Mike Zakarius served as a Survey Corps squad leader, acknowledged as humanity's second strongest soldier after Levi Ackermann. Standing 1.96 meters tall and weighing 102 kilograms, his appearance featured olive-blond hair parted centrally, a dark mustache and beard, and grey eyes. He wore the standard Survey Corps uniform and green cape on expeditions, projecting a consistently serious and calm demeanor. His personality blended quiet reserve with unshakeable loyalty to the Survey Corps and its mission for mankind's freedom. Demonstrating strong tactical thinking and leadership, he earned respect from subordinates and peers. A distinctive, unexplained habit involved sniffing people upon first meeting, notably displayed with Eren Jaeger. Despite his courage, profound terror overtook him when confronted by the Beast Titan in his final moments, though he briefly regained composure to fight. He deeply valued his squad, expressing regret for placing recruits in danger during a Titan invasion and sacrificing himself to ensure their escape. His personal philosophy centered on resilience, often stating, "Humanity's first defeat will come only when we stop fighting. As long as we keep fighting, we haven't lost." This belief stemmed from an earlier conversation with Erwin Smith during a survey mission outside the Walls, where they discussed the continuation of struggle through surviving comrades. His story involvement spanned key events. In 844, he participated in Erwin Smith's operation to capture Levi Ackermann and his companions, physically threatening Levi during interrogation by shoving his head into mud. Later, during the 57th Exterior Scouting Mission, his acute sense of smell detected Titans converging on the restrained Female Titan; he alerted Erwin and joined the unsuccessful effort to prevent her capture. His most significant documented actions occurred during the Clash of the Titans arc. Tasked with monitoring 104th Training Corps recruits near Wall Rose, he scented incoming Titans. He dispatched Tomas to warn Commander Erwin in Stohess District, organized his squad to split into evacuation and warning teams, and remained behind to confront nine Titans single-handedly. He eliminated five in open terrain to buy time for his squad's retreat. This confrontation led to his demise. After defeating five Titans, the fur-covered Beast Titan seized his horse and threw it at him. The impact knocked him into the jaws of another Titan, crushing his legs. Despite the Beast Titan's attempts to question him about his Omni-Directional Mobility gear, extreme shock rendered him unable to respond. The Beast Titan confiscated his gear and permitted the remaining Titans to attack. Devoured alive while screaming in agony, he made a final effort to raise his sword in defiance before being overwhelmed. His abilities were exceptional. Official records rated his combat proficiency 10/10, excelling in open-field Titan combat without support. His mastery of ODM gear was surpassed only by Levi. Most notably, he possessed an extraordinarily acute sense of smell (rated 10/10), enabling him to detect approaching Titans long before visibility. Key relationships defined his service. He shared deep mutual trust and years of service with Erwin Smith, acting as his right-hand man despite finding Erwin difficult to read. His relationship with Levi Ackermann evolved from initial conflict during Levi's capture to a partnership leveraging complementary combat skills. He maintained mutual respect with Hange Zoë, another squad leader who acknowledged his leadership capabilities despite his peculiar sniffing habit. His legacy persisted among surviving comrades. Erwin Smith visualized him atop a metaphorical mountain of fallen Scout Regiment soldiers, symbolizing the weight of command decisions. Later, Erwin envisioned him among the deceased, silently questioning whether their sacrifices held meaning. Hange Zoë invoked his memory arguing against Eren Jaeger's plan for global destruction, believing he would oppose such actions. Levi Ackermann reflected on him during critical moments, including a final salute from his spirit alongside other fallen Scouts after Eren's defeat, acknowledging Levi's lifelong efforts.