石敬瑭 / Shi Jingtang
Shi Jingtang / 石敬瑭 is the Later Jin founder named in EP252 《太平年》之外的五代十国，什么样？’s periodization of 五代十国. His rise marks the episode’s transition into the stage where the Khitan factor becomes central to central-plain politics.
The source also says Wang Hongjie’s planned third volume begins around the late Later Jin and Jin-Liao conflict before moving toward 赵匡胤 / 宋太祖 and Chenqiao.