yosei sho (taishi-sho)

He is one of the three Grand Officials of the Palace. Taishi is his title and not his name. It was his plan to bring Shūrei to the palace as the temporary wife of the Emperor.

He also had a master plan to expose the true mastermind of the plot to kill the Emperor. He says that he doesn't serve the country and is only loyal to a worthy Emperor. By introducing Shūrei to the palace, the Emperor was finally worthy to rule and Taihō Sa's plot to kill the Emperor was exposed.

He had been able to control the Black Wolf and the Wolves of the Wind, but after risking Shōka's daughter and Seiran's life, Shōka decided not to follow his orders any longer and vowed to kill him.

He served the previous emperor. He saw Taihō-Sa as a close friend of his for many years and was saddened by his passing, but thought that it had to be done. He and Taifū are also great friends.

He seems to be more than human since he was seen as a young man with a white aura surrounding him when he went to comfort his friend, Enjun, during his last moments. Later, it is shown that he is able to summon Enjun's spirit. It is later revealed that he is one of the eights sages, the Sage of Shi, that served the first Emperor.

He once made a pact with someone that he will only serve the emperor he deemed fitting and will do everything he can to help him survive and nothing more. That's why during the imperial succession battle eight years ago; he did not do anything to ensure that the country is in great condition. He did only the bare minimal to ensure the country will survive while he searched for the king worthy of him. When he realised that Ryūki was finally turning into the kind of king he was searching for, he made sure that no one threatens Ryūki's place on the throne.

Taishi-Shō's name has been revealed to be Yōsei by Eiki Hyō (Sa) in episode 36