Who is the main figure who is a deer for a horse?

The idiom means a deer is a horse, and the protagonist is Zhao Gao, the eunuch of the Qin Dynasty. Idiom is a metaphor for deliberately reversing black and white and confusing right and wrong. Zhao Gao was the prime minister of Emperor Qin Ershi. He was the commander of CRRC House and the official of Fuxi. During his tenure, he monopolized power, used power for personal gain, taxed more, and his administration was more harsh. In addition, Zhao Gao was a great calligrapher in Qin and Han Dynasties.

The story of "Calling a Deer a Horse" introduced that during the reign of Qin Ershi Hu Hai, Zhao Gao, a eunuch, wanted to control state affairs and was afraid that someone would not obey him. So he sent someone to buy a deer, intending to test the attitude of the civil and military officials in the imperial court. In court, Zhao Gao told Hu Hai that he had got a good horse and wanted to give it to him. Hu Hai was very happy after hearing this, so he ordered Zhao Gao to pull the horse to the court and let the officials enjoy it together. When Hu Hai saw that it was a deer, he laughed at Zhao Gao for being confused. Zhao Gao insisted that it was a horse, and some officials were afraid of Zhao Gao's power, echoing Zhao Gao's claim that it was a horse, not a deer. But an honest official said it was a deer. Later, officials who said they were deer were secretly killed by Zhao Gao.