Mikasa Ackerman observed her parents' murder by human traffickers at age nine, awakening her dormant Ackerman abilities when Eren Yeager compelled her to fight. This trauma cemented her worldview of a cruel yet beautiful world. Adopted into the Yeager family, she forged an unbreakable bond with Eren, embodied by the red scarf he provided—a constant source of emotional solace. Her combat mastery surfaced early, crowning her top graduate of the 104th Training Corps. She enlisted exclusively to shield Eren, demonstrating unparalleled expertise with vertical maneuvering gear and cementing her reputation as an unmatched soldier. Superhuman strength, speed, and reflexes marked her Ackerman heritage. Though outwardly stoic, she exhibited ferocious emotional extremes when Eren faced danger, like her berserk assault on the Female Titan or near-crippling despair upon his presumed death. Mikasa’s loyalty to Eren dictated her path through every battle. She followed him into the Survey Corps, joining expeditions to reclaim Wall Maria and expose Titan secrets. Her dedication endured even as Eren’s transformation into the Founding Titan ignited global conflict. During the Marley war, she wore specialized black Survey Corps gear with thunder spears, defending Eren despite his growing hostility. In the Rumbling’s climax, Mikasa confronted Eren’s genocidal rampage. Allying against him, she resolved to end his life personally. A vision in the Paths revealed an alternate peaceful existence with Eren, deepening her inner turmoil. She ultimately beheaded him, halting the Titan curse. This act freed Ymir Fritz, erased Titans from existence, and fulfilled Eren’s hidden objective. Mikasa kept Eren’s head, burying it under a Shiganshina tree. She visited his grave lifelong, wearing the scarf until her natural death. The Lost Girls OVA delved into Mikasa’s psyche through diverging timelines, framing her headaches as links to alternate realities that amplified her obsession with saving Eren. One scenario showed her wish to stay with Eren accidentally triggering her mother’s fatal illness, reflecting themes of unintended fallout. A recurring blue butterfly symbolized cyclical timelines and her subconscious reality-warping influence, though Eren’s death proved inescapable in every iteration. Mikasa’s Asian lineage via her mother connected her to Hizuru’s Azumabito clan, signified by a wrist tattoo. This heritage offered political weight but remained secondary to her military role. Levi Ackerman shared a distant, unspecified familial tie through their Ackerman blood. Post-Rumbling, Mikasa lived quietly, marrying Jean Kirstein and raising children while steadfastly visiting Eren’s grave. Her final moments showed an elderly woman still clad in the scarf, embodying loyalty transcending Eren’s demise.