Bertholdt Hoover, an Eldian born around 843 in Marley’s Liberio internment zone, came from a family where his generous baker father clashed with his cautious mother. When his father’s grave illness demanded costly treatment, Bertholdt joined Marley’s Warrior program against his mother’s wishes, trading service for medicine. As a Warrior candidate, he excelled in marksmanship and intervened when Porco Galliard bullied Reiner Braun, forging a deep bond with Reiner. Inheriting the Colossus Titan, he mastered it swiftly. In 845, he deployed to Paradis Island alongside Reiner, Annie Leonhart, and Marcel Galliard to reclaim the Founding Titan. When Marcel sacrificed himself to save Reiner from Ymir’s Pure Titan, Bertholdt fled in panic before regrouping. His Colossus Titan breached Wall Maria at Shiganshina, unleashing Titans that killed one-fifth of humanity within the Walls. With Reiner and Annie, he posed as a refugee using a stolen identity, enlisting in the 104th Training Corps. Graduating third in his class, he displayed exceptional skill with vertical maneuvering gear but drew criticism from Instructor Keith Shadis for lacking initiative despite his potential. Introverted and self-described as cowardly, he envied Eren Yeager and Armin Arlert’s resolve to join the Survey Corps, preferring safety within the Interior. This facade masked turmoil over his actions against humanity. He fiercely protected Reiner and Annie, threatening Armin over fears of Annie’s torture. Though shaken by Marco Bott’s death, he genuinely cherished his 104th comrades as friends. After Reiner revealed their Titan identities, Bertholdt broke down, admitting his happiest years were training with Paradis comrades but insisting conflict was inevitable in a cruel world. At Shiganshina, he embraced cold resolve, vowing to kill all within the Walls and rejecting Armin’s psychological tactics. Accepting his role as a villain, he lamented wasting Armin’s intellect and tried to grant him a quick death. Captured by Armin, his final transformation failed. He abandoned a mid-air detonation to save Reiner, acting decisively against his nature. But when Armin’s Pure Titan attacked, his composure shattered. He screamed for help, begging former comrades and calling for Reiner and Annie as he was devoured alive. His death passed the Colossus Titan to Armin.