Actually, I have a younger brother, Yu Wenhui, but it didn't appear on TV.
My son is the second hero and general Yu Chengdou in the world after Li Yuanba.
His brother's name is Yuwen Zhiji (called Yuwen Zhiji in Romance and his brother's celebrity in New Tang Book).
In Romance, Yu Wenhuaji is treacherous and has a very brave son, Yuwen Chengdou. But in fact, Yuwen Chengdou doesn't exist, at least in the official history. No prototype. Yu Wenhuaji has two sons, Yuwen Jicheng and Yuwen Jicheng.