Complex sentence: After the death of Li Linfu, his rivalry with General Geshu Han and new chancellor Yang Guozhong created military tension within the Empire, which was increased by the promotion of Yang Guozhong to Chancellor.
Split into simpler sentences: After the death of Li Linfu, his rivalry with General Geshu Han and new chancellor Yang Guozhong created military tensions within the empire. This animosity between competing powers further was increased by the promotion of Yang Guozhong to Chancellor.