Kycilia Zabi, sole daughter of Degwin Sodo Zabi, sovereign of the Principality of Zeon, met Casval Rem Deikun at age eight while her father served as chief aide to Zeon Zum Deikun. Political ambitions stirred within her from youth, yet recognizing her elder brother Gihren's entrenched position, she sought alternative paths to power through emerging military technologies like mobile suits and Newtypes. Holding the rank of Rear Admiral (or its army equivalent, Major General) during the One Year War, Kycilia commanded the Zeon Army's Mobile Assault Force from lunar headquarters. She directed critical branches including Special Operations, Research and Development, and Espionage. Her leadership prioritized strategic resource preservation; at the Battle of Loum, she withdrew her fleet after the main engagement, leaving mop-up to her brothers. She authorized elite units like the Midnight Fenrir covert ops team and the Chimera Corps, and actively supported Char Aznable's 300th Independent Corps, fully aware he was Casval Rem Deikun. Kycilia's defining rivalry with Gihren fueled her political maneuvering. Distrusting his leadership, she maintained independent intelligence networks. This conflict reached its peak when Degwin pursued peace talks with the Earth Federation. Kycilia positioned her fleet nearby. After Gihren used the Solar Ray colony laser to kill Degwin and annihilate the Federation fleet—initially calling it an accident—Kycilia confronted him at A Baoa Qu. Hearing Gihren admit patricide, she executed him with a shot to the head, declaring he could not escape justice. Assuming command of Zeon forces, she ordered a retreat, pledging to stand trial later. However, during her escape aboard the flagship *Chimera*, Char Aznable killed her by firing a rocket launcher into the bridge, decapitating her. Her death triggered the collapse of Zeon's command at A Baoa Qu. In spin-offs like *Mobile Suit Gundam GQuuuuuuX*, Kycilia prioritized Newtype utilization and clashed with Gihren over their treatment. By U.C. 0085, fearing Gihren's assassination attempts, she remained confined to the moon for five years until secret negotiations with Side 6's president regarding the Solar Ray's construction. Federation agents infiltrated this meeting, but she survived an assassination attempt orchestrated by Bask Om. She later recruited the protagonist Nyaan to recreate the Zeknova phenomenon, uncovering and executing Gihren's spy within her ranks to prevent the Solar Ray from falling under his control. Her relationships included a courtly dynamic with ace pilot Johnny Ridden, who gifted her a unicorn amulet as a token of loyalty; she discarded it after killing Gihren. M'Quve served as one of her most trusted officers, managing mining operations and military deployments. Despite his personal schemes, he bequeathed her his prized porcelain vase. In video games like *Gihren's Greed: The Blood of Zeon*, an alternate storyline depicts her leading the "Legitimate Zeon" faction against Gihren after Degwin's death. Kycilia Zabi's legacy encompasses her reputation for tactical innovation, loyalty to capable subordinates, and her decisive yet ultimately fatal role in the Zabi family's downfall during the One Year War.