刘黑闼
In the book of Shuo Tang, Luo Yi was always loyal to Sui Dynasty, but Luo Cheng took part in Wagang Fort rebellion. Later, after the failure of Wagang Fort rebellion, Luo Cheng joined Wang Shichong’s force. Years later, he was persuaded by his old time friends to switch to Li Shimin’s troop to fight for Li Yuan's Tang Dynasty. He defeated the ally of five warlords (Wang Shichong王世充, Meng Haigong 孟海公, Gao Tansheng 高檀晟, Zhu Can朱灿 and Dou Jiande 窦建德) within one day. Two years later, another ally led by Liu Heita(刘黑闼), Xu Yuanlang(徐圆朗), Shen Faxing(沈法兴), Gao Kaidao(高开道) and Tang Bi(唐壁) invaded Tang Dynasty. Luo Cheng took part in this war and he was killed by a general in Liu Heita's troop, Su Dingfang (苏定方), with arrows. However, the story behind that was the envy of Li Jiancheng and Li Yuanji towards Li Shimin. Luo Cheng was actually a victim of political conflicts among Li Yuan's sons.