The day of the operation, all soldiers are ready at dawn. Dirk and other high-ranking soldiers salute to members of the other branches and head to the Wall. As the scouts are preparing to depart, they are met with unexpected fanfare from the citizens of Trost, to their surprise. Dirk is annoyed to learn that Flegel Reeves was the one to leak the news of their departure to the public, although he concedes to Klaus that it is notable that this is the first time the Scout Regiment has ever been seen off with such fanfare. He and the other scouts are silenced by Erwin, who begins cheering along with the crowd before ordering the scouts to begin their final operation to reclaim Wall Maria.