Sun Wen could not believe that he would be betrayed, let alone by his younger brother, Sun Jiaolong.
Their Sovereign Father has many children and many wives and concubines. As such, the competition between the siblings is quite intense. However, one of the reasons that Sun Wen managed to rise to the top was actually because of the support of his little brother. After all, the two of them are actually from the same mother.
Most of Sun Wen' siblings are also tactically minded, so they are weak when it comes to direct confrontation. The only exception being Sun Jiaolong, who since he was young had always advocated being strong, courageous, and fearless in battle.
So with his little brother's support in the muscle department and his tactical ability, Sun Wen was able to get an edge or advantage over his other competitors and acquired the position of Crown Prince.
However, things did not seem as simple as Sun Wen imagined.