The villain prince is three and a half years old

After completing "The Prince Training Plan", Xia Jing traveled to the Ning Dynasty in the game and was reincarnated as the ninth prince.
The ninth prince is only three and a half years old. His mother's family has lost power, and his mother has fallen out of favor. He is a marginalized and invisible person.
Good news, the biological mother turned evil two years later, tore apart all the concubines, took the throne in the palace, and became the mother of the country. In the end, she took advantage of the dynasty's weakness, deposed the prince and killed the emperor, becoming the first female emperor of the Ning Dynasty!
Bad news, the reason for his darkening is that he died.