The brothers didn't look alike.
Amazingly, while the Emperor's appearance was rather ordinary, all of his sons were exceptional. Perhaps it was because their mothers were all beauties of different types.
Indeed, the saying 'the dragon has nine sons, each different' held true here.
As the son of the dazzlingly beautiful Jin Zhuzhu, Li Hongyuan stood out amongst the princes. In terms of sheer physical attractiveness, Li You was quite some distance behind him.
However, Li You possessed a naturally gentle and charismatic smile. Compared to Li Hongyuan's aloof and gloomy demeanor, it made him much more approachable and likable.
Simply put, this illegitimate son of the Emperor was very personable.
Upon meeting him, Jiang Ning understood why the Emperor had put him in charge of the spy system in Silla. At first glance, his demeanor was like a refreshing breeze, congenial and accommodating.