乐乘 / Le Cheng
乐乘 / Le Cheng enters the wiki more directly through 《资治通鉴·秦纪》104｜阴谋失算让秦国版图又又又膨胀了. The source describes him as a former 燕国 general who had been defeated or captured by 廉颇 and then came into 赵国 service.
When 赵道襄王 succeeds, he orders Le Cheng to replace Lian Po. Lian Po refuses the command transfer, attacks Le Cheng, and then flees Zhao. Le Cheng’s role is therefore less an independent achievement than the trigger point for Zhao’s late command rupture.