赵襄子 / Zhao Xiangzi
赵襄子 / Zhao Xiangzi, also named 赵无恤 / Zhao Wuxu, appears in 《资治通鉴·周纪》04｜豫让 为智瑶复仇 as the Zhao leader chosen by 赵简子 over 赵伯鲁. The episode says Zhao Wuxu best understood his father’s strategic assignment, which justifies the succession despite violating the eldest-son expectation.
Zhao Xiangzi is shown as both capable and ruthless. He helps destroy 智瑶, reportedly uses Zhi Yao’s lacquered skull as a drinking vessel, and later conquers 代国 by killing the Dai ruler, his brother-in-law, during a feast. The same source says this conquest causes Zhao Wuxu’s sister to kill herself.
His succession decision creates the episode’s second Zhao problem. Instead of appointing one of his own five sons, he keeps his dead elder brother in mind, sends 赵伯鲁’s son 代成君 to Dai, and later designates Dai Chengjun’s son 赵献子 as heir. 赵桓子 briefly overturns that arrangement, but Zhao clan leaders restore Zhao Xianzi after Zhao Huanzi’s death.