Is “He flattered the young emperor and sidelined Jiang Wei, leading to Shu's downfall.” true?
attested in history
According to the Records of the Three Kingdoms, Book of Shu, Biography of Dong Yun, Huang Hao was a crafty and favored courtier. After Dong Yun's death, he dominated the court, and Jiang Wei, fearing Huang Hao's harm, dared not return to Chengdu.
Huang Hao
In official history, he was a eunuch who manipulated power and destabilized the Shu Han government.