Complex sentence: After Li Jue and Guo Si made peace, the Emperor was rescued by Yang Feng, who, along with Dong Cheng and Xu Huang defeated the army of Guo Si, who returned to Li Jue to make a last-ditch effort to recapture the Emperor.
Split into simpler sentences: After Li Jue and Guo Si made peace, the Emperor was rescued by Yang Feng. Who, along with Dong Cheng and Xu Huang defeated the army of Guo Si, who returned to Li Jue to make a last-ditch effort to recapture the Emperor.