Xin is a war orphan raised as a servant in Qin's Jouto Village, enduring slave-like conditions under the village mayor alongside his adoptive brother and fellow orphan, Hyou. Both shared a dream of escaping their status by becoming the greatest generals under the heavens, inspired by Qin's merit-based military system. At age 14, Xin's life changed when Hyou, recruited as a body double for Qin's King Ei Sei, returned mortally wounded by assassins during a coup by Ei Sei's half-brother, Sei Kyou. With his dying breath, Hyou directed Xin to a remote shack where Xin encountered the real King Ei Sei, who resembled Hyou. Xin aided Ei Sei in reclaiming the throne, forging a bond with the king and meeting Ka Ryo Ten, a mountain tribe member who later became his adoptive sister and strategist. Physically, Xin possesses spiky black hair, hazel eyes, and a lean, muscular build. His appearance evolved from simple peasant attire—a sleeveless blue Yue shirt, cloth belt, and straw sandals—to scaled sky-blue armor after becoming a commander. He later added a spiked neck guard to his right pauldron to honor Duke Hyou. Xin wields Ou Ki's glaive as his primary weapon and carries Hyou's sword as a secondary weapon. Xin exhibits a brash, hot-tempered personality coupled with fierce loyalty to comrades and unflinching courage. He often clashes with Ka Ryo Ten in a sibling-like dynamic. Despite lacking formal education, his charisma inspires soldiers and earns respect from renowned figures like Ou Ki, Duke Hyou, and Ren Pa. He despises injustice, especially cruelty toward civilians, and enters intense rage when comrades are harmed, fueling his determination in battle. His military career began as an infantry soldier in the Keiyou Campaign. Promoted to 100-man commander for slaying key Wei figures, he later joined Duke Hyou's army. After the Battle of Bayou, Ou Ki entrusted Xin to lead a special 100-man unit, the "Hi Shin Unit" (Flying Trustworthy Unit). Under Xin, the unit grew into a 60,000-strong specialist army, renowned for turning battles through instinctual tactics and slaying enemy commanders. Key members include strategist Ka Ryo Ten, lieutenant Kyou Kai, and cavalry leader En. Xin achieved pivotal victories: killing Wei general Fuu Ki at Bayou; eliminating Zhao general Rin Ko during the Sanyou Campaign; defending Sai City during the Coalition Invasion, where he dueled and injured the Zhao Bushin Hou Ken; and slaying Hou Ken at Shukai Plains, avenging fallen mentors and comrades. This feat earned him promotion to General. His unit also captured critical strongholds like Retsubi and Gian during Qin's Zhao invasions. Relationships define Xin's journey: his bond with Ei Sei solidified when he vowed to be the king's "unbreakable sword" for unification. He views Ka Ryo Ten as family, while Kyou Kai, his vice-commander, shares mutual romantic tension—he proposed marriage after unification, awaiting her answer. Mentors like Ou Ki and Duke Hyou profoundly shaped his leadership and combat style, with Xin inheriting their weapons and ideals. His rival, Zhao strategist Ri Boku, recognizes Xin as a grave threat, marking him for death after his rise to General. Xin's dream remains becoming the greatest general under the heavens, honoring Hyou's will. He aims to unify China alongside Ei Sei, carrying the aspirations of fallen comrades. As of the Hango Campaign, he commands 40,000 troops under the Hi Shin banner, with Kyou Kai leading an additional 20,000 as a subordinate general.