Born in U.C. 0057 to the political leader Zeon Zum Deikun and Astraia Tor Deikun, Casval Rem Deikun entered the world in secrecy within the clock tower of Munzo University, hidden from Federation forces during a campus lockdown. After his father’s sudden death in U.C. 0068—an event suspected to be a Zabi family assassination—Casval and his younger sister Artesia were smuggled to Earth under the protection of Jimba Ral. They were placed in the care of aristocrat Don Teabolo Mass and given new identities as Édouard and Sayla Mass. Jimba Ral nurtured in Casval a powerful desire for revenge by repeatedly reminding him of the Zabi family’s betrayal. A second assassination attempt in U.C. 0071 resulted in Jimba Ral’s death, prompting the siblings to relocate to the Texas Colony in Side 5. There, Casval met Roger Aznable’s son, Char, who closely resembled him except for their eye colors. Learning of his mother’s death in custody in U.C. 0075 hardened Casval’s demeanor, filling him with hatred. He accompanied the real Char Aznable to the Zeon Military Academy but arranged an identity swap. When the shuttle carrying Char was bombed—in an attack meant for Casval—Casval assumed Char’s identity permanently. He enrolled using forged documents and began wearing a visor, attributing it to cosmic ray damage to explain his different eye color. At the academy, he excelled in both academic and military pursuits, forming a close bond with Garma Zabi. He incited and led the “Dawn Rebellion,” a student assault on a Federation garrison, which led to his temporary expulsion. After a period working at the Federation’s Jaburo headquarters, he was readmitted. During the One Year War, he served in the Principality of Zeon’s military, rapidly rising to fame as an ace pilot. His actions at the Battle of Loum, where he single-handedly destroyed five Magellan-class battleships in a red Zaku II, earned him the nickname “The Red Comet” and a promotion to Lieutenant Commander. Assigned to pursue the Federation’s White Base, he confronted its pilot, Amuro Ray, and briefly reunited with his sister, now going by Sayla Mass. His personal vendetta against the Zabi family continued throughout the conflict. He manipulated events to cause the death of his former friend Garma Zabi, telling him to “blame this on the misfortune of your birth.” This act resulted in his transfer under Kycilia Zabi’s command. During this time, he rescued Lalah Sune from a brothel and developed a significant bond with her. Her death in a battle between himself and Amuro Ray deeply affected him and intensified his rivalry with Amuro. He achieved his final revenge by killing Kycilia Zabi during the Battle of A Baoa Qu, where he also received a distinctive facial scar from a duel with Amuro. After the war, he traveled to the asteroid base Axis and aided in its defense against Federation forces. He supported Haman Karn as regent for Mineva Lao Zabi but eventually opposed her methods. Following the death of his lover, Natalie Bianchi, and a civil conflict, he left Axis with hundreds of followers in U.C. 0083. He returned to the Earth Sphere in U.C. 0084 under the alias Quattro Bajeena, joining the anti-Federation group AEUG. He played a central role as a mobile suit commander and mentor to Kamille Bidan during the Gryps Conflict. He publicly revealed his identity during a speech in Dakar that shifted public opinion against the Titans. In U.C. 0093, he reemerged as the leader of Neo Zeon. Advocating for humanity’s forced migration into space, he attempted to drop the asteroid Axis onto Earth. This led to his final confrontation with Amuro Ray. Both vanished in a massive psychic phenomenon during the effort to halt the asteroid’s descent. Throughout his life, he used multiple aliases, including Édouard Mass and Quattro Bajeena. He stood 175 cm tall and weighed 62 kg during the One Year War, with later records listing him at 180 cm. His eyes were initially brown, though later noted as blue. He was left-handed and bore a scar on his forehead from his duel at A Baoa Qu. His character was defined by a quest for vengeance, belief in his father’s ideologies, and a complex mix of charisma, strategic brilliance, manipulative coldness, and emotional fragility rooted in childhood trauma.