Who is Yang Guang? Is it bad?

Some people say that he killed his brother and father, which is certainly not impossible. But Emperor Taizong still killed his brother and younger brother ... I think Yang Guang is a man like Emperor Wu of Han Dynasty, with unlimited energy, ambition and long-term political vision. Yang Guang should also be a talented person, whether in literature or martial arts. But he is too proud to think that all his ideas are right, so that he can't see the beginning of the world and can't stand it. After 300-400 years of great division and turmoil, what the world needs is to do nothing like the rule of culture, not to make great efforts to build buildings. People all over the world, even literati, have no strong sense of belonging to the Sui Dynasty. At this time, building canals, levying Koryo and building palaces is simply suicide.