Xu Shu

Xu Shu was a disciple of Sima Hui and an expert swordsman. He first served as strategist for Liu Bei.

Romance of the Three Kingdoms
In the novel, his mother was kidnapped by Cao Cao and he was forced to leave Liu Bei's side. Before his departure, he recommended Zhuge Liang as his successor. His mother's plea to see him was actually a ruse concocted by Cao Cao's advisers to make him leave Liu Bei. His mother was ashamed to see her son leave the virtuous Liu Bei for "the traitor Cao Cao" and hung herself. Devastated by his inability to see through the trick, his devotion to Shu strengthened and he swore to never tell Cao Cao any of his strategies.