Hannes captained the Garrison unit stationed at Shiganshina District. He was tall and well-built, sporting short blond hair and a thin dark mustache, typically dressed in his Garrison uniform over a v-neck shirt. Initially, he displayed a lax attitude, often drinking irresponsibly while on duty and dismissing young Eren Jaeger's fears about Titans, citing the Walls' century-long impenetrability as reason for complacency. A deep personal debt bound him to the Yeager family; years prior, Grisha Yeager had cured Hannes's wife of a plague. Hannes attended Grisha and Carla's wedding, solidifying the bond. When Wall Maria fell, Hannes rushed to reports of the Yeagers' peril. Finding Carla trapped under debris with a Titan approaching, he intended to fight. Yet, the sight of the distinctively wide-grinning Titan froze him with terror. Overruling Carla's desperate pleas to save the children, he retreated with Eren and Mikasa, leaving Carla to be devoured—an act driven by paralyzing fear. This failure haunted Hannes relentlessly. Escaping, Eren physically assaulted him in grief-stricken fury. Hannes did not retaliate; instead, he tearfully admitted his cowardice prevented Carla's rescue, repeatedly apologizing as he guided the children to relative safety. This event sparked a transformation. Over the next five years, Hannes rose through the Garrison ranks to captain, demonstrating increased dedication and professionalism. He later encountered Eren, Mikasa, and Armin at their military graduation, expressing remorse for his past failure and lamenting his inability to repay Grisha. His concern for the trio remained evident during subsequent crises like the Battle of Trost District, where he monitored their safety from defensive positions. His unresolved guilt resurfaced violently during the Clash of the Titans arc when he recognized the same Smiling Titan that killed Carla. On a mission to rescue Eren from the Armored and Colossal Titans, Hannes intervened to protect Eren and Mikasa from this Titan. Explicitly stating his desire to avenge Carla and redeem his earlier cowardice, he engaged it in fierce combat. Despite his determination, he was overpowered and killed, his death witnessed by Eren and Mikasa. In later reflections, Eren included Hannes among those whose deaths he felt responsible for due to the consequences of inheriting Titan powers.